Short-term cervical spinal cord stimulation for central post-stroke pain: a case report and literature review.

Introduction: Post-stroke central pain is disabling yet ineffectively treated with routine medical intervention. In this study, the authors presented an alternative neuromodulation therapy and conducted a brief narrative literature review to examine current evidence of spinal cord stimulation treatment for central post-stroke pain. Case presentation: Here, the authors reported a case of severe post-stroke syndrome, who achieved satisfactory improvement of pain symptom, as well as muscle rigidity with a novel neuromodulation therapy of short-term implantation of cervical spinal cord stimulation. Clinical discussion: It remains a great challenge in the management of post-stroke pain, which in turn significantly reduces the quality of life and worsens the burden on the public health system. Spinal cord stimulation therapy is an emerging neuromodulation approach to restore pathological pain status and functional impairment to provide a prospective insight into neuromodulation and rehabilitation options in the management of post-stroke syndrome. Conclusion: A potential role of spinal cord stimulation in the treatment of post-stroke pain is proposed in combined with traditional medication or other neuromodulation strategies, to achieve better control of pain in the future.

Plasma cell-free DNA 5-hydroxymethylcytosine and whole-genome sequencing signatures for early detection of esophageal cancer.

Esophageal cancer is a highly incidence and deadly disease with a poor prognosis, especially in developing countries. Owing to the lack of specific symptoms and early diagnostic biomarkers, most patients are diagnosed with advanced disease, leading to a 5-year survival rate of less than 15%. Early (n = 50) and middle-advanced (n = 50) esophageal squamous cell carcinoma (ESCC) patients, as well as 71 healthy individuals, underwent 5-hydroxymethylcytosine (5hmC) sequencing on their plasma cell-free DNA (cfDNA). A Northern Chinese cohort of cfDNA 5hmC dataset of 150 ESCC patients and 183 healthy individuals were downloaded for validation. A diagnostic model was developed using cfDNA 5hmC signatures and then improved by low-pass whole genome sequencing (WGS) features of cfDNA. Conserved cfDNA 5hmC modification motifs were observed in the two independent ESCC cohorts. The diagnostic model with 5hmC features achieved an AUC of 0.810 and 0.862 in the Southern and Northern cohorts, respectively, with sensitivities of 69.3-74.3% and specificities of 82.4-90.7%. The performance was well maintained in Stage I to Stage IV, with accuracy of 70-100%, but low in Stage 0, 33.3%. Low-pass WGS of cfDNA improved the AUC to 0.934 with a sensitivity of 82.4%, a specificity of 88.2%, and an accuracy of 84.3%, particularly significantly in Stage 0, with an accuracy up to 80%. 5hmC and WGS could efficiently differentiate very early ESCC from healthy individuals. These findings imply a non-invasive and convenient method for ESCC detection when clinical treatments are available and may eventually prolong survival.

Establishing a new model of cancer neuropathic pain in rats.

To guide the treatment of malignant neuropathic pain (MNP) in clinical practice, by inoculating MADB-106 breast cancer cells into the right L4 nerve root in Sprague-Dawley rats, a rat model of MNP was established, providing basic conditions for the study of neuropathic pain and development and application of therapeutic drugs. As the tumor grew over time, it pressed the nerve roots, causing nerve damage. The spinal nerve ligation (SNL) model, which is a neuropathic pain model widely used in rats, was compared with the L4 nerve root SNL model, and histologic examination of the nerve tissue of both models was performed by electron microscopy. In addition to the infiltration and erosion of the L4 nerve by tumor cells, the tumor tissue gradually grew and compressed the L4 nerve roots, resulting in hyperalgesia of the rat's posterior foot on the operative side. Some spontaneous pain phenomena were also observed, such as constant lifting or licking of the posterior foot on the operative side under quiet conditions. Electron microscopy images showed that nerve injury was due to progressive compression by the tumor, cells of which were visualized, but the injury was lighter than that in SNL rats. Imaging showed a paravertebral tumor near the L4 nerve root in the carcinomatous neuropathic pain model rat. These results suggest that progressive compression of the nerve by a malignant tumor leads to nerve damage similar to the behavioral changes associated with chronic compression injury resulting from a loose ligature of the nerve. The cancer neuropathologic pain model at the L4 nerve root was successfully established in Sprague-Dawley rats.

