The Japanese Epidemiologic Study for Perioperative Anaphylaxis, a prospective nationwide study: allergen exposure, epidemiology, and diagnosis of anaphylaxis during general anaesthesia.

BACKGROUND: Diagnosis of perioperative anaphylaxis is often challenging. This study describes the utility of a newly developed tool for identifying patients with a high possibility of anaphylaxis, and aimed to investigate the frequency of anaphylaxis with each drug during the perioperative period in Japan. METHODS: This study included patients with anaphylaxis of Grade 2 or higher severity during general anaesthesia at 42 facilities across Japan in 2019 and 2020. We developed and adopted a unique objective evaluation tool yielding a composite score for diagnosing anaphylaxis, which includes the results of skin tests and basophil activation tests, and clinical scores for perioperative anaphylaxis. The number of cases using each drug and the total number of anaphylaxis cases were investigated to calculate the frequency of anaphylaxis. RESULTS: General anaesthesia was performed in 218 936 cases, which included 55 patients with suspected perioperative anaphylaxis. The developed composite score diagnosed 43 of them with a high probability of anaphylaxis. The causative agent was identified in 32 cases. Plasma histamine levels showed high diagnostic accuracy for anaphylaxis. The top causative agents were rocuronium (10 cases in 210 852 patients, 0.005%), sugammadex (7 cases in 150 629 patients, 0.005%), and cefazolin (7 cases in 106 005 patients, 0.007%). CONCLUSIONS: We developed a composite tool to diagnose anaphylaxis, and found that the combination of tryptase levels, skin testing, and basophil activation testing results and clinical score improved the certainty of anaphylaxis diagnosis. The incidence of perioperative anaphylaxis in our study was 1 in about 5000 general anaesthesia cases. CLINICAL TRIAL REGISTRATION: UMIN000035350.

In vitro and in vivo development of interspecies Asian elephant embryos reconstructed with pig enucleated oocytes.

Interspecies somatic cell nuclear transfer (iSCNT) has an immense potential to rescue endangered animals and extinct species like mammoths. In this study, we successfully established an Asian elephant's fibroblast cell lines from ear tissues, performed iSCNT with porcine oocytes and evaluated the in vitro and in vivo development of reconstructed embryos. A total of 7780 elephant-pig iSCNT embryos were successfully reconstructed and showed in vitro development with cleavage rate, 4-cell, 8-cell and blastocyst rate of 73.01, 30.48, 5.64, and 4.73%, respectively. The total number of elephant-pig blastocyte cells and diameter of hatched blastocyte was 38.67 and 252.75 µm, respectively. Next, we designed species-specific markers targeting EDNRB, AGRP and TYR genes to verify the genome of reconstructed embryos with donor nucleus/species. The results indicated that 53.2, 60.8, and 60.8% of reconstructed embryos (n = 235) contained elephant genome at 1-cell, 2-cell and 4-cell stages, respectively. However, the percentages decreased to 32.3 and 32.7% at 8-cell and blastocyst stages, respectively. Furthermore, we also evaluated the in vivo development of elephant-pig iSCNT cloned embryos and transferred 2260 reconstructed embryos into two surrogate gilts that successfully became pregnant and a total of 11 (1 and 10) fetuses were surgically recovered after 17 and 19 days of gestation, respectively. The crown-rump length and width of elephant-pig cloned fetuses were smaller than the control group. Unfortunately, none of these fetuses contained elephant genomes, which suggested that elephant embryos failed to develop in vivo. In conclusion, we successfully obtained elephant-pig reconstructed embryos for the first time and these embryos are able to develop to blastocyst, but the in vivo developmental failure needs further investigated.

Synergy by Ristocetin and CXCL12 in Human Platelet Activation: Divergent Regulation by Rho/Rho-Kinase and Rac.

