Development and validation of a novel combinatorial nomogram model to predict in-hospital deaths in heart failure patients.

BACKGROUND: The purpose of this study was to develop a Nomogram model to identify the risk of all-cause mortality during hospitalization in patients with heart failure (HF). METHODS: HF patients who had been registered in the Medical Information Mart for Intensive Care (MIMIC) III and IV databases were included. The primary outcome was the occurrence of all-cause mortality during hospitalization. Two Logistic Regression models (LR1 and LR2) were developed to predict in-hospital death for HF patients from the MIMIC-IV database. The MIMIC-III database were used for model validation. The area under the receiver operating characteristic curve (AUC) was used to compare the discrimination of each model. Calibration curve was used to assess the fit of each developed models. Decision curve analysis (DCA) was used to estimate the net benefit of the predictive model. RESULTS: A total of 16,908 HF patients were finally enrolled through screening, of whom 2,283 (13.5%) presented with in-hospital death. Totally, 48 variables were included and analyzed in the univariate and multifactorial regression analysis. The AUCs for the LR1 and LR2 models in the test cohort were 0.751 (95% CI: 0.735∼0.767) and 0.766 (95% CI: 0.751-0.781), respectively. Both LR models performed well in the calibration curve and DCA process. Nomogram and online risk assessment system were used as visualization of predictive models. CONCLUSION: A new risk prediction tool and an online risk assessment system were developed to predict mortality in HF patients, which performed well and might be used to guide clinical practice.

Differential roles of phosphorylated AMPA receptor GluR1 subunits at Serine-831 and Serine-845 sites in spinal cord dorsal horn in a rat model of post-operative pain.

Previous studies have demonstrated that the enhanced levels of phosphorylated α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor GluR1 subunits at Serine-831 (pGluR1-Ser-831) and Serine-845 (pGluR1-Ser-845) in the spinal cord dorsal horn are involved in central sensitization of inflammatory pain. However, whether the phosphorylatory regulation of AMPA receptor GluR1 subunits is implicated in the development and maintenance of post-operative pain remains unclear. The current study aims to examine the functional regulation of AMPA receptor GluR1 subunit through its phosphorylation mechanism during the period of post-operative painful events in rats. Our data indicated that the expression of pGluR1-Ser-831 in ipsilateral spinal cord dorsal horn increased significantly at 3 h after incision, then decreased gradually, and returned to the normal level 3 day post-incision. Meanwhile, the expression of pGluR1-Ser-845 and GluR1 in ipsilateral spinal cord dorsal horn remained unchanged. The cumulative pain scores increased at 3 h after incision, gradually decreased afterwards and returned to the baseline values at 4 day after incision and the trend was almost parallel to the expression changes of pGluR1-Ser-831 in spinal dorsal horn. Intrathecal injection of a calcium-dependent protein kinase (PKC) inhibitor, Gö6983 (10 µM), significantly reversed the incision-mediated over-expression of pGluR1-Ser-831 in spinal dorsal horn at 3 h after incision and decreased the cumulative pain scores as well. These results indicate that the phosphorylation of GluR1 subunits at Serine-831 and Serine-845 sites might be differentially regulated following surgical procedures and support a neurobiological mechanism of post-operative pain involved in phosphorylation of AMPA subunits GluR1-Ser-831, but not pGluR1-Ser-845. Our study suggests that the therapeutic targeting the phosphorylation regulation of AMPA receptor GluR1 subunit at Serine-831 site would be potentially significant for treating postoperative pain.

NK-1-receptor-mediated lesion of spinal post-synaptic dorsal column neurons might improve intractable visceral pain of cancer origin.

The cancer-related visceral pain has traditionally been frustrating to treat by either medical or surgical means. Recent investigations from bench and bedside have suggested that a critical visceral nociceptive pathway originates from post-synaptic dorsal column (PSDC) neurons located in the central area of the spinal-cord. Interruption of the PSDC pathway using different surgical approaches effectively relieves intractable visceral pain in cancer patients. However, the indications of surgical lesion of DC are very limited in clinical setting because of the surgical risks and complications. Thus, a means of high-specific pharmacological lesion of DC pathway is necessary. Some evidence has shown that spinal PSDC neurons start to express neurokinin-1 (NK-1) receptors after visceral stimulation, suggesting new targets for the development of pharmacological strategies for the control of visceral pain. Here, we present our hypothesis that the targeted cytoxin composed of substance P coupled to the cytotoxic ribosome inactivating protein, saporin, might selectively destroy spinal PSDC neurons expressing NK-1 receptors, which will lead to pharmacological interruption of PSDC pathway and will greatly improve intractable visceral pain of cancer origin. Based on the data from related research, we believe that the current therapy we propose might be one of the optimal pharmacological approaches to replace the neurosurgical interruption of DC pathway and could be used for cancer-related visceral pain in wider clinical indications.

Effects of anesthetic propofol on release of amino acids from the spinal cord during visceral pain.

As one of general anesthetics, propofol, has been used for surgical procedures of visceral organs. However, the mechanisms underlying the action of propofol on visceral nociception remain controversial. The aim of this study is to test whether the antinociception of systemic administration of propofol against visceral stimuli is related to the changes in release of excitatory and inhibitory amino acids in the spinal cord. The spinal microdialysis catheters were implanted subarachnoidally via the atlanto-occipital membrane in healthy SD rats. The rats received an intraperitoneal injection of acetic acid for visceral pain induction 10min after intraperitoneal pretreatment with vehicle or propofol (100mg/kg). The acetic acid-induced writhing assay was used to determine the degree of antinociception. Cerebrospinal fluid dialysate was collected by microdialysis from the spinal subarachnoid space before pretreatment and after visceral pain induction. Visceral pain-induced release of amino acids into the dialysate, including glutamate, aspartate, and γ-amino butyric acid was evaluated by measuring the changes in the concentrations of these amino acids. Acetic acid increased release of aspartate and glutamate, and decreased release of γ-amino butyric acid in the cerebrospinal fluid as measured by microdialysis. Pretreatment with propofol significantly decreased writhing responses induced by visceral pain, suppressed the visceral pain-induced aspartate and glutamate release, and reversed the decreased release of γ-amino butyric acid in the cerebrospinal fluid. These data provide evidence for a potential mechanism for the antinociceptive effects of propofol on visceral nociception.