Trend and survival outcome in Taiwan cervical cancer patients: A population-based study.

Cervical cancer is one of the most common cancers in Taiwan. The aim of this study was to estimate the incidence of cervical cancer in Taiwan, the relationship between cervical cancer and previous co-morbidities, and the long-term trend of cervical cancer mortality differences in the rest of the world.This study was based on the data of cervical cancer in the National Health Insurance Research Database from 1997 to 2013, and estimated the annual prevalence and incidence of cervical cancer. Joinpoint regression analysis was used to obtain the percentage of annual incidence of cervical cancer, morbidity and survival of patients with cervical cancer by statistical regression analysis.The average annual percentage change (APC) was -7.2, indicating a decrease in the incidence of cervical cancer during the study period. The 1-year, 2-year, and 5-year mortality rates of cervical cancer are relatively stable. The average APC of mortality was higher in high Charlson comorbidity index (CCI) group.This study found that both of prevalence and incidence of cervical cancer descend in Taiwan. The incidence of cervical cancer in Taiwan is increasing with age. The sample survival rate was stable in cervical cancer patients during the study period.

IL-17 deficiency attenuates acetaminophen-induced hepatotoxicity in mice.

Acetaminophen (APAP) overdose results in the production of reactive oxygen species (ROS), hepatocyte necrosis, and cell death, and leads to acute liver failure. Interleukin-17 (IL-17), a pro-inflammatory cytokine, plays a key role in the recruitment of neutrophils into sites of inflammation and subsequent damage after liver ischemia-reperfusion injury. In this study, we employed IL-17 knockout (KO) mice to investigate the role of IL-17 in APAP-induced hepatotoxicity. IL-17 wide type (WT) and IL-17 KO mice received an intraperitoneal injection of APAP (300 mg/kg). After 16 h of treatment, the hepatic injury, inflammatory mediators, immune cell infiltration, and western blotting were examined and analyzed. The serum alanine transferase (ALT) enzyme levels and hepatic myeloperoxidase (MPO) activity were significantly elevated 16 h after APAP treatment in the WT mice. IL-17 deficiency significantly attenuates APAP-induced liver injury, MPO activity, pro-inflammatory cytokines (tumor necrosis factor-α, IL-6 and interferon-γ) levels and inflammatory cell (neutrophils, macrophage) infiltration in the liver. Moreover, phosphorylated extracellular signal-regulated kinase (ERK) was significantly decreased at 16 h after APAP treatment in the IL-17 KO mice compared with the IL-17 WT mice. Our data suggests that IL-17 plays a pivotal role in APAP-induced hepatotoxicity through modulation of inflammatory response, and perhaps in part through the ERK signaling pathway. Blockade of IL-17 could be a potential therapeutic target for APAP-induced hepatotoxicity.

Video laryngoscopy-assisted tracheal intubation in airway management.

INTRODUCTION: Video laryngoscopy-assisted tracheal intubation devices have become alternatives to traditional laryngoscopes in recent years. This review will provide information on commonly used video laryngoscopes and their clinical applications in airway management. AREAS COVERED: In this review, the differences between video laryngoscopy and direct laryngoscopy, and the utilization of video laryngoscopes in specific clinical settings are discussed. EXPERT COMMENTARY: Video laryngoscopy should be embraced as an initial approach to intubation in patients with suspected difficult airway. Acute care providers should be familiar with more than one intubation techniques so that a rescue attempt can be applied promptly. Continual practice and familiarity with new video laryngoscopes are still essential to maximize the effectiveness and minimize the complications of using these devices.

Tropisetron Protects Against Acetaminophen-Induced Liver Injury via Suppressing Hepatic Oxidative Stress and Modulating the Activation of JNK/ERK MAPK Pathways.

