FcγR/ROS/CK2α Is the Key Inducer of NF-κB Activation in a Murine Model of Asthma.

BACKGROUND: The transcription factor nuclear factor (NF)-κB plays a pivotal role in the development of allergic airway inflammation. However, the mechanism of NF-κB activation in asthma remains to be elucidated. METHODS: CK2α activation was assessed by CK2α phosphorylation and protein expression. Airway levels of histamine and cytokines were determined by ELISA. We used 2 (active and passive) forms of allergic pulmonary inflammation models. In the active form, the animals were immunized with ovalbumin (OVA) intraperitoneally, followed by an airway challenge with OVA. In the passive form, the animals were passively sensitized by intratracheal instillation with either anti-OVA IgE or anti-OVA IgG, followed by an airway challenge with OVA. The role of NADPH oxidase (NOX) in CK2α activation was assessed using NOX2-/- and NOX4-/- mice because NOX2 and NOX4 contribute to many inflammatory diseases. RESULTS: The second airway challenge increased CK2α phosphorylation and protein expression in airway epithelial cells as well as nuclear translocation of the p50 and p65 subunits of NF-κB, all of which were inhibited by the CK2α inhibitor 4,5,6,7-tetrabromobenzotriazole and the antioxidant N-acetyl-L-cysteine. CK2α phosphorylation and protein expression were significantly impaired in NOX2-/-, but not in NOX4-/-, mice. Induction of passive sensitization using anti-OVA IgE activated neither CK2α nor NF-κB. In contrast, induction of passive sensitization using anti-OVA IgG activated both CK2α and NF-κB. CONCLUSIONS: These data suggest that Fcγ receptor/reactive oxygen species/CK2α is a key inducer of NF-κB activation in airway epithelial cells in a murine model of asthma.

Glutamine Prevents Late-Phase Anaphylaxis via MAPK Phosphatase 1-Dependent Cytosolic Phospholipase A2 Deactivation.

BACKGROUND: Cytosolic phospholipase A2 (cPLA2) plays a key role in the development of late-phase anaphylaxis. L-Glutamine (Gln), a nonessential amino acid, has anti-inflammatory activity via inhibiting cPLA2. METHODS: We used a penicillin-induced murine model of anaphylaxis, and late-phase anaphylaxis was quantified by measuring the increase in the hematocrit (Ht) value. Various inhibitors, small interfering RNA, and knockout mice were used in inhibition experiments. Phosphorylation and protein expression of cPLA2, ERK, and MAPK phosphatase 1 (MKP-1) were detected by Western blotting. RESULTS: Leukotriene (LT) B4 was found to be another potent inducer of late-phase anaphylaxis besides the known mediator platelet-activating-factor (PAF). Gln efficiently prevented late-phase anaphylaxis when it was administered up to 3 h after challenge injection via inhibiting cPLA2. Inhibition studies indicated that p38 MAPK was the major upstream regulator of cPLA2. Gln dephosphorylated p38 and cPLA2 via up-regulating the negative regulator of p38 MAPK, i.e., MKP-1 protein. MKP-1 blockade abrogated all the effects of Gln. CONCLUSION: Of the cPLA2 metabolites, PAF and LTB4 play a key role in the development of late-phase anaphylaxis, and Gln prevents the reaction via MKP-1-dependent deactivation of cPLA2.

Platelet-activating factor enhances tumour metastasis via the reactive oxygen species-dependent protein kinase casein kinase 2-mediated nuclear factor-κB activation.

Platelet-activating factor (PAF) promotes tumour metastasis via activation of the transcription factor nuclear factor-κB (NF-κB). We here investigated the role of the protein kinase CK2 (formerly Casein Kinase 2 or II) in PAF-induced NF-κB activation and tumour metastasis, given that PAF has been reported to increase CK2 activity, and that CK2 plays a key role in NF-κB activation. PAF increased CK2 activity, phosphorylation and protein expression in vivo as well as in vitro. CK2 inhibitors inhibited the PAF-mediated NF-κB activation and expression of NF-κB-dependent pro-inflammatory cytokines and anti-apoptotic factors. Pre-treatment with the antioxidant N-Acetyl-L-Cysteine (NAC) resulted in a significant inhibition in PAF-induced enhancement of CK2 activity, phosphorylation and protein expression in vivo as well as in vitro. H2 O2 and known reactive oxygen species inducers, lipopolysaccharide (LPS) and tumour necrosis factor-α (TNF-α) enhanced CK2 activity, phosphorylation and protein expression, which was again inhibited by antioxidant. PAF, LPS and TNF-α induced increased CK2 activity, phosphorylationand protein expression, which were inhibited by p38 inhibitor. PAF, LPS or TNF-α increased pulmonary metastasis of B16F10, which was inhibited by antioxidants, CK2 inhibitor and p38 inhibitor. Our data suggest that (i) reactive oxygen species activate CK2 via p38, which, in turn, induces NF-κB activation, and (ii) PAF, LPS and TNF-α increase pulmonary tumour metastasis via the induction of the reactive oxygen species (ROS)/p38/CK2/NF-κB pathway.

Glutamine suppresses airway neutrophilia by blocking cytosolic phospholipase A(2) via an induction of MAPK phosphatase-1.

Neutrophils are inflammatory cells that may contribute in a crucial way to the pathophysiology of steroid-resistant severe asthma. We previously reported that the nonessential amino acid l-glutamine (Gln) suppressed the recruitment of neutrophils into the airway in a murine model of asthma. In this study, we investigated the mechanisms by which Gln exerts beneficial effects in airway neutrophilia. We used the model we previously developed, which is suitable for examining sequential early asthmatic events, including neutrophil infiltration. Gln suppressed airway neutrophilia in a CXC chemokine-independent way. Airway neutrophilia was associated with cytosolic phospholipase A(2) (cPLA(2)) and 5-lipoxygenase (5-LO) activities. p38 MAPK, the upstream pathway of cPLA(2) and 5-LO, played a key role in inducing airway neutrophilia. Gln inhibited not only the phosphorylation of cPLA(2) and p38 MAPK but also leukotriene B(4) levels in the airways. Gln induced the early induction of MAPK phosphatase-1 (MKP-1) protein, a negative regulator of p38. MKP-1 small interfering RNA abrogated all the effects of Gln. Our results suggest that pathways involving p38/cPLA(2)/5-LO have a major role in airway neutrophilia. Gln suppresses airway neutrophilia via inhibiting p38 MAPK and its downstream pathways in an MKP-1-dependent way, which may provide a novel therapeutic strategy for pulmonary neutrophilic inflammatory diseases.

Biphasic late airway hyperresponsiveness in a murine model of asthma.

BACKGROUND: Nonspecific airway hyperresponsiveness (AHR) is one of the cardinal features of bronchial asthma. Early AHR is caused by chemical mediators released from pulmonary mast cells activated in an IgE-dependent way. However, the mechanism of late AHR remains unclear. METHODS: Features of airway allergic inflammation were analyzed, including antigen-induced AHR, using a murine model of asthma. The model was suitable for examining the sequential early molecular events occurring after the initial airway exposure to antigen. RESULTS: AHR increased at 10-12 h after airway challenge, followed by the second-phase response, which was larger and broader in resistance at 18-30 h. Pretreatment of sensitