Int Immunopharmacol. 2024 Apr 10;132:112030. doi: 10.1016/j.intimp.2024.112030. Online ahead of print.

ABSTRACT

Mast cells (MCs) play a significant role in various diseases, and their activation and degranulation can trigger inflammatory responses and barrier damage. Several studies have indicated that vagus nerve stimulation (VNS) exerts ameliorates neurological injury, and regulates gut MC degranulation. However, there is limited research on the modulatory effect of VNS on MCs in both the gut and brain in brain ischemia-reperfusion (I/R) injury in this process. We aim to develop a minimally invasive, targeted and convenient VNS approach to assess the impact of VNS and to clarify the relationship between VNS and MCs on the prognosis of acute ischemic stroke. We utilized middle cerebral artery occlusion/reperfusion (MCAO/r) to induce brain I/R injury. After the experiment, the motor function and neurofunctional impairments of the rats were detected, and the gastrointestinal function, blood-brain barrier (BBB) and intestinal barrier damage, and systemic and local inflammation were evaluated by Nissl, TTC staining, Evans blue, immunofluorescence staining, transmission electron microscopy, western blot assays, ELISA, and fecal 16S rRNA sequencing methods. Our research confirmed that our minimally invasive VNS method is a novel approach for stimulating the vagus nerve. VNS alleviated motor deficits and gastrointestinal dysfunction while also suppressing intestinal and neuroinflammation. Additionally, VNS ameliorated gut microbiota dysbiosis in rats. Furthermore, our analysis indicated that VNS reduces chymase secretion by modulating MCs degranulation and improves intestinal and BBB damage. Our results showed that VNS treatment can alleviate the damage of BBB and colonic barrier after cerebral I/R by modulating mast cell degranulation, and alleviates systemic inflammatory responses.

PMID:38603861 | DOI:10.1016/j.intimp.2024.112030

Psychophysiology. 2024 Apr 11:e14584. doi: 10.1111/psyp.14584. Online ahead of print.

ABSTRACT

There is a growing interest in the clinical application of transcutaneous auricular vagus nerve stimulation (taVNS). However, its effect on cortical excitability, and whether this is modulated by stimulation duration, remains unclear. We evaluated whether taVNS can modify excitability in the primary motor cortex (M1) in middle-aged and older adults and whether the stimulation duration moderates this effect. In addition, we evaluated the blinding efficacy of a commonly reported sham method. In a double-blinded randomized cross-over sham-controlled study, 23 healthy adults (mean age 59.91 ± 6.87 years) received three conditions: active taVNS for 30 and 60 min and sham for 30 min. Single and paired-pulse transcranial magnetic stimulation was delivered over the right M1 to evaluate motor-evoked potentials. Adverse events, heart rate and blood pressure measures were evaluated. Participant blinding effectiveness was assessed via guesses about group allocation. There was an increase in short-interval intracortical inhibition (F = 7.006, p = .002) and a decrease in short-interval intracortical facilitation (F = 4.602, p = .014) after 60 min of taVNS, but not 30 min, compared to sham. taVNS was tolerable and safe. Heart rate and blood pressure were not modified by taVNS (p > .05). Overall, 96% of participants detected active stimulation and 22% detected sham stimulation. taVNS modifies cortical excitability in M1 and its effect depends on stimulation duration in middle-aged and older adults. taVNS increased GABA_Aergic inhibition and decreased glutamatergic activity. Sham taVNS protocol is credible but there is an imbalance in beliefs about group allocation.

PMID:38602055 | DOI:10.1111/psyp.14584

Gland Surg. 2024 Mar 27;13(3):351-357. doi: 10.21037/gs-23-428. Epub 2024 Mar 20.

ABSTRACT

BACKGROUND: Skin electrodes have been reported to be a useful alternative recording method for intraoperative neuromonitoring (IONM) and show typical electromyography (EMG) waveforms while overcoming the shortcomings of the EMG endotracheal tube. However, the skin electrodes showed relatively lower evoked amplitudes than other recording methods. In this study, we analyzed normative EMG data using skin electrodes and factors that affect the evoked amplitude of thyroid IONM.

METHODS: In total, 167 patients [242 nerves at risk (NAR)] who underwent thyroidectomy under IONM with adhesive skin electrodes were analyzed. A pair of skin electrodes was attached to the lateral border of the lamina of the thyroid cartilage. Evoked EMG data, including mean amplitude and latency, obtained after stimulation of the recurrent laryngeal nerve (RLN) and vagus nerve (VN), were collected and analyzed.

RESULTS: The mean amplitudes of RLN and VN recorded via skin electrodes were 255.48±96.53 and 236.15±69.72 μV, respectively. The mean latency of the right and left RLN was 3.22±0.03 and 3.49±0.08 mS, respectively. The mean latency of the right and left VN was 5.37±0.80 and 7.57±0.10 mS, respectively. The mean amplitude was significantly lower in the obesity, male, and total thyroidectomy (TT) groups. As body mass index (BMI) and age increased, the amplitude of EMG tended to decrease significantly.