Objectives. To investigate the protective effects of tropisetron on acetaminophen- (APAP-) induced liver injury in a mice model. Methods. C57BL/6 male mice were given tropisetron (0.3 to 10 mg/kg) 30 minutes before a hepatotoxic dose of acetaminophen (300 mg/kg) intraperitoneally. Twenty hours after APAP intoxication, sera alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, hepatic myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) activities, and liver histopathological changes were examined. The MAP kinases were also detected by western blotting. Results. Our results showed that tropisetron pretreatment significantly attenuated the acute elevations of the liver enzyme ALT level, hepatic MPO activity, and hepatocytes necrosis in a dose-dependent manner (0.3-10 mg/kg) in APAP-induced hepatotoxicity mice. Tropisetron (1 and 3 mg/kg) suppressed APAP-induced hepatic lipid peroxidation expression and alleviated GSH and SOD depletion. Administration of tropisetron also attenuated the phosphorylation of c-Jun-NH2-terminal protein kinase (JNK) and extracellular signal-regulated kinase (ERK) caused by APAP. Conclusion. Our data demonstrated that tropisetron's hepatoprotective effect was in part correlated with the antioxidant, which were mediated via JNK and ERK pathways on acetaminophen-induced liver injury in mice.

Minocycline, a microglial inhibitor, blocks spinal CCL2-induced heat hyperalgesia and augmentation of glutamatergic transmission in substantia gelatinosa neurons.

BACKGROUND: Several lines of evidence suggest that CCL2 could initiate the hyperalgesia of neuropathic pain by causing central sensitization of spinal dorsal horn neurons and facilitating nociceptive transmission in the spinal dorsal horn. The cellular and molecular mechanisms by which CCL2 enhances spinal pain transmission and causes hyperalgesia remain unknown. The substantia gelatinosa (lamina II) of the spinal dorsal horn plays a critical role in nociceptive transmission. An activated spinal microglia, which is believed to release pro-inflammatory cytokines including TNF-α, plays an important role in the development of neuropathic pain, and CCL2 is a key mediator for spinal microglia activation. In the present study, we tested the hypothesis that spinal CCL2 causes the central sensitization of substantia gelatinosa neurons and enhances spinal nociceptive transmission by activating the spinal microglia and augmenting glutamatergic transmission in lamina II neurons. METHODS: CCL2 was intrathecally administered to 2-month-old male rats. An intrathecal injection of CCL2 induced heat hyperalgesia, which was assessed using the hot plate test. Whole-cell voltage-clamp recordings substantia gelatinosa neurons in spinal cord slices were performed to record glutamatergic excitatory postsynaptic currents (EPSCs) and GABAergic inhibitory postsynaptic currents (IPSCs). RESULTS: The hot plate test showed that 1 day after the intrathecal injection of CCL2 (1 µg), the latency of hind-paw withdrawal caused by a heat stimulus was significantly reduced in rats. One day after the intrathecal administration of CCL2, the amplitude of the evoked glutamatergic EPSCs and the frequency of spontaneous glutamatergic miniature EPSCs (mEPSCs) were significantly increased in outer lamina II neurons. Intrathecal co-injection of minocycline, a specific inhibitor of microglial activation, and CCL2 blocked the CCL2-induced reduction in the latency of hind-paw withdrawal and thermal hyperalgesia. Following intrathecal co-administration of CCL2 and minocycline, CCL2 failed to increase the frequency of glutamatergic mEPSCs and failed to promote glutamine release in lamina II neurons. Intrathecal co-injection of WP9QY, a selective TNF-α antagonist, and CCL2 completely inhibited CCL2-induced heat hyperalgesia and inhibited the increase in the frequency of glutamatergic mEPSCs in substantia gelatinosa neurons. CONCLUSION: In summary, our results suggest that an intrathecal injection of CCL2 causes thermal hyperalgesia by augmenting the excitatory glutamatergic transmission in substantia gelatinosa neurons through a presynaptic mechanism and facilitating nociceptive transmission in the spinal dorsal horn. Further studies show that intrathecal co-administration of minocycline, a specific inhibitor of microglial activation, or WP9QY, a selective TNF-α antagonist, completely inhibited CCL2 potentiation of glutamatergic transmission in substantia gelatinosa neurons and CCL2-induced heat hyperalgesia. The results of the present study suggest that peripheral nerve injury-induced upregulation of the spinal CCL2 level causes the central sensitization of substantia gelatinosa neurons by activating spinal microglia and that TNF-α mediates CCL2-induced thermal hyperalgesia and augmentation of glutamatergic transmission in lamina II neurons.