CXCL12, belonging to the CXC chemokine family, is a weak agonist of platelet aggregation. We previously reported that the combination of CXCL12 and collagen at low doses synergistically activates platelets via not CXCR7 but CXCR4, a specific receptor for CXCL12 on the plasma membrane. Recently, we reported that not Rho/Rho kinase, but Rac is involved in the platelet aggregation induced by this combination. Ristocetin is an activator of the von Willebrand factor that interacts with glycoprotein (GP) Ib/IX/V, which generates thromboxane A2 via phospholipase A2 activation, resulting in the release of the soluble CD40 ligand (sCD40L) from human platelets. In the present study, we investigated the effects of a combination of ristocetin and CXCL12 at low doses on human platelet activation and its underlying mechanisms. Simultaneous stimulation with ristocetin and CXCL12 at subthreshold doses synergistically induce platelet aggregation. A monoclonal antibody against not CXCR7 but CXCR4 suppressed platelet aggregation induced by the combination of ristocetin and CXCL12 at low doses. This combination induces a transient increase in the levels of both GTP-binding Rho and Rac, followed by an increase in phosphorylated cofilin. The ristocetin and CXCL12-induced platelet aggregation as well as the sCD40L release were remarkably enhanced by Y27362, an inhibitor of Rho-kinase, but reduced by NSC23766, an inhibitor of the Rac-guanine nucleotide exchange factor interaction. These results strongly suggest that the combination of ristocetin and CXCL12 at low doses synergistically induces human platelet activation via Rac and that this activation is negatively regulated by the simultaneous activation of Rho/Rho-kinase.

A practical guide for perioperative smoking cessation.

The perioperative management of patients who are smokers presents anesthesiologists with various challenges related to respiratory, circulatory, and other clinical problems. Regarding 30-day postoperative outcomes, smokers have higher risks of mortality and complications than non-smokers, including death, pneumonia, unplanned tracheal intubation, mechanical ventilation, cardiac arrest, myocardial infarction, and stroke. Given the benefits of smoking cessation and the adverse effects of smoking on perioperative patient management, patients should quit smoking long before surgery. However, anesthesiologists cannot address these issues alone. The Japanese Society of Anesthesiologists established guidelines in 2015 (published in a medical journal in 2017) to enlighten surgical staff members and patients regarding perioperative tobacco cessation. The primary objective of perioperative smoking cessation is to reduce the risks of adverse cardiovascular and respiratory events, wound infection, and other perioperative complications. Perioperative preparations constitute a powerful teachable moment, a "golden opportunity" for smoking cessation to achieve improved primary disease outcomes and prevent the occurrence of tobacco-related conditions. This review updates the aforementioned guidelines as a practical guide to cover the nuts and bolts of perioperative smoking cessation. Its goal is to assist surgeons, anesthesiologists, and other medical professionals and to increase patients' awareness of smoking risks before elective surgery.

Duloxetine suppresses BMP-4-induced release of osteoprotegerin via inhibition of the SMAD signaling pathway in osteoblasts.

Duloxetine, a selective serotonin-norepinephrine reuptake inhibitor, is currently recommended for the treatment of chronic painful disorders such as fibromyalgia, chronic musculoskeletal pain, and diabetic peripheral neuropathy. We previously demonstrated that bone morphogenetic protein-4 (BMP-4) stimulates osteoprotegerin (OPG) production in osteoblast-like MC3T3-E1 cells, and that p70 S6 kinase positively regulates OPG synthesis. The present study aimed to investigate the effect of duloxetine on BMP-4-stimulated OPG synthesis in these cells. Duloxetine dose-dependently suppressed OPG release stimulated by BMP-4. Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), reduced BMP-4-stimulated OPG release, whereas a selective and specific norepinephrine reuptake inhibitor, reboxetine, failed to affect OPG release. In addition, another SSRI sertraline also inhibited BMP-4-stimulated OPG release. On the other hand, siRNA of SMAD1 reduced the OPG release stimulated by BMP-4, indicating the involvement of the SMAD1/5/8 pathway in OPG release. Rapamycin inhibited BMP-4-stimulated p70 S6 kinase phosphorylation, and compound C suppressed the SMAD1/5/8 phosphorylation stimulated by BMP-4. Duloxetine did not affect BMP-4-induced phosphorylation of p70 S6 kinase but suppressed SMAD1/5/8 phosphorylation. Both fluvoxamine and sertraline also inhibited BMP-4-elicited phosphorylation of SMAD1/5/8. These results strongly suggest that duloxetine suppresses BMP-4-stimulated OPG release via inhibition of the Smad1/5/8 signaling pathway in osteoblasts.

A Comparison of the Required Bronchial Cuff Volume Obtained by 2 Cuff Inflation Methods, Capnogram Waveform-Guided Versus Pressure-Guided: A Prospective Randomized Controlled Study.

BACKGROUND: Double-lumen endobronchial tubes (DLTs) are used for one-lung ventilation (OLV) during thoracic surgery. Overinflation into the bronchial cuff causes damage to the tracheobronchial mucosa, whereas underinflation leads to an incomplete collapse of the nonventilated lung or incomplete ventilation of the ventilated lung. However, how to determine the appropriate bronchial cuff volume and pressure during OLV is unclear. The objective of this study is to compare the required bronchial cuff volume for lung separation obtained by 2 different cuff inflation methods under closed- and open-chest conditions. METHODS: A total of 64 patients scheduled to undergo elective thoracic surgery requiring OLV were recruited. Left DLTs were used for both right- and left-sided surgery. The patients were randomly assigned to 1 of 2 inflation-type groups to estimate the bronchial cuff volume. In the capnogram waveform-guided bronchial cuff inflation group (capno group, n = 27), the bronchial cuff was inflated until a capnometer sampling gas containing CO2 from the nonventilated lung displayed a flat line. The corresponding bronchial cuff volume and pressure were then recorded. In the pressure-guided bronchial cuff inflation group (pressure group, n = 29), the bronchial cuff was inflated by a cuff inflator to a pressure of 20 cm H2O. Lung separation was confirmed when a flat line of a capnometer was observed after gas sampling from the nonventilated lung. RESULTS: Under closed-chest conditions, the bronchial cuff sealing volume for the capno group was significantly lower than that for the pressure group (mean [standard deviation {SD}], 1.00 [0.65] mL vs 1.44 [0.59] mL, mean difference, -0.44; 97.5% confidence interval [CI], -0.78 to -0.11; P = .010). Under open-chest conditions, the bronchial cuff sealing volume for the capno group was also significantly lower than that for the pressure group (mean [SD], 0.65 [0.66] mL vs 1.22 [0.45] mL, mean difference, -0.58; 97.5% CI, -0.88 to -0.27; P < .001). CONCLUSIONS: The lowest cuff volume providing an air-tight bronchial seal was obtained by the capnogram waveform-guided bronchial cuff inflation method. Since the cuff volume required to achieve an air-tight seal decreases after opening the chest, readjustment of the bronchial cuff volume to prevent bronchial cuff damage to the tracheobronchial mucosa after opening the chest may be advisable.

HSP90 inhibitors strengthen extracellular ATP-stimulated synthesis of interleukin-6 in osteoblasts: Amplification of p38 MAP kinase.

Heat shock protein 90 (HSP90) is expressed ubiquitously in a variety of cell types including osteoblasts. HSP90 acts as a key driver of proteostasis under pathophysiological conditions. Here, we investigated the involvement of HSP90 in extracellular ATP-stimulated interleukin (IL)-6 synthesis and HSP90 downstream signalling in osteoblast-like MC3T3-E1 cells. In osteoblasts, extracellular ATP stimulates the synthesis of IL-6, a bone-remodelling agent. Geldanamycin, 17-allylamino-17-demethoxy-geldanamycin (17-AAG) and onalespib, three different HSP90 inhibitors, amplified the ATP-stimulated IL-6 release. Geldanamycin increased IL-6 mRNA expression elicited by ATP. ATP enhanced the triiodothyronine-induced osteocalcin release, but HSP90 inhibitors suppressed the release. Extracellular ATP induced the phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK), p38 MAPK, c-Jun N-terminal kinase (JNK), p70 S6 kinase, Akt, and myosin phosphatase-targeting subunit (MYPT), a Rho-kinase substrate. SB203580, an inhibitor of p38 MAPK, suppressed ATP-stimulated IL-6 release. Inhibitors of MEK1/2 (PD98059), JNK (SP600125), upstream kinase of p70 S6 kinase (rapamycin) and Akt (deguelin), all increased IL-6 release. Y27632, a Rho-kinase inhibitor, failed to affect the IL-6 release stimulated by ATP. Geldanamycin and 17-AAG both amplified ATP-induced p38 MAPK phosphorylation, although geldanamycin inhibited the phosphorylation of Akt induced by ATP. In addition, SB203580 significantly reduced the amplification by geldanamycin of the IL-6 release. Taken together, our results strongly suggest that HSP90 inhibitors up-regulate extracellular ATP-stimulated IL-6 synthesis via amplification of p38 MAPK activation in osteoblasts. SIGNIFICANCE OF THE STUDY: Heat shock protein 90 (HSP90) acts as a key driver of proteostasis under pathophysiological conditions in a variety of cell types. We have previously shown that HSP90 is expressed at high levels in osteoblast-like MC3T3-E1 cells, even in their quiescent state, consistent with HSP90 performing an important physiological function in osteoblasts. In the present study, we investigated whether HSP90 is implicated in extracellular ATP-induced interleukin (IL)-6 synthesis in osteoblast-like MC3T3-E1 cells. Our results strongly suggest that HSP90 inhibitors up-regulate extracellular ATP-stimulated IL-6 synthesis via amplification of p38 mitogen-activated protein kinase activation in osteoblasts.

Duloxetine strengthens osteoblast activation by prostaglandin E1: Upregulation of p38 MAP kinase.

Duloxetine, a serotonin-norepinephrine reuptake inhibitor, is currently recommended as a useful medicine to chronic pain including low back pain. However, as the analogy of classical selective serotonin reuptake inhibitors, there is a concern to deteriorate osteoporosis with remaining to clarify the exact mechanism of duloxetine in bone metabolism. We have previously reported that prostaglandin E1 (PGE1) induces the synthesis of both osteoprotegerin (OPG) and interleukin-6 (IL-6), essential regulators of bone metabolism, in osteoblast-like MC3T3-E1 cells. Based upon them, we herein investigated the mechanism whereby the effect of duloxetine on the synthesis of OPG and IL-6 induced by PGE1 in these cells. Duloxetine enhanced the release from MC3T3-E1 cells of both OPG and IL-6 stimulated by PGE1. However, reboxetine, a selective and specific inhibitor of norepinephrine reuptake, failed to affect the PGE1-induced release of OPG or IL-6. Oppositely, fluvoxamine and sertraline, agents belonging to the class of selective serotonin reuptake inhibitor, upregulated the PGE1-stimulated release of both OPG and IL-6. Duloxetine amplified the expression of OPG mRNA and IL-6 mRNA stimulated by PGE1. Duloxetine strengthened the PGE1-induced p38 MAP kinase phosphorylation, which was amplified by fluvoxamine as well. SB203880, an inhibitor of p38 MAP kinase, suppressed the amplifying effects by duloxetine or fluvoxamine on the PGE1-stimulated release of OPG and IL-6. These results strongly suggest that duloxetine could strengthen osteoblast activation by PGE1 through the upregulation of p38 MAP kinase, leading to increasing the synthesis of OPG and IL-6.

Olive polyphenol reduces the collagen-elicited release of phosphorylated HSP27 from human platelets.

Hydroxytyrosol (HT) and oleuropein (OLE) are natural polyphenols found in extra virgin olive oil. Accumulating evidence indicates that ingestion of olive oil contributes to reduce the risk of cardiovascular diseases and stroke. It has been reported that HT and OLE inhibit human platelet aggregation. We have shown that collagen induces the phosphorylation of heat shock protein 27 (HSP27) in human platelets, resulting in the release of HSP27, an extracellular pro-inflammatory agent. In this study, we investigated the effects of HT and OLE on the collagen-stimulated human platelet activation. The PDGF-AB secretion and the soluble CD40 ligand (sCD40L) release by collagen were reduced by HT or OLE. HT and OLE significantly suppressed the phosphorylation of HSP27 and the release of phosphorylated-HSP27. These findings suggest that olive polyphenol reduces the collagen-stimulated phosphorylation of HSP27 in human platelets and the release. Our results may provide a novel anti- inflammatory effect of olive polyphenol.

Enhancement by HSP90 inhibitor of PGD2-stimulated HSP27 induction in osteoblasts: Suppression of SAPK/JNK and p38 MAP kinase.

Heat shock protein (HSP) 90 that is ubiquitously expressed in various tissues is a major molecular chaperone. We have previously demonstrated that prostaglandin D2 (PGD2), a bone remodeling factor, elicits the expression of HSP27, a small HSP, through stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and p38 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the involvement of HSP90 in the PGD2-stimulated HSP27 induction and the underlying mechanism in MC3T3-E1 cells. Onalespib, an inhibitor of HSP90, significantly enhanced the PGD2-stimulated HSP27 induction. In addition, geldanamycin, another HSP90 inhibitor, potentiated the HSP27 induction. Both onalespib and geldanamycin markedly amplified the PGD2-induced phosphorylation of SAPK/JNK and p38 MAP kinase. SP600125, an inhibitor of SAPK/JNK, and SB203580, an inhibitor of p38 MAP kinase, suppressed the amplification by onalespib of the PGD2-stimulated HSP27 induction. These results strongly suggest that HSP90 plays a negative role in the HSP27 induction stimulated by PGD2 in osteoblasts, and that the inhibitory effect of HSP90 is mediated through the regulation of SAPK/JNK and p38 MAP kinase.

Endothelium-dependent vasodilation in the cerebral arterioles of rats deteriorates during acute hyperglycemia and then is restored by reducing the glucose level.

PURPOSE: Acute hyperglycemia in patients with traumatic brain injury correlates with a poor neurological outcome. We investigated the endothelium function of rat cerebral arterioles during acute hyperglycemia and after reducing the glucose levels using insulin. We also examined whether or not oxidative stress was involved in the cerebral arteriole response to acute hyperglycemia. METHODS: In isoflurane-anesthetized, mechanically ventilated rats, we used closed cranial window preparation to measure the changes in the pial arteriolar diameter following the topical application of acetylcholine (ACh) or adenosine. We examined the pial arteriolar vasodilator response before hyperglycemia, during hyperglycemia, and after reducing the glucose level using insulin. After intravenous pretreatment with an NADPH oxidase inhibitor (apocynin or diphenylene iodonium), we reexamined the pial arteriolar vasodilator response following the topical application of ACh. RESULTS: Under control conditions, the topical application of ACh dose-dependently dilated the cerebral arterioles. The vasodilatory responses to topical ACh were impaired during hyperglycemia and improved after the administration of insulin. The vasodilatory responses to topical adenosine were not affected by the glucose levels. In the apocynin or diphenylene iodonium pretreatment group, the topical application of ACh dilated the cerebral arterioles during hyperglycemia. CONCLUSION: Acute hyperglycemia induces a dysfunction of the endothelium-dependent vasodilation of rat cerebral arterioles. The dysfunction can be reversed by improving the acute hyperglycemia and it can be prevented entirely by the administration of NADPH oxidase inhibitors. These results could suggest that controlling the glucose levels works protectivity to endothelium function of cerebral arterioles.

[Plain X-ray or Computed Tomography Image of Epidural Catheters with Various Materials].