Repair Effects of Bone Marrow Mesenchymal Stem Cells on Demyelination of Trigeminal Ganglion in Rats with Trigeminal Neuralgia.

OBJECTIVE: The current study investigated the effects of bone marrow mesenchymal stem cells (BMSCs) on pain behavior in rats with trigeminal neuralgia induced by infraorbital nerve chronic constriction injury (ION-CCI), and the repair effects of BMSCs on pathological changes in trigeminal ganglion demyelination. METHODS: BMSCs or phosphate-buffered saline (PBS) alone were injected around trigeminal ganglion in ION-CCI rats via a rat brain stereotaxic apparatus. Mechanical pain threshold (von Frey test) and face grooming behavior were measured in each group. Recovery of demyelination of trigeminal ganglion was observed via electron microscopy 2 weeks later, and BMSC differentiation was observed via immunofluorescence. RESULTS: Rats in the BMSC group exhibited significant improvements in mechanical pain threshold and face grooming behavior compared with the PBS group. BMSCs could repair demyelinating changes in trigeminal ganglion in ION-CCI rats. Only cells expressing GFAP, S-100, and p75 were observed via immunofluorescence, and no PKH67-labeled BMSCs were observed in the trigeminal ganglion. No BMSC differentiation was observed in the trigeminal ganglion. CONCLUSION: Injection of BMSCs around the trigeminal ganglion could relieve trigeminal neuralgia effectively and repair trigeminal ganglion demyelination. No differentiation of BMSCs injected around the trigeminal ganglion into Schwann cells was observed. The mechanism of trigeminal neuralgia demyelination repair requires further investigation.

A Patient With a Foreign Body in Mediastinum That Penetrated Into the Bronchus.

We report the rare case of a patient who had a foreign body in the mediastinum and trachea caused by trauma due to epileptic seizures. A 52-year-old man had an epileptic seizure 3 months before visiting our hospital and had an injury to his neck caused by a broken glass cabinet. Computed tomography scan revealed a foreign body in the mediastinum and trachea. After a detailed discussion among members of the multidisciplinary team, surgery was successfully performed to remove the foreign body. This rare case may help provide a reference for diagnosing and treating a mediastinal and tracheobronchial foreign body.

Clinical Outcome of Pulsed-Radiofrequency Combined With Transforaminal Epidural Steroid Injection for Lumbosacral Radicular Pain Caused by Distinct Etiology.

BACKGROUND: Lumbosacral radicular pain (LSRP) can be caused by disc herniation, spinal stenosis, and failed back surgery syndrome. The clinical effect of pulsed-radiofrequency (PRF) combined with transforaminal epidural steroid injection (TESI) for radiating pain in different population remains unclear. METHODS: We retrospectively reviewed the medical recordings of patients with LSRP caused by different etiologies, who underwent PRF and TESI treatment. The primary clinical outcome was assessed by a 10-point Visual Analog Scale (VAS) pre- and post-treatment. RESULTS: A total of 34 LSRP patients were identified and classified into 3 subgroups (disc herniation, spinal stenosis, and failed back surgery syndrome). The overall immediate pain reduction was 4.4 ± 1.1 after procedure. After a median follow-up of 9.5 months, the VAS decreased from 6.5 ± 1.0 to 2.4 ± 1.9 at the last follow-up. CONCLUSION: PRF combined with TESI is an effective approach to treat persistent LSRP in distinct population.

Machine Learning Models to Predict Primary Sites of Metastatic Cervical Carcinoma From Unknown Primary.

