Assessment of relationships between frailty and chronic pain: a bidirectional two-sample Mendelian randomisation study.

BACKGROUND: Previous observational studies have indicated a complex association between chronic pain and frailty. This study aimed to examine the bidirectional causal relationship between frailty and chronic pain and to quantify mediating effects of known modifiable risk factors. METHODS: A bidirectional two-sample Mendelian randomisation (MR) analysis was applied in this study. Summary genome-wide association statistics for frailty, as defined by both frailty index (FI) and Fried Frailty Score (FFS), pain at seven site-specific chronic pain (SSCP) (headache, facial, neck/shoulder, stomach/abdominal, back, hip and knee) and multisite chronic pain (MCP) were extracted from populations of European ancestry. Genetic instrumental variables strongly correlated with each exposure were selected. The inverse-variance-weighted method was the primary method used in the MR, supplemented by a range of sensitivity and validation analyses. Two-step MR analysis was undertaken to evaluate the mediating effects of several proposed confounders. RESULTS: Genetically predicted higher FI and FFS were associated with an increased risk of MCP and specific types of SSCP, including neck/shoulder pain, stomach/abdominal pain, back pain, hip pain and knee pain. In the reverse direction analysis, genetic liability to MCP was found to be associated with increased FI and FFS. These results remained consistent across sensitivity and validation assessments. Two-step MR suggested a mediating role for body mass index, smoking initiation, physical inactivity, educational attainment and depression. CONCLUSIONS: Our research provided genetic evidence that the association between frailty and chronic pain was bidirectional where the coexistence of both conditions will exacerbate each other.

Prognostic nutritional index and serum lactate dehydrogenase predict the prognosis of nasopharyngeal carcinoma patients who received intensity-modulated radiation therapy.

PURPOSE: This research aimed to evaluate the prognostic significance of baseline prognostic nutritional index (PNI) and lactate dehydrogenase (LDH) for the outcome of individuals diagnosed with non-metastatic nasopharyngeal carcinoma (NPC). METHODS: A retrospective analysis was conducted on data from 810 patients with non-metastatic NPC who underwent intensity-modulated radiation therapy (IMRT) with or without chemotherapy. The best cut-offs for PNI and LDH were identified by X-tile software to be 48.5 and 150, respectively. To find the independent prognostic factors for survival outcomes, univariate and multivariate regression analyses were conducted, and AUCs were used to compare their prognostic values. RESULTS: Multivariate analysis revealed that patients with PNI > 48.5 had better overall survival (OS) (HR: 0.502, P < 0.001), progression-free survival (PFS) (HR: 0.618, P < 0.001), and distant metastasis-free survival (DMFS) (HR: 0.637, P = 0.005). Higher LDH was associated with poorer OS (HR: 1.798, P < 0.001), PFS (HR: 1.671, P < 0.001), and DMFS (HR: 1.756, P < 0.001). The combination of low PNI and high LDH in non-metastatic NPC patients was correlated with poor OS (P < 0.001), PFS (P < 0.001), and DMFS (P < 0.001). The combination of PNI and LDH had the highest AUCs for predicting OS, PFS, and DMFS. CONCLUSIONS: PNI and LDH might become valuable predictors of the prognosis of non-metastatic NPC patients undergoing IMRT with or without chemotherapy. Prognostic accuracy can be enhanced by combining PNI and LDH.

The development and validation of a nomogram to determine neurological outcomes in cardiac arrest patients.

OBJECTIVES: This study aimed to investigate the variables that influence neurological functional restoration in cardiac arrest patients and construct a nomogram to predict neurofunctional prognosis. PATIENTS AND METHODS: We extracted the data from the Dryad database. Associations between patient variables and neurological outcomes were examined by logistic regression models. On the basis of these predictors, a prognostic nomogram was constructed. The identification and calibration of the prognostic nomogram were evaluated through the receiver operating characteristic (ROC) curve, the calibration curve, and the concordance index (C-index). RESULTS: A total of 374 cardiac arrest individuals were recruited in the research. Sixty percent of the participants had an adverse neurological result. The multivariable logistic regression analysis for poor neurological recovery, which showed patient age ≥ 65 years, previous neurological disease, witnessed arrest, bystander cardio-pulmonary resuscitation(CPR), cardiac arrest presenting with a non-shockable rhythm, total epinephrine dose ≥ 2.5 mg at the time of resuscitation and acute kidney injury(AKI) remained independent predictors for neurological outcomes. CONCLUSIONS: The novel nomogram based on clinical characteristics is an efficient tool to predict neurological outcomes in cardiac arrest patients, which may help clinicians identifying high-risk patients and tailoring personalized treatment regimens.