BACKGROUND: Although breakage of the epidural catheter inside patients is a rare complication, plain X-ray or computed tomography (CT) image is useful for diagnosis of catheter remnant However, it is not well known whether the catheter materials are visible in these images. METHODS: We examined 3 types of X-ray permeabil- ity catheters and 6 types of X-ray impermeability cath- eters available in Japan. We obtained plain X-ray images of catheters alone, plain X-ray images of cathe- ters with bone dummy and CT images of catheters in the model of epidural space. RESULTS: On plain X-ray images of catheters alone, we could confirm all 6 types of X-ray impermeability catheters. However, on plain X-ray images of catheters with bone dummy, we could confirm only 3 types of catheters among 6 X-ray impermeability catheters. On CT images, we could confirm all 6 types of X-ray impermeability catheters, but not X-ray permeability catheters. CONCLUSIONS: Plain X-ray image can not provide the detection for some X-ray impermeability catheters. CT image is useful- for diagnosis of X-ray impermeability catheters.

Effect of Postoperative Administration of Pregabalin for Post-thoracotomy Pain: A Randomized Study.

OBJECTIVE: The present study was performed to evaluate the effect of postoperative administration of pregabalin in patients who reported moderate-to-severe pain after epidural analgesia following thoracotomy. DESIGN: An open-label, randomized, controlled, parallel-group study. SETTING: A single center in Japan. PARTICIPANTS: Consecutive patients (aged≥20 years) who reported moderate-to-severe pain after effectual 2-day epidural analgesia post-thoracotomy for lung cancer from February 2012 to March 2013. INTERVENTIONS: Patients were assigned to 2 groups: control (control treatment: acetaminophen, 400 mg, and codeine phosphate powder, 20 mg) or pregabalin (pregabalin, 75 mg, plus control treatment). The 12-week study period included 2-week study treatment and 10-week follow-up. MEASUREMENTS AND MAIN RESULTS: For efficacy, the primary endpoint was the visual analog scale (VAS) scores for pain at rest and with coughing at week 2, and secondary endpoints were the VAS scores for pain and the neuropathic pain questionnaire at week 12. Fifty patients were randomized (25 per group). At week 2, the VAS scores for pain at rest (mean [SD]) were 29.5 (21.9) in the control group and 16.3 (15) in the pregabalin group (p = 0.02); for pain with coughing, the scores were 45.2 (20.9) and 28.8 (25.9), respectively (p = 0.02). VAS scores improved more in the pregabalin group than in the control group over the 12 weeks. Patients free from possible neuropathic pain were 48% of the control group and 88% of the pregabalin group, respectively (p = 0.001). CONCLUSIONS: Postoperative administration of pregabalin effectively reduced post-thoracotomy pain.

Effects of topical and intravenous JM-1232(-) infusion on cerebrovascular reactivity in rats.

A novel short-acting benzodiazepine receptor agonist, JM-1232(-), has been shown to have a sedative/hypnotic effect and wide safety margin. However, its effect on cerebral vessels is not well known. Therefore, we investigated the cerebrovascular reactivity to topical and intravenous JM-1232(-) and during hypotension or hypercapnia with intravenous administration of JM-1232(-). We used a closed cranial window preparation to measure the changes of cerebral pial arteriolar diameters in isoflurane-anesthetized Sprague-Dawley rats. We first measured the direct effect of topical JM-1232(-). We then determined the effect of intravenous JM-1232(-) and then we measured the response to hypercapnia before and after JM-1232(-) infusion. Finally, we measured the reaction to stepwise induction of hypotension before and after JM-1232(-) infusion. Topical infusion of JM-1232(-) dilated pial arterioles. Intravenous infusion of JM-1232(-) changed pial arterioles by 4.5 ± 2.7 %, 5.0 ± 3.9 %, and -2.8 ± 2.6 % (at 0.1, 0.3, and 1.0 mg/kg/min, respectively). Hypercapnia dilated pial arterioles before and after JM-1232(-) infusion. The diameters of pial arterioles did not change during hypotension before or after intravenous JM-1232(-) infusion. These results indicate that topical JM-1232(-) has a dilative effect on pial arterioles and that intravenous administration of JM-1232(-) may not affect cerebrovascular reactivity to hypotension or hypercapnia.