CC chemokine ligand 2 upregulates the current density and expression of TRPV1 channels and Nav1.8 sodium channels in dorsal root ganglion neurons.

BACKGROUND: Inflammation or nerve injury-induced upregulation and release of chemokine CC chemokine ligand 2 (CCL2) within the dorsal root ganglion (DRG) is believed to enhance the activity of DRG nociceptive neurons and cause hyperalgesia. Transient receptor potential vanilloid receptor 1 (TRPV1) and tetrodotoxin (TTX)-resistant Na(v)1.8 sodium channels play an essential role in regulating the excitability and pain transmission of DRG nociceptive neurons. We therefore tested the hypothesis that CCL2 causes peripheral sensitization of nociceptive DRG neurons by upregulating the function and expression of TRPV1 and Nav1.8 channels. METHODS: DRG neuronal culture was prepared from 3-week-old Sprague-Dawley rats and incubated with various concentrations of CCL2 for 24 to 36 hours. Whole-cell voltage-clamp recordings were performed to record TRPV1 agonist capsaicin-evoked inward currents or TTX-insensitive Na(+) currents from control or CCL2-treated small DRG sensory neurons. The CCL2 effect on the mRNA expression of TRPV1 or Na(v)1.8 was measured by real-time quantitative RT-PCR assay. RESULTS: Pretreatment of CCL2 for 24 to 36 hours dose-dependently (EC(50) value = 0.6 ± 0.05 nM) increased the density of capsaicin-induced currents in small putative DRG nociceptive neurons. TRPV1 mRNA expression was greatly upregulated in DRG neurons preincubated with 5 nM CCL2. Pretreating small DRG sensory neurons with CCL2 also increased the density of TTX-resistant Na(+) currents with a concentration-dependent manner (EC(50) value = 0.7 ± 0.06 nM). The Na(v)1.8 mRNA level was significantly increased in DRG neurons pretreated with CCL2. In contrast, CCL2 preincubation failed to affect the mRNA level of TTX-resistant Nav1.9. In the presence of the specific phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 or Akt inhibitor IV, CCL2 pretreatment failed to increase the current density of capsaicin-evoked inward currents or TTX-insensitive Na(+) currents and the mRNA level of TRPV1 or Na(v)1.8. CONCLUSIONS: Our results showed that CCL2 increased the function and mRNA level of TRPV1 channels and Na(v)1.8 sodium channels in small DRG sensory neurons via activating the PI3K/Akt signaling pathway. These findings suggest that following tissue inflammation or peripheral nerve injury, upregulation and release of CCL2 within the DRG could facilitate pain transmission mediated by nociceptive DRG neurons and could induce hyperalgesia by upregulating the expression and function of TRPV1 and Na(v)1.8 channels in DRG nociceptive neurons.

Astringinin-mediated attenuation of the hepatic injury following trauma-hemorrhage.

Although astringinin administration under adverse circulatory conditions is known to be protective, the mechanism by which astringinin produces the salutary effects remains unknown. We hypothesize that astringinin administration in males following trauma-hemorrhage decreases cytokine production and protects against hepatic injury. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure: 40 mmHg for 90 min, then resuscitation). Different doses of astringinin (0.01, 0.03, 0.1, 0.3 mg/kg of body weight) or vehicle were administered intravenously during resuscitation. Concentrations of plasma aspartate aminotransferase (AST) with alanine aminotransferase (ALT) and various hepatic parameters were measured (n = 8 rats/group) at 24 h after resuscitation. One-way ANOVA and Tukey testing were used for statistical analysis. Trauma-hemorrhage significantly increased plasma AST and ALT levels at 24 h postresuscitation; there was a dose-related benefit when astringinin was administered at doses of 0.01 to 0.3 mg/kg. In astringinin-treated (0.3 mg/kg) rats subjected to trauma-hemorrhage, there were significant improvements in liver myeloperoxidase (MPO) activity (237.80 +/- 45.89 vs. 495.95 +/- 70.64 U/mg protein, P < 0.05), interleukin-6 (IL-6) levels (218.54 +/- 34.52 vs. 478.60 +/- 76.21 pg/mg protein, P < 0.05), cytokine-induced neutrophil chemoattractant (CINC)-1 (88.32 +/- 20.33 vs. 200.70 +/- 32.68 pg/mg protein, P < 0.05), CINC-3 (110.83 +/- 26.63 vs. 290.14 +/- 76.82 pg/mg protein, P < 0.05) and intercellular adhesion molecule (ICAM)-1 concentrations (1,868.5 +/- 211.5 vs. 3,645.0 +/- 709.2 pg/mg protein, P < 0.05), as well as in histology. Results show that astringinin significantly attenuates proinflammatory responses and hepatic injury after trauma-hemorrhage. In conclusion, the salutary effects of astringinin administration on attenuation of hepatic injury following trauma-hemorrhage are likely due to reduction of pro-inflammatory mediator levels.