Metastatic cervical carcinoma from unknown primary (MCCUP) accounts for 1-4% of all head and neck tumors, and identifying the primary site in MCCUP is challenging. The most common histopathological type of MCCUP is squamous cell carcinoma (SCC), and it remains difficult to identify the primary site pathologically. Therefore, it seems necessary and urgent to develop novel and effective methods to determine the primary site in MCCUP. In the present study, the RNA sequencing data of four types of SCC and Pan-Cancer from the cancer genome atlas (TCGA) were obtained. And after data pre-processing, their differentially expressed genes (DEGs) were identified, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these significantly changed genes of four types of SCC share lots of similar molecular functions and histological features. Then three machine learning models, [Random Forest (RF), support vector machine (SVM), and neural network (NN)] which consisted of ten genes to distinguish these four types of SCC were developed. Among the three models with prediction tests, the RF model worked best in the external validation set, with an overall predictive accuracy of 88.2%, sensitivity of 88.71%, and specificity of 95.42%. The NN model is the second in efficacy, with an overall accuracy of 82.02%, sensitivity of 81.23%, and specificity of 93.04%. The SVM model is the last, with an overall accuracy of 76.69%, sensitivity of 74.81%, and specificity of 90.84%. The present analysis of similarities and differences among the four types of SCC, and novel models developments for distinguishing four types of SCC with informatics methods shed lights on precision MCCUP diagnosis in the future.

Facile chemoenzymatic synthesis of Lewis a (Lea) antigen in gram-scale and sialyl Lewis a (sLea) antigens containing diverse sialic acid forms.

An efficient streamlined chemoenzymatic approach has been developed for gram-scale synthesis of Lewis a angtigen (LeaßProN3) and a library of sialyl Lewis a antigens (sLeaßProN3) containing different sialic acid forms. Intially, commercially available inexpensive N-acetylglucosamine (GlcNAc) was converted to its N'-glycosyl p-toluenesulfonohydrazide in one step. Followed by chemical glycosylation, GlcNAcßProN3 was synthesized using this protecting group-free method in high yield (82%). Sequential one-pot multienzyme (OPME) ß1-3-galactosylation of GlcNAcßProN3 followed by OPME α1-4-fucosylation reactions produced target LeaßProN3 in gram-scale. Structurally diverse sialic acid forms was successfully introduced using a OPME sialylation reation containing a CMP-sialic acid synthetase and Pasteurella multocida α2-3-sialyltransferase 1 (PmST1) mutant PmST1 M144D with or without a sialic acid aldolase to form sLeaßProN3 containing naturally occurring or non-natural sialic acid forms in preparative scales.

Breakthrough Cancer Pain Is Associated with Spinal Gap Junction Activation via Regulation of Connexin 43 in a Mouse Model.

Breakthrough cancer pain (BTcP) is a high-intensity, short-duration, unpredictable and uncontrollable pain. Recent studies have shown that activation of gap junction (GJ) in spinal cord plays an important role in the pathogenesis of BTcP. We examined the expressions of Glial fibrillary acidic protein (GFAP), connexin (Cx) 43 protein and phosphorylation of Cx43 (p-Cx43) in the spinal cord of mice. In addition, we investigated the effects of Gap26, a selective GJ blocker, on the expressions of GFAP, Cx43 and p-Cx43 in BTcP mice. We found that the expressions of GFAP and Cx43 proteins were significantly upregulated while p-Cx43 was down-regulated in the spinal cord in a mouse model of BTcP. The overexpression of Cx43 protein in the spinal cord increased GJ formation and enhanced BTcP. The variation of the ratio of p-Cx43/T-Cx43 (total Cx43) affected the function of GJ to induce BTcP. Furthermore, BTcP was alleviated by Gap26 via reducing pain hypersensitivity. The inhibition of Cx43 and p-Cx43 by Gap26 attenuated BTcP but the p/T ratio of Cx43 remained unchanged in BTcP mice. We reveal that the expression and phosphorylation of Cx43 affected BTcP and GJ activation facilitated BTcP via a Cx43-mediated signaling in the spinal cord. The finding may provide a scientific rationale for discovery and development of novel therapeutic targets for the treatment of BTcP clinically.

Study of breakthrough cancer pain in an animal model induced by endothelin-1.

Cancer patients with bone metastases often suffer breakthrough pain. However, little progress has been made in the treatment of breakthrough pain and its associated mechanism(s) in the patient with cancer due to lacking of resembling and predictive animal models. We previously have demonstrated that endothelin-1 plays an important role in breakthrough cancer pain. In the present study, we have established an animal model of breakthrough cancer pain induced by endothelin-1. The animal model of breakthrough cancer pain is strictly followed the definition and meets the characteristics of breakthrough pain. The model is reliable, reproducible and easy to be produced. To our knowledge, this is the first report for establishing such an animal model. In addition, we also found that a selective ETA receptor antagonist BQ-123 could reverse endothelin-1 induced breakthrough pain. We further studied the characteristics of pain behaviors such as hind limb use score and voluntary wheel running as well as the electrophysiology of sciatic nerve fibers with the model. The murine model shows high resemblance compared to the breakthrough cancer pain in the patients with cancer clinically. It provides a platform for further study of the pathogenesis of breakthrough cancer pain and targeted intervention.

Correlations between plasma endothelin-1 levels and breakthrough pain in patients with cancer.

Endothelin-1 (ET-1) may be involved in driving pain in patients with advanced cancer. However, a few studies focus on the role of ET-1 in breakthrough pain (BP). The aim of this pivotal study was to explore the correlation between the plasma (ET-1) level and BP intensity. A total of 40 patients were enrolled in the study, and they were divided into two groups: BP group and non-BP group. Moreover, 20 healthy adults were used as the normal control group. Pain intensity was measured using visual analog scale (VAS) scores of 1-10. Plasma ET-1 levels were detected by an ET radioimmunoassay kit. Subsequently, the correlation of ET-1 level with the VAS score and cancer types was analyzed by Pearson's correlation coefficient. The plasma ET-1 level in the BP group (35.31±8.02 pg/mL) was higher than that in the non-BP group (29.51±6.78 pg/mL) and the normal control group (24.77±10.10 pg/mL, P<0.05). In addition, the VAS score in the BP group (7.45±0.82) was higher than that in the non-BP group (2.80±1.23, P<0.05). The plasma ET-1 level was positively correlated with the VAS score of the BP group (Pearson's r=0.42). There was no significant correlation between the plasma ET-1 level and VAS score of the non-BP group (Pearson's r=-0.22) or/and cancer types (P>0.05). The elevated plasma ET-1 levels were positively related to BP, and targeting ET-1 may provide a novel pain-reducing therapeutic treatment in BP.

Effect of perioperative intravenous flurbiprofen axetil on chronic postmastectomy pain.

OBJECTIVE: To explore whether perioperative intravenous flurbiprofen axetil can reduce the incidence and intensity of chronic pain for breast cancer after surgical treatment. METHODS: This randomized, double-blind, controlled trial enrolled 60 patients undergoing mastectomy and axillary lymph node dissection under general anesthesia. All patients accepted Hospital Anxiety and Depression Scale (HAD) tests the day before the surgery to evaluate depression and anxiety. The patients were randomly assigned to receive either 50 mg flurbiprofen axetil intravenously 15 minutes before the surgical incision and 6 hours later (group F) or intravenous 5 mL intralipid as a control (group C). All patients received patient-controlled intravenous analgesia (PCIA) with fentanyl postoperatively. Peripheral venous blood samples were drawn before the surgery, at 4 and 24 h after the surgery to detect the plasma level of PGE2 and tumor necrosis factor-α (TNF-α). Postoperative fentanyl consumption, Numerical Rating Scale (NRS) scores and adverse effects were recorded at 2, 6, 12, 24 and 48 h after the surgery. The duration and intensity of pain were followed up by telephone at the 2nd-12th month after the surgery. RESULTS: The incidence of pain at 2, 4, 6, and 12 months after the breast surgery was 33%, 20%, 15%, and 10%, respectively, and the average pain score was 0.77, 0.57, 0.28, and 0.18, respectively. Compared with group C, the scores of pain in group F were significantly lower at 2, 4, 6 and 12 months postoperatively (F=7.758, P=0.007). The incidence of pain in group F was significantly lower at 2, 4 and 6 months postoperatively (P<0.05). There was no significant difference in the incidence of pain between the groups at 12 months postoperatively (P>0.05). Preoperatively and at 4 and 24 h after the surgery, there was no significant difference in the level of TNF-α between the two groups (F=0.530, P=0.470); but plasma concentration of PGE2 in group F was significantly lower than that in group C (F=5.646, P=0.021). No patients developed abnormal bleeding, peptic ulcer, impaired liver or renal function and respiratory depression. CONCLUSION: Perioperative intravenous infusion of 100 mg flurbiprofen axetil can decrease the intensity and incidence of chronic pain for breast cancer after surgical treatment.