Intraperitoneal 5-Azacytidine Alleviates Nerve Injury-Induced Pain in Rats by Modulating DNA Methylation.

To investigate the role of DNA methylation in modulating chronic neuropathic pain (NPP), identify possible target genes of DNA methylation involved in this process, and preliminarily confirm the medicinal value of the DNA methyltransferases (DNMTs) inhibitor 5-azacytidine (5-AZA) in NPP by targeting gene methylation. Two rat NPP models, chronic constriction injury (CCI) and spinal nerve ligation (SNL), were used. The DNA methylation profiles in the lumbar spinal cord were assayed using an Arraystar Rat RefSeq Promoter Array. The underlying genes with differential methylation were then identified and submitted to Gene Ontology and pathway analysis. Methyl-DNA immunoprecipitation quantitative PCR (MeDIP-qPCR) and quantitative reverse transcription-PCR (RT-qPCR) were used to confirm gene methylation and expression. The protective function of 5-AZA in NPP and gene expression were evaluated via behavioral assays and RT-qPCR, respectively. Analysis of the DNA methylation patterns in the lumbar spinal cord indicated that 1205 differentially methylated fragments in CCI rats were located within DNA promoter regions, including 638 hypermethylated fragments and 567 hypomethylated fragments. The methylation levels of Grm4, Htr4, Adrb2, Kcnf1, Gad2, and Pparg, which are associated with long-term potentiation (LTP) and glutamatergic synapse pathways, were increased with a corresponding decrease in their mRNA expression, in the spinal cords of CCI rats. Moreover, we found that the intraperitoneal injection of 5-AZA (4 mg/kg) attenuated CCI- or SNL-induced mechanical allodynia and thermal hyperalgesia. Finally, the mRNA expression of hypermethylated genes such as Grm4, Htr4, Adrb2, Kcnf1, and Gad2 was reversed after 5-AZA treatment. CCI induced widespread methylation changes in the DNA promoter regions in the lumbar spinal cord. Intraperitoneal 5-AZA alleviated hyperalgesia in CCI and SNL rats, an effect accompanied by the reversed expression of hypermethylated genes. Thus, DNA methylation inhibition represents a promising epigenetic strategy for protection against chronic NPP following nerve injury. Our study lays a theoretical foundation for 5-AZA to become a clinical targeted drug.

Novel Bipolar High-Voltage Pulsed Radiofrequency Targeting the Cervical Sympathetic Chain for Treating Acute Herpetic Neuralgia.

INTRODUCTION: Postherpetic neuralgia (PHN) in the oral, maxillofacial, neck, and upper limb regions is a refractory neuropathic pain and severely affects the quality of life of patients. Because of the absence of ideal treatments for this condition, relieving pain in the acute stage and preventing the occurrence of PHN are of great clinical significance. However, the optimal intervention for this acute herpetic neuralgia remains obscure. OBJECTIVES: This study aimed to investigate whether bipolar high-voltage pulsed radiofrequency (PRF) targeting the cervical sympathetic chain could effectively treat acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce the incidence of PHN. MATERIALS AND METHODS: A total of 60 patients with acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions were enrolled. The radiofrequency group (n = 30) received bipolar high-voltage PRF under ultrasound guidance at the level of the transverse processes of C6 and C7 to modulate the cervical sympathetic chain. In the sham group (n = 30), the electrodes were simply placed at the same position as in the radiofrequency group, but no radiofrequency energy was applied. The same treatment was repeated in each group after 72 hours. If patients were reported to have a visual analog scale (VAS) score ≥4, they would receive oral tramadol and gabapentin as rescue analgesics. The VAS score, Pittsburgh Sleep Quality Index (PSQI), 36-Item Short Form Health Survey (SF-36) score, use of tramadol and gabapentin, incidence of PHN, and adverse reactions were recorded to assess the effect and safety of therapy during three months of follow-up. RESULTS: Decreased VAS scores, PSQI scores, and improved SF-36 scores were detected in the two groups at different time points after treatment (all p < 0.05). The VAS scores, PSQI scores, use of tramadol and gabapentin, and incidence of PHN were significantly lower, whereas the SF-36 scores were significantly higher in the radiofrequency group than in the Sham group (all p < 0.05). No serious adverseness related to the treatment was detected in either group. CONCLUSIONS: Bipolar high-voltage PRF treatment targeting the cervical sympathetic chain could effectively relieve acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce PHN incidence. The efficacy and safety of this novel treatment make it worthy of recommendation for clinical application.