The effect of warmed ropivacaine to body temperature on epidural sensory block characteristics.

STUDY OBJECTIVE: To determine whether warmed (body temperature) ropivacaine increases the speed of onset of sensory block of epidural anesthesia. STUDY DESIGN: Prospective, randomized, double-blind study. SETTING: University hospital. PATIENTS: 180 ASA physical status I and II patients, aged 18 to 64 years, undergoing elective anal surgery. INTERVENTIONS: Patients were randomly divided into 6 groups defined by ropivacaine temperature [room temperature (RT) or body temperature (BT)] and concentration (0.5%, 0.75%, or 1.0%). MEASUREMENTS: Sensory block was evaluated by pinprick at the T10, T12, L3, and the perianal region (S4, S5) dermatomes. pH values and adverse events were also recorded. MAIN RESULTS: There were no differences in baseline demographics, pH, or upper sensory level between groups. Mean onset time of T12 and L3 sensory block was significantly faster for each BT than RT ropivacaine concentration. Anal region (S4, S5) sensory block was significantly faster after BT 0.75% versus RT 0.75% ropivacaine. CONCLUSIONS: Warmed ropivacaine shortens the onset of sensory block of epidural anesthesia.

Effect of warm lidocaine on the sensory onset of epidural anesthesia: a randomized trial.

BACKGROUND: Administration of local anesthetics at body temperature has been reported to shorten the onset time of regional block; however, studies examining the effects of warmed lidocaine on the onset of epidural anesthesia are limited. Here, we ascertain whether warming lidocaine solution to body temperature shortens the time to onset of epidural anesthesia. METHODS: Eighty patients were randomly allocated into two groups of equal size. Both received 16 ml of lidocaine solution injected via the epidural route at the L4- 5 interspace, with one group receiving the solution at room temperature (RT, 18 degrees Celsius) and the other receiving the solution warmed to body temperature (BT, 36 degrees Celsius). Sensory blocks at the T10, T12, and L3 dermatomes, perianal region, and upper level dermatomes were assessed by pinprick and their onset times recorded. Patients with incomplete anal sensory block were excluded. RESULTS: Seventy-seven patients were included for analysis. The pH value of the local anesthetic solution was significantly increased at BT compared to RT (6.57 +/- 0.11 vs. 6.47 +/- 0.11, p < 0.05). Significantly shorter onset times of sensory block were observed at the T12 (10.03 +/- 3.55 vs. 11.71 +/- 3.76 min) and L3 (7.49 +/- 3.19 vs. 9.92 +/- 3.46 min) dermatomes for the BT compared to the RT group (p < 0.005). The onset time of sensory block at the anal region was also shorter in the BT than the RT group (11.54 +/- 4.35 vs. 12.50 +/- 4.06 min, p < 0.05). No differences between groups with respect to gender, age, height, weight, visual analogue pain score, upper sensory level, or adverse events were observed. CONCLUSIONS: Administration of lidocaine at BT compared to RT shortens the onset time of sensory block in epidural anesthesia with no associated adverse effects.

Nocistatin and nociceptin exert opposite effects on the excitability of central amygdala nucleus-periaqueductal gray projection neurons.

Central amygdala nucleus (CeA)-periaqueductal gray (PAG) pathway is the component of descending antinociceptive circuitry. Nociceptin/orphanin FQ (N/OFQ) and nocistatin (NST) produce supraspinal pronociceptive and antinociceptive effects, respectively. We hypothesized that opposite effects of N/OFQ and NST on supraspinal pain modulation result from their opposing effects on the excitability of CeA-PAG projection neurons. This hypothesis was tested by investigating electrophysiological effects of N/OFQ and NST on medial CeA neurons that project to PAG (CeA(M)-PAG). N/OFQ hyperpolarized CeA(M)-PAG projection neurons by enhancing inwardly rectifying potassium conductance. In contrast, NST depolarized CeA(M)-PAG neurons by causing the opening of TRPC cation channels via G(alphaq/11)-PLC-PKC pathway. CeA(M)-PAG neurons hyperpolarized by N/OFQ express CRF or neurotensin mRNA. NST-responsive CeA(M)-PAG neurons contain CRF or substance P mRNA. Our study provides the evidence that the molecular and cellular basis for opposite effects of N/OFQ and NST on supraspinal pain regulation is their opposing effects on the excitability of peptidergic CeA(M)-PAG neurons.

Acute unilateral parotid glands enlargement following endotracheal general anesthesia: report of two cases.

Acute parotid gland enlargement in association with general anesthesia is rare and has also been called anesthesia mumps. We present two patients who were scheduled for lumbar spine surgery under general anesthesia. Each developed acute unilateral parotid gland enlargement over one side of the face proven by sonography. Case 1: A 52-year-old man was scheduled for his third lumbar spine to first sacral spine surgery for scoliosis and spondylolisthesis. The patient was provided general anesthesia with oral endotracheal intubation and placed in the prone position with the neck flexed at approximately 10 degrees. The head was turned to the left side and the right side of the face was placed on a soft gel rolling pad. After 6 hours of surgery, swelling of the right parotid gland was noted upon endotracheal extubation. Twenty four hours later, the patient received sonographic examination of the salivary gland which showed dilatation of the right parotid duct with obstructive inflammation. After receiving non-steroidal anti-inflammatory drug (NSAID) treatment, his symptoms and signs subsided 2 weeks after the surgery. Case 2: A 53-year-old woman was scheduled for her third lumbar spine to fifth lumbar spine instrumentation and internal fixations for spondylolisthesis. A similar anesthetic regimen and surgical position was provided as with Case 1. The duration of the surgery was about 5 hours and swelling of the right parotid gland was also noted postoperatively. Sonographic examination of the salivary gland showed only an inflammatory process without dilatation of the parotid duct. She had complete recovery of the condition 10 days after surgery. There were no complications nor residual enlargement of the parotid gland in either of our two patients after conservative treatment.

PINK1 mutants associated with recessive Parkinson's disease are defective in inhibiting mitochondrial release of cytochrome c.

Mutations in PTEN-induced kinase 1 (PINK1) gene cause recessive familial type 6 of Parkinson's disease (PARK6). We investigated molecular mechanisms underlying PINK1 neuroprotective function and PARK6 mutation-induced loss of PINK1 function. Overexpression of wild-type PINK1 blocked mitochondrial release of apoptogenic cytochrome c, caspase-3 activation and apoptotic cell death induced by proteasome inhibitor MG132. N-terminal truncated PINK1 (NDelta35), which lacks mitochondrial localization sequence, did not block MG132-induced cytochrome c release and cytotoxicity. Despite mitochondrial expression, PARK6 mutant (E240K), (H271Q), (G309D), (L347P), (E417G) and C-terminal truncated (CDelta145) PINK1 failed to inhibit MG132-induced cytochrome c release and caspase-3 activation. Overexpression of wild-type PINK1 blocked cytochrome c release and cell death caused by atractyloside, which opens mitochondrial permeability transition pore (mPTP). PARK6 PINK1 mutants failed to inhibit atractyloside-induced cytochrome c release. These results suggest that PINK1 exerts anti-apoptotic effect by inhibiting the opening of mPTP and that PARK6 mutant PINK1 loses its ability to prevent mPTP opening and cytochrome c release.

Polyglutamine-expanded ataxin-7 decreases nuclear translocation of NF-kappaB p65 and impairs NF-kappaB activity by inhibiting proteasome activity of cerebellar neurons.