Differential effects of intravenous anesthetics on PDGF-BB-induced vascular smooth muscle cell migration.

BACKGROUND: Intravenous anesthetics are used during the perioperative and/or postoperative period in critically ill patients. Vascular smooth muscle cells (VSMCs) play important roles in vascular injury repair or restenosis after intervention. We previously reported that platelet-derived growth factor (PDGF)-BB induces VSMC migration via extracellular signal-regulated kinase (ERK) and Akt in a VSMC line, A10 cells. In the present study, we investigated the effects of intravenous anesthetics on PDGF-BB-induced VSMC migration and the mechanism. METHODS: VSMCs migration was assessed using Boyden chamber, and phosphorylation of each protein kinase was analyzed by Western blotting. RESULTS: Propofol or midazolam but not ketamine or dexmedetomidine suppressed PDGF-BB-induced A10 cells migration in a concentration-dependent manner. The suppressive effects on migration were observed also in human aortic smooth muscle cells. Propofol or midazolam did not affect phosphorylation of PDGF receptor ß in A10 cells. Propofol or midazolam failed to affect PDGF-BB-induced phosphorylation of ERK or Akt. On the other hand, propofol or midazolam attenuated PDGF-BB-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), but did not affect phosphorylation of stress-activated protein kinase/c-Jun N-terminal kinase. Both ketamine and dexmedetomidine had no effect on the phosphorylation of p38 MAPK induced by PDGF-BB. CONCLUSION: These results strongly suggest that propofol or midazolam inhibits VSMC migration by PDGF-BB via suppression of p38 MAPK activation. Propofol or midazolam may affect VSMC function in critically ill patients.

Adenosine monophosphate-activated protein kinase regulates platelet-derived growth factor-BB-induced vascular smooth muscle cell migration.

Migration of vascular smooth muscle cells (VSMCs) is essential for repair of vascular injury, development of atherosclerotic lesions and restenosis after angioplasty or by-pass graft surgery. It has been reported that platelet-derived growth factor (PDGF)-BB induces VSMC migration via the p44/p42 mitogen-activated protein (MAP) kinase pathway and the phosphatidylinositol 3 (PI3)-kinase/Akt pathway. Adenosine monophosphate-activated protein kinase (AMPK) is generally known to regulate multiple metabolic pathway. In the present study, we investigated the involvement of AMPK in PDGF-BB-induced migration of VSMCs using, a VSMC line, A10 cells. PDGF-BB induced phosphorylation of AMPK-α at Thr-172 residue. Treatment of A10 cells with compound C, an AMPK inhibitor, suppressed PDGF-BB-induced migration in a concentration-dependent manner (0.01-1µM). Compound C truly attenuated PDGF-BB induced phosphorylation of acetyl-CoA carboxylase, a downstream substance of AMPK. Downregulation of AMPK-α expression by the siRNA appeared an anti-migratory effect on PDGF-BB-induced migration. PDGF-BB-induced phosphorylation of c-Raf, MEK1/2 or p44/p42 MAP kinase, and phosphorylation of PI3-kinase or Akt were markedly suppressed by compound C. In conclusion, our results strongly suggest that PDGF-BB induces activation of AMPK in VSMCs, and subsequently regulates the migration via both the p44/p42 MAP kinase pathway and the PI3-kinase/Akt pathway.

Successful treatment with spinal cord stimulation for pain due to eosinophilic granulomatosis with polyangiitis: a case report.