Surgery upregulates high mobility group box-1 and disrupts the blood-brain barrier causing cognitive dysfunction in aged rats.

AIM: Postoperative cognitive dysfunction (POCD) is a growing and largely underestimated problem without defined etiology. Herein, we sought to determine the relationship between cognitive decline, blood-brain barrier (BBB) permeability, and inflammation, namely high mobility group box-1 (HMGB1), after surgery in aged rats. METHODS: Aged rats were randomly assigned as surgery group (n = 45, splenectomy under general anesthesia), anesthesia (n = 45, 2% isoflurane for 2 h), and naïve control (n = 15). Markers of inflammation were measured in plasma and brain. Blood-brain barrier ultrastructure and permeability were measured by transmission electron microscope (TEM) and IgG immunohistochemistry. Cognitive function was assessed in a reversal learning version of the Morris water maze (MWM). RESULTS: Surgical trauma under general anesthesia caused distinct changes in systemic and central proinflammatory cytokines. Levels of HMGB1 and the receptor for advanced glycation end products (RAGE) were significantly upregulated in the hippocampus of operated animals. Immunohistochemistry and TEM showed BBB disruption induced by surgery and anesthesia. These molecular changes were associated with cognitive impairment in latency with the MWM up to postoperative day 3. CONCLUSIONS: HMGB1 and RAGE signaling appear pivotal mediators of surgery-induced cognitive decline and may contribute to the changes in BBB permeability after peripheral surgical trauma.

[Expression of NR2B in the spinal dorsal horn and dorsal root ganglia in mice with bone cancer pain].

OBJECTIVE: To investigate the manifestation of ethology and the immunohistochemistry results of the 2B Subunits of N-methyl-D-aspartate receptors (NR2B) in the spinal cord dorsal horn and dorsal root ganglia (DRG) in mice with bone cancer pain and their correlation, and to discuss the role of NR2B in the generation and maintenance of bone cancer pain. METHODS: Forty-five male C57BL/6 mice were randomly divided into 3 groups: a model group (n=15), 2×10(6) cells in 10 µL D-Hank's were injected into the left femur of mice;a sham group(n=15), only 10 µL D-Hank's injected into the left femur of mice;and a normal control group(n=15), no treatment. Spontaneous lifting duration and mechanical withdrawal threshold of the hind paw of mice were measured on alternative days throughout the experiment. Bones from 5 mice in each group were stained with HE on Day 7, 15, and 23 after the inoculation and segments of lumbar spinal cord and L(4) DRG were taken to detect NR2B by immunohistochemistry. RESULTS: Bone cancer pain models were successfully established and confirmed by ethology and histology. The immunohistochemical positive indexes of NR2B were significantly higher in the model group than in the sham group and the control group. In the model group there were obvious differences either between Day 7 and Day 15, or between Day 7 and Day 23 (P<0.05). On Day 23, the immunohistochemical positive indexes of NR2B in the ipsilateral spinal cord dorsal horn of all groups, and L(4) DRG were positively correlated with the spontaneous lifting duration of ipsilateral hindpaw (r=0.976, P<0.001; r=0.882, P<0.001, respectively), negatively correlated with the mechanical withdrawal threshold of ipsilateral hindpaw (r=-0.879, P<0.001; r=-0.760, P=0.001, respectively). CONCLUSION: The immunohistochemical positive indexes of NR2B are increased and significantly correlated with the manifestation of ethology. NR2B in the spinal cord and L(4) DRG may participate and mediate in forming and developing hyperalgesia in bone cancer pain.

[NMDA receptor and NOS in morphine tolerance in mice with bone cancer].