CONCLUSIONS: The evoked amplitude recorded with the skin electrodes was relatively low. A larger surgical extent, obesity, male sex, and age >55 years showed significantly lower evoked amplitudes.

PMID:38601295 | PMC:PMC11002475 | DOI:10.21037/gs-23-428

Front Cardiovasc Med. 2024 Mar 27;11:1384637. doi: 10.3389/fcvm.2024.1384637. eCollection 2024.

ABSTRACT

The non-neuronal cholinergic system of the cardiovascular system has recently gained attention because of its origin. The final product of this system is acetylcholine (ACh) not derived from the parasympathetic nervous system but from cardiomyocytes, endothelial cells, and immune cells. Accordingly, it is defined as an ACh synthesis system by non-neuronal cells. This system plays a dispensable role in the heart and cardiomyocytes, which is confirmed by pharmacological and genetic studies using murine models, such as models with the deletion of vesicular ACh transporter gene and modulation of the choline acetyltransferase (ChAT) gene. In these models, this system sustained the physiological function of the heart, prevented the development of cardiac hypertrophy, and negatively regulated the cardiac metabolism and reactive oxygen species production, resulting in sustained cardiac homeostasis. Further, it regulated extra-cardiac organs, as revealed by heart-specific ChAT transgenic (hChAT tg) mice. They showed enhanced functions of the blood-brain barrier (BBB), indicating that the augmented system influences the BBB through the vagus nerve. Therefore, the non-neuronal cardiac cholinergic system indirectly influences brain function. This mini-review summarizes the critical cardiac phenotypes of hChAT tg mice and focuses on the effect of the system on BBB functions. We discuss the possibility that a cholinergic signal or vagus nerve influences the expression of BBB component proteins to consolidate the barrier, leading to the downregulation of inflammatory responses in the brain, and the modulation of cardiac dysfunction-related effects on the brain. This also discusses the possible interventions using the non-neuronal cardiac cholinergic system.

PMID:38601043 | PMC:PMC11004362 | DOI:10.3389/fcvm.2024.1384637

Am J Respir Cell Mol Biol. 2024 Apr 10. doi: 10.1165/rcmb.2023-0451OC. Online ahead of print.

ABSTRACT

Extreme heat caused by climate change is increasing transmission of infectious diseases resulting in a sharp rise in heat-related illness and mortality. Understanding mechanistic link between heat, inflammation and disease is thus important for public health. Thermal hyperpnea, and consequent respiratory alkalosis is crucial in febrile seizures and convulsions induced by heat stress in humans. Here we address what causes thermal hyperpnea in neonates and how is it affected by inflammation. TRPV1, a heat-activated channel is sensitized by inflammation and modulates breathing, and thus may play a key role. To investigate whether inflammatory sensitization of TRPV1 modifies neonatal ventilatory responses to heat stress, leading to respiratory alkalosis and an increased susceptibility to hyperthermic seizures we treated neonatal rats with bacterial lipopolysaccharide, and breathing, arterial pH, in-vitro vagus nerve activity, and seizure susceptibility were assessed during heat stress in the presence or absence of a TRPV1 antagonist (AMG-9810) or shRNA-mediated TRPV1 suppression. Lipopolysaccharide-induced inflammatory preconditioning lowered the threshold temperature and latency of hyperthermic seizures. This was accompanied by increased tidal volume, minute ventilation, expired CO2, and arterial pH (alkalosis). Lipopolysaccharide exposure also elevated vagal spiking and intracellular calcium levels in response to hyperthermia. TRPV1 inhibition with AMG-9810 or shRNA reduced the lipopolysaccharide-induced susceptibility to hyperthermic seizures and altered the breathing pattern to fast shallow breaths (tachypnea), making each breath less efficient and restoring arterial pH. These results indicate that inflammation exacerbates thermal hyperpnea-induced respiratory alkalosis associated with increased susceptibility to hyperthermic seizures, primarily mediated by TRPV1 localized to vagus neurons.

PMID:38597725 | DOI:10.1165/rcmb.2023-0451OC

Int J Surg. 2024 Apr 9. doi: 10.1097/JS9.0000000000001428. Online ahead of print.

NO ABSTRACT

PMID:38597401 | DOI:10.1097/JS9.0000000000001428

World J Surg Oncol. 2024 Apr 6;22(1):87. doi: 10.1186/s12957-024-03370-0.

ABSTRACT

BACKGROUND: To investigate the short-term and long-term outcomes of preserving the celiac branch of the vagus nerve during laparoscopic distal gastrectomy.