BACKGROUND: Although most patients of eosinophilic granulomatosis with polyangiitis (EGPA) experience a reduction in pain within several weeks to months of the initiation of immunotherapies, some suffer from residual neuropathic symptoms for a long time. CASE PRESENTATION: A 28-year-old woman diagnosed with EGPA visited. She had been treated with steroid pulse therapy, intravenous immunoglobulin, and mepolizumab (antiinterleukin-5 agent). Her symptoms other than peripheral neuropathy improved, but posterior lower thigh pain and weakness of the lower legs worsened. At the initial visit, she used crutches and complained of numb pain in both posterior lower thighs, especially the left one. She also presented with left foot drop and reported a decreased tactile sensation on the lateral sides of both lower thighs. We performed spinal cord stimulation (SCS) at the L1 level on both sides. Her pain remarkably decreased, her tactile sensation improved, her muscle strength increased, and she was able to walk without crutches. CONCLUSIONS: We herein report the first case of lower extremity pain being successfully treated with SCS in an EGPA patient who did not respond well to drug therapy. Because the cause of pain in EGPA is neuropathy induced by vasculitis, there is ample ability for SCS to improve this pain. When pain is neuropathic, whatever the cause, SCS may be worth trying, even for pain from disorders other than EGPA.

Tramadol regulates the activation of human platelets via Rac but not Rho/Rho-kinase.

Tramadol is a useful analgesic which acts as a serotonin and noradrenaline reuptake inhibitor in addition to µ-opioid receptor agonist. Cytoplasmic serotonin modulates the small GTPase activity through serotonylation, which is closely related to the human platelet activation. We recently reported that the combination of subthreshold collagen and CXCL12 synergistically activates human platelets. We herein investigated the effect and the mechanism of tramadol on the synergistic effect. Tramadol attenuated the synergistically stimulated platelet aggregation (300 µM of tramadol, 64.3% decrease, p<0.05). Not morphine or reboxetine, but duloxetine, fluvoxamine and sertraline attenuated the synergistic effect of the combination on the platelet aggregation (30 µM of fluvoxamine, 67.3% decrease, p<0.05; 30 µM of sertraline, 67.8% decrease, p<0.05). The geranylgeranyltransferase inhibitor GGTI-286 attenuated the aggregation of synergistically stimulated platelet (50 µM of GGTI-286, 80.8% decrease, p<0.05), in which GTP-binding Rac was increased. The Rac1-GEF interaction inhibitor NSC23766 suppressed the platelet activation and the phosphorylation of p38 MAPK and HSP27 induced by the combination of collagen and CXCL12. Tramadol and fluvoxamine almost completely attenuated the levels of GTP-binding Rac and the phosphorylation of both p38 MAPK and HSP27 stimulated by the combination. Suppression of the platelet aggregation after the duloxetine administration was observed in 2 of 5 patients in pain clinic. These results suggest that tramadol negatively regulates the combination of subthreshold collagen and CXCL12-induced platelet activation via Rac upstream of p38 MAPK.

Preventive effect of varenicline on impairment of endothelial function in cerebral vessels induced by acute smoking in rats.

Preoperative smoking cessation is important for recovery from surgery without complications. Available evidence suggests nicotine replacement therapy could be safe and effective in the perioperative period. On the other hand, the newly developed selective nicotinic acetylcholine (ACh) receptor partial agonist, varenicline tartrate, is also effective as an aid for smoking cessation and helps people to stop smoking. During the transitional phase between the decision to stop smoking and actual smoking cessation, patients could use varenicline before undertaking smoking cessation. We have previously reported that acute cigarette smoking can cause impairment of endothelium-dependent vasodilation in cerebral vessels; thus, the use of varenicline before surgery in a patient who is still a smoker may not be safe with regard to endothelial function. Therefore, to assess the safety of varenicline in terms of endothelial function, we evaluated its effect on the acute smoking-induced impairment of endothelium-dependent cerebral vasodilation. In anesthetized Sprague-Dawley rats, we applied ACh topically to pial vessels; then, after administering intravenous varenicline or saline injection, we reexamined the ACh-induced vasodilator response both before and after smoking. Under control conditions, cerebral pial arterioles were dose-relatedly dilated by ACh. After smoking, 10(-5) M ACh constricted the arterioles following saline pretreatment (diameter -7.6 ± 1.8 %, n = 6), but induced dilation following varenicline pretreatment (diameter +15.3 ± 3.3 %, n = 6). Thus, varenicline may prevent the smoking-induced impairment of endothelium-dependent vasodilation in cerebral pial arterioles.