OBJECTIVE: To set up a mouse model with bone cancer to simulate the morphine tolerance and explore its mechanism. METHODS: Forty C57BL/6 male mice were divided into 4 groups: Group 1 and Group 2 were firstly set up as bone cancer pain models. Morphine (10 mg/kg) was sequentially administered subcutaneously twice daily in Group 1 and normal saline was administered in Group 2 as the control group. Similar to Group 1 and Group 2, morphine (10 mg/kg) was administered subcutaneously twice daily in Group 3 and normal saline was administered in Group 4 as the control group. To set up morphine tolerance model, we injected morphine continuously for 7 days. From Day 1 to Day 7 after the morphine injection, we measured the mice hind paw withdrawal threshold in the von Frey hair test every other day. NMDA receptor 1 (NMDA1) and nitric oxide synthase (NOS) were measured on Day 7 after the morphine injection. RESULTS: The mice hind paw withdrawal threshold in the von Frey hair test in Group 1 increased on Day 1,3, and 5 after the morphine injection compared with the paw withdrawal threshold in Group 2 and had the same threshold as Group 2 on Day 7. The mice hind paw withdrawal threshold in the von Frey hair test in Group 3 increased on Day 1,3, and 5 after the morphine injection compared with the paw withdrawal threshold in Group 4 and had the same threshold as Group 4 on Day 7. The grey scales and integral optical density (IOD) of NMDAR1 and the level of NOS in the spinal dorsal horn were higher in Group 1, Group 2, and Group 3 compared with those in Group 4 (P<0.05 or P<0.01), and the grey scales and IOD of NMDAR1 in Group 2 was higher than that in Group 1 (P<0.05). CONCLUSION: NMDA receptors and NOS may play important roles in morphine tolerance in mice with bone cancer pain.

[Establishment and evaluation of a bone cancer pain model].

OBJECTIVE: To explore the feasibility of a bone cancer pain model by injecting the Lewis lung carcinoma cells into the femur bone marrow cavity of C57BL/6 mice. METHODS: Sixty clear grade male C57BL/6 mice (body weight 18 approximately 20 g) were randomly divided into 4 groups(15 in each group). Cancer cell inoculated group: 2*10(6) Lewis lung carcinoma cells in 10 microL PBS were injected into the left femur bone marrow cavity, and the other 3 control groups were injected the heat inactivated Lewis cells, PBS, or a false operation respectively. Spontaneous lifting time and mechanical allodynia threshold of the mice hind paw were measured in the alternative days throughout the experiment. The structural damage of the femur was monitored by radiogram on the 7th,15th, and 23rd day respectively,and the pathohistological changes of the femur bones were observed by HE staining on the same days. RESULTS: Those mice that received intra-femur innoculation of Lewis lung carcinoma cells gradually developed the spontaneous pain, which was began on the 11th day after the innoculation, and followed by mechanical allodynia. The course of flinch lasted in the later experimental session. The 50% Von Frey threshold was significantly decreased on the 13th day after the innoculation, and the mechanical allodynia lasted the whole experimental period. On the 23rd day after the innoculation, X-ray film showed that the medullary cavity of ipsilateral distal femur was filled with tumor cells, and the cortical bone became thick; furthermore, the tumor cells invaded the peripheral muscles. CONCLUSION: Injecting the Lewis lung carcinoma cells into the femoral medullary cavity of C57BL/6 mice can successfully establish a murine bone cancer pain model, and the murine model shows much resemblance compared with the human bone cancer pain.

[Correlation between dynamic contrast-enhanced MRI and expression of microvascular density in the glioma].

OBJECTIVE: To explore the correlation between microvascular density (MVD) and dynamic contrast-enhanced MRI in the glioma. METHODS: We examined 35 patients with histologically verified glioma. Gadolinium-enhanced dynamic TurboFLASH imaging was performed preoperatively in all patients followed by conventional MRI. The steepest slope (SSmax) of curve and corresponding Tm1 in "first-pass" phase were obtained by analyzing time-signal curve. All specimens were immunostained with anti-human Factor VIII relative antigen monoclonal antibody postoperatively by streptavidin-peroxidase method to obtain the MVD. The correlation between SSmax, Tm1, and MVD was analyzed. RESULTS: SSmax was positively correlated with MVD (r = 0.640, P < 0.01). Tml was negatively correlated with MVD (r = -0.671, P < 0.01). CONCLUSION: The MVD correlates obviously with SSmax and Tml in the glioma. Analyzing the time-signal curve of dynamic contrast-enhanced MRI is helpful to predict the angiogenesis in the glioma.