METHODS: A total of 149 patients with prospective diagnosis of gastric cancer who underwent laparoscopic-assisted distal gastrectomy (LADG) combined with Billroth-II anastomosis and D2 lymph node dissection between 2017 and 2018 were retrospectively analyzed. The patients were divided into the preserved LADG group (P-LADG, n = 56) and the resected LADG group (R-LADG, n = 93) according to whether the vagus nerve celiac branch was preserved. We selected 56 patients (P-LADG, n = 56) with preservation of the celiac branch of the vagus nerve and 56 patients (R-LADG, n = 56) with removal of the celiac branch of the vagus nerve by propensity-matched score method. Postoperative nutritional status, weight change, short-term and long-term postoperative complications, and gallstone formation were evaluated in both groups at 5 years of postoperative follow-up. The status of residual gastritis and bile reflux was assessed endoscopically at 12 months postoperatively.

RESULTS: The incidence of diarrhea at 5 years postoperatively was lower in the P-LADG group than in the R-LADG group (p < 0.05). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 3.389, 95% confidential interval = 1.143-10.049, p = 0.028). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 4.371, 95% confidential interval = 1.418-13.479, p = 0.010).

CONCLUSIONS: Preservation of the celiac branch of the vagus nerve in LADG reduced the incidence of postoperative diarrhea postoperatively in gastric cancer.

TRIAL REGISTRATION: This study was registered with the Ethics Committee of the First Affiliated Hospital of Dalian Medical University in 2014 under the registration number: LCKY2014-04(X).

PMID:38582834 | DOI:10.1186/s12957-024-03370-0

J Craniomaxillofac Surg. 2024 Mar 26:S1010-5182(24)00116-1. doi: 10.1016/j.jcms.2024.03.033. Online ahead of print.

ABSTRACT

The study purpose is to review the surgical approach and evaluate the results in cases of head and neck malignancies with internal carotid artery invasion. The anatomical site of the primary tumor varied including a fixed massive metastatic neck disease of an occult intraoral carcinoma of the right tonsil, a recurrent metastatic neck tumor after laryngectomy for glottic primary carcinoma and a metastatic malignant melanoma of an unknown primary origin. In all cases carotid artery was invaded and therefore resected. An extended Javid shunt was performed between common carotid artery (CCA) and internal carotid artery (ICA) followed by CCA grafting with an interposition saphenous vein graft. In one case the vagus nerve was also grafted with an interposition sural graft. The total patient number was three. By clinical examination, follow-up and duplex scanning, the patency of the carotid grafts, vascular and non-vascular complications, disease recurrence and survival were analysed. Additionally, there was a double metachronous reconstruction for recurrence, giving the opportunity to study the graft adoption and response to disease. Internal carotid artery invasion portends a poor prognosis. The results show that carotid artery resection followed by the appropriate reconstruction yields a chance for cure or can provide reasonable palliation.

PMID:38582678 | DOI:10.1016/j.jcms.2024.03.033

Auton Neurosci. 2024 Mar 29;253:103174. doi: 10.1016/j.autneu.2024.103174. Online ahead of print.

ABSTRACT

The liver is a large organ with crucial functions in metabolism and immune defense, as well as blood homeostasis and detoxification, and it is clearly in bidirectional communication with the brain and rest of the body via both neural and humoral pathways. A host of neural sensory mechanisms have been proposed, but in contrast to the gut-brain axis, details for both the exact site and molecular signaling steps of their peripheral transduction mechanisms are generally lacking. Similarly, knowledge about function-specific sensory and motor components of both vagal and spinal access pathways to the hepatic parenchyma is missing. Lack of progress largely owes to controversies regarding selectivity of vagal access pathways and extent of hepatocyte innervation. In contrast, there is considerable evidence for glucose sensors in the wall of the hepatic portal vein and their importance for glucose handling by the liver and the brain and the systemic response to hypoglycemia. As liver diseases are on the rise globally, and there are intriguing associations between liver diseases and mental illnesses, it will be important to further dissect and identify both neural and humoral pathways that mediate hepatocyte-specific signals to relevant brain areas. The question of whether and how sensations from the liver contribute to interoceptive self-awareness has not yet been explored.

PMID:38579493 | DOI:10.1016/j.autneu.2024.103174

World J Gastrointest Oncol. 2024 Mar 15;16(3):653-658. doi: 10.4251/wjgo.v16.i3.653.

ABSTRACT

Pylorus-preserving gastrectomy (PPG) has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer (EGC) with a distal tumor border at least 4 cm proximal to the pylorus. The procedure essentially preserves the function of the pyloric sphincter, which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 cm. The suprapyloric and infrapyloric vessels are usually preserved, as are the hepatic and pyloric branches of the vagus nerve. Compared with distal gastrectomy, PPG has significant advantages in preventing dumping syndrome, body weight loss and bile reflux gastritis. The postoperative complications after PPG have reached an acceptable level. PPG can be considered a safe, effective, and superior choice in EGC, and is expected to be extensively performed in the future.

PMID:38577445 | PMC:PMC10989389 | DOI:10.4251/wjgo.v16.i3.653