Lumbar Sympathetic Ganglion Block for Cancer-Associated Secondary Lower Limb Lymphedema: A Retrospective Study.

BACKGROUND: Although lower limb lymphedema (LLL) is more or equally as frequent and harmful as upper limb lymphedema after cancer treatment, there are only a few studies on this topic. Cancer-related secondary LLL not only has physical implications, but also affects quality of life among patients who underwent gynecological cancer treatment. Despite numerous studies of various therapies, the optimal treatment for cancer-related LLL is still unknown. OBJECTIVES: We aimed to investigate the efficacy of lumbar sympathetic ganglion block (LSGB) in patients with secondary LLL in the present study. STUDY DESIGN: This study is a retrospective study. SETTING: A single academic hospital, outpatient setting. METHODS: A total of 30 patients with secondary unilateral LLL and failed complex decongestive treatment,  from January 2017 through May 2021, were reviewed for inclusion in this study. The patients underwent fluoroscopy-guided LSGB 2 times with the help of digital subtraction angiography at 3-day intervals. Leg circumference was measured, and the volume of the leg was calculated before surgery, on the first day after the first surgery, on the first day after the second surgery, and on the seventh day after the second surgery. The World Health Organization Quality of Life Instrument Questionnaire scores were monitored before and after LSGB. RESULTS: The leg circumference and volume decreased significantly from baseline after the treatment (P < 0.001). One week after 2 rounds of LSGB, the physical health score, psychological score, and social relationships score were higher than those before treatment (all P < 0.05). There was no difference in the environmental health score (P = 0.2731). LIMITATIONS: This study was limited by its sample size and retrospective observational design. CONCLUSIONS: LSGB can be a safe and effective treatment option for patients with secondary LLL after gynecological cancer treatment.

Effects of High-Voltage Pulsed Radiofrequency on the Ultrastructure and Nav1.7 Level of the Dorsal Root Ganglion in Rats With Spared Nerve Injury.

OBJECTIVES: To investigate the analgesic effect of high-voltage pulsed radiofrequency (HV-PRF) on the dorsal root ganglion (DRG) for neuropathic pain induced by spared nerve injury (SNI) in rats, especially the influence of this treatment on the DRG ultrastructure and voltage-gated sodium channel 1.7 (Nav1.7) level in the DRG. MATERIALS AND METHODS: One hundred fifty adult male Sprague-Dawley rats were randomly divided into five groups: Sham, SNI, Free-PRF, standard-voltage PRF (SV-PRF), and HV-PRF. The 45V-PRF and 85V-PRF procedures applied to the left L5 DRG were performed in SV-PRF group and the HV-PRF group, respectively, on day 7 after SNI, whereas no PRF was concurrently delivered in Free-PRF group. The paw mechanical withdrawal threshold (PMWT) was detected before SNI (baseline) and on days 1, 3, 7, 8, 10, 14, and 21. The changes of left L5 DRG ultrastructure were analyzed with transmission electron microscopy on days 14 and 21. The expression levels of Nav1.7 in left L5 DRG were detected by immunofluorescence and Western blot. RESULTS: Compared with the Free-PRF group, PMWT in the SV-PRF group and HV-PRF group were both significantly increased after PRF (all p < 0.05). Meanwhile, the PMWT was significantly higher in the HV-PRF group than that in the SV-PRF group on days 14 and 21 (all p < 0.05). There were statistically significant differences between the SV-PRF and Free-PRF groups (p < 0.05). Similarly, statistically significant difference was found between the HV-PRF and Free-PRF groups (p < 0.05). Especially, comparison of the SV-PRF group and the HV-PRF group revealed statistically significant difference (p < 0.05). The Nav1.7 levels were significantly downregulated in the SV-PRF group and HV-PRF groups compared to that in the Free-PRF group (all p < 0.01). A significantly lower Nav1.7 level was also found in the HV-PRF group compared to that in the SV-PRF group (p < 0.05). CONCLUSIONS: The HV-PRF produces a better analgesic effect than SV-PRF applied to the DRG in SNI rats. The underlying mechanisms may be associated with improving the histopathological prognosis and the downregulation of Nav1.7 levels in the DRG.