Our recent study indicated that polyglutamine-expanded ataxin-7-Q75 induced apoptotic death of cultured cerebellar neurons by downregulating Bcl-x(L) expression and activating mitochondrial apoptotic cascade. Mutant polyglutamine-expanded proteins are believed to impair the proteolytic function of ubiquitin-proteasome system by sequestering components of proteasomes. Proteasome degradation of IkappaBalpha permits nuclear translocation of NF-kappaB and is required for continuous NF-kappaB activity, which supports the survival of cultured cerebellar neurons by inducing Bcl-x(L) expression. Thus, we tested the hypothesis that mutant ataxin-7-Q75 causes proteasome dysfunction and impairs NF-kappaB activity, leading to reduced Bcl-x(L) expression, caspase activation and cerebellar neuronal death. EMSA assays indicate that DNA-binding activity of NF-kappaB was significantly decreased in cerebellar neurons expressing ataxin-7-Q75. Similar to mutant ataxin-7-Q75, NF-kappaB inhibitor APEQ induced cerebellar neuronal death by decreasing Bcl-x(L) expression and activating caspase-9. Mutant ataxin-7-Q75 inhibited the proteolytic activity of proteasomes in cerebellar neurons. Proteasome inhibitor MG132 also caused cerebellar neuronal death by decreasing Bcl-x(L) expression and activating caspase-9. Both ataxin-7-Q75 and MG132 caused the cytosolic accumulation of IkappaBalpha in cerebellar neurons. Mutant ataxin-7-Q75 or MG132 increased the cytosolic level of NF-kappaB p65 and decreased the nuclear NF-kappaB p65 level. Our study provides the evidence that polyglutamine-expanded ataxin-7-Q75 decreases nuclear translocation of NF-kappaB p65 and impairs NF-kappaB activity by inhibiting proteasome activity of cerebellar neurons.

Polyglutamine-expanded ataxin-7 activates mitochondrial apoptotic pathway of cerebellar neurons by upregulating Bax and downregulating Bcl-x(L).

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant neurodegenerative disorder caused by polyglutamine-expanded ataxin-7. In the present investigation, we expressed disease-causing mutant ataxin-7-Q75 in the primary neuronal culture of cerebellum with the aid of recombinant adenoviruses. Subsequently, this in vitro cellular model of SCA7 was used to study the molecular mechanism by which mutant ataxin-7-Q75 induces neuronal death. TUNEL staining studies indicated that polyglutamine-expanded ataxin-7-Q75 caused apoptotic cell death of cultured cerebellar neurons. Mutant ataxin-7-Q75 induced the formation of active caspase-3 and caspase-9 without activating caspase-8. Polyglutamine-expanded ataxin-7-Q75 promoted the release of apoptogenic cytochrome-c and Smac from mitochondria, which was preceded by the downregulation of Bcl-x(L) protein and upregulation of Bax protein expression in cultured cerebellar neurons. Further real-time TaqMan RT-PCR assays showed that mutant ataxin-7-Q75 upregulated Bax mRNA level and downregulated Bcl-x(L) mRNA expression in the primary neuronal culture of cerebellum. The present study provides the evidence that polyglutamine-expanded ataxin-7-Q75 activates mitochondria-mediated apoptotic cascade and induces neuronal death by upregulating Bax expression and downregulating Bcl-x(L) expression of cerebellar neurons.

Two C-terminal amino acids, Ser(334) and Ser(335), are required for homologous desensitization and agonist-induced phosphorylation of opioid receptor-like 1 receptors.

Various cellular signaling pathways induced by nociceptin activation of ORL1 (opioid receptor-like 1 receptor) develop homologous desensitization. Multiple lines of evidence suggest that agonist-induced phosphorylation of serine (Ser)/threonine (Thr) residues at intracellular carboxyl tail leads to homologous desensitization of G protein-coupled receptors. In the present study, we investigated the functional role played by C-terminal Ser/Thr residues in agonist-induced desensitization and phosphorylation of ORL1. In HEK 293 cells expressing wild-type ORL1 and ORL1(CDelta21), which lacks C-terminal 21 amino acids, nociceptin inhibition of adenylate cyclase activity exhibited homologous desensitization after 1 h pretreatment of nociceptin. In contrast, ORL1(CDelta34), which differs with ORL1(CDelta21) by lacking C-terminal Ser(334), Ser(335) and Ser(343) residues, failed to develop agonist-induced desensitization. Point mutant (S343A) ORL1 underwent homologous desensitization after nociceptin pretreatment. Substituting Ser(334) or Ser(335) with alanine greatly impaired nociceptin-induced ORL1 desensitization. In HEK 293 cells expressing double mutant (S334A/S335A) ORL1, nociceptin pretreatment failed to significantly affect the efficacy and potency by which nociceptin inhibits forskolin-stimulated cAMP formation. Mutation of Ser(334) and Ser(335) also greatly reduced nociceptin-induced ORL1 phosphorylation. These results suggest that two C-terminal serine residues, Ser(334) and Ser(335), are required for homologous desensitization and agonist-induced phosphorylation of ORL1.

Efficacy of ultrasound-guided axillary brachial plexus block: a comparative study with nerve stimulator-guided method.

BACKGROUND: The aim of this study was to compare the efficacy of axillary brachial plexus block using an ultrasound-guided method with the nerve stimulator-guided method. We also compared the efficacy of ultrasound-guided single-injection with those of double-injection for the quality of the block. METHODS: Ninety patients scheduled for surgery of the forearm or hand were randomly allocated into three groups (n = 30 per group), i.e., nerve stimulator-guided and double-injection (ND) group, ultrasound-guided and double-injection (UD) group, and ultrasound-guided and single-injection (US) group. Each patient received 0.5 ml kg(-1) of 1.5% lidocaine with 5 mg kg(-1) epinephrine. Patients in the ND group received half the volume of lidocaine injected near the median and radial nerves after identification using a nerve stimulator. Patients in the UD group received half the volume of lidocaine injected around the lateral and medial aspects of the axillary artery, while those in the US group were given the entire volume near the lateral aspect of the axillary artery. The extent of the sensory blockade of the seven nerves and motor blockades of the four nerves were assessed 40 min after the performance of axillary brachial plexus block. RESULTS: Seventy percent of the patients in the ND and US groups as well as 73% of the patients in the UD group obtained satisfactory sensory and motor blockades. The success rate of performing the block was 90% in patients in the ND and UD groups and 70% in the US group. The incidence of adverse events was significantly higher in the ND group (20%) compared with that in the US group and the UD group (0%; p = 0.03). CONCLUSIONS: Ultrasound-guided axillary brachial plexus block, using either single- or double-injection technique, provided excellent sensory and motor blockades with fewer adverse events.

Heterodimerization of opioid receptor-like 1 and mu-opioid receptors impairs the potency of micro receptor agonist.

Nociceptin activation of ORL1 (opioid receptor-like 1 receptor) has been shown to antagonize mu receptor-mediated analgesia at the supraspinal level. ORL1 and mu-opioid receptor (muR) are co-expressed in several subpopulations of CNS neurons involved in regulating pain transmission. The amino acid sequence of ORL1 also shares a high degree of homology with that of mu receptor. Thus, it is hypothesized that ORL1 and muR interact to form the heterodimer and that ORL1/muR heterodimerization may be one molecular basis for ORL1-mediated antiopioid effects in the brain. To test this hypothesis, myc-tagged ORL1 and HA-tagged muR are co-expressed in human embryonic kidney (HEK) 293 cells. Co-immunoprecipitation experiments demonstrate that ORL1 dimerizes with muR and that intracellular C-terminal tails of ORL1 and muR are required for the formation of ORL1/muR heterodimer. Second messenger assays further indicate that formation of ORL1/muR heterodimer selectively induces cross-desensitization of muR and impairs the potency by which [D-Ala(2),N-methyl-Phe(4),Gly-ol(5)]enkephalin (DAMGO) inhibits adenylate cyclase and stimulates p42/p44 mitogen-activated protein kinase (MAPK) phosphorylation. These results provide the evidence that ORL1/muR heterodimerization and the resulting impairment of mu receptor-activated signaling pathways may contribute to ORL1-mediated antiopioid effects in the brain.

Glutamate transporter function of rat hippocampal astrocytes is impaired following the global ischemia.

Astroglial glutamate transporters, GLT-1 and GLAST, play an essential role in removing released glutamate from the extracellular space and are essential for maintaining a low concentration of extracellular glutamate in the brain. It was hypothesized that impaired function of glial glutamate transporters induced by transient global ischemia may lead to an elevated level of extracellular glutamate and subsequent excitotoxic neuronal death. To test this hypothesis, in the present study, we performed whole-cell patch-clamp recording of hippocampal CA1 astrocytes in control or postischemic slices, and measured glutamate transporter activity by recording glutamate-evoked transporter currents. Six to 24 h after global ischemia, maximal amplitude of glutamate transporter currents recorded from postischemic CA1 astrocytes was significantly reduced. Western blotting analysis indicated that transient global ischemia decreased the protein level of GLT-1 in the hippocampal CA1 area without affecting GLAST protein level. Further real-time quantitative RT-PCR assays showed that global ischemia resulted in a decrease in GLT-1 mRNA level of hippocampal CA1 region. Global ischemia-induced reduction in GLT-1 expression and glutamate transporter function of CA1 astrocytes precedes the initiation of delayed neuronal death in CA1 pyramidal layer. The present study provides the evidence that transient global ischemia downregulates glutamate transporter function of hippocampal CA1 astrocytes by decreasing mRNA and protein levels of GLT-1.

Reproducible hepatic dysfunction following separate anesthesia with sevoflurane and desflurane.

Both desflurane and sevoflurane have individually been reported to induce hepatic dysfunction; however hepatic dysfunction after administration of both of them separately in a single patient has not previously been reported. As their metabolites differ in nature, we considered that it would be unlikely that their combined use would cause sensitization and induce hepatic dysfunction. We report on the first patient with reproducible liver dysfunction after sevoflurane and desflurane. This 54-year-old man sequentially received 3 anesthetics over a 1-year period. The first anesthetic was isoflurane, and the course was uneventful. The second anesthetic was sevoflurane, and this resulted in fever with chills and elevated aspartate aminotransferase (543 U/l) 17 days later. The third anesthetic was desflurane which resulted in a similar clinical picture after 17 days. The symptoms improved, and the serum transaminase level returned to normal after conservative therapy. The similar time interval between the operation date and the onset of hepatic dysfunction, after excluding other possibilities, made us highly suspicious that the hepatic dysfunction was induced by sevoflurane on 1 occasion and desflurane on the other. We suggest that inhaled anesthetics should be totally replaced by intravenous anesthetics for future operations in patients with such a diagnosis.

Functional analysis of connexin-26 mutants associated with hereditary recessive deafness.

The physiological importance of connexin-26 (Cx26) gap junctions in regulating auditory function is indicated by the finding that autosomal recessive DFNB1 deafness is associated with mutations of the Cx26 gene. To investigate the pathogenic role of Cx26 mutation in recessive hearing loss, four putative DFNB1 Cx26 mutants (V84L, V95M, R127H, and R143W) were stably expressed in N2A cells, a communication-deficient cell line. In N2A cells expressing (R127H) Cx26 gap junctions, macroscopic junctional conductance and ability of transferring neurobiotin between transfected cells were greatly reduced. Despite the formation of defective junctional channels, immunoreactivity of (R127H) Cx26 was mainly localized in the cell membrane and prominent in the region of cell-cell contact. Mutant (V84L), (V95M), or (R143W) Cx26 protein formed gap junctions with a junctional conductance similar to that of wild-type Cx26 junctional channels. (V84L), (V95M), or (R143W) Cx26 gap junctions also permitted neurobiotin transfer between pairs of transfected N2A cells. The present study suggests that (R127H) mutation associated with hereditary sensorineural deafness results in the formation of defective Cx26 gap junctions, which may lead to the malfunction of cochlear gap junctions and hearing loss. Further studies are required to determine the exact mechanism by which mutant (V84L), (V95M), and (R143W) Cx26 proteins, which are capable of forming functional homotypic junctional channels in N2A cells, cause the cochlear dysfunction and sensorineural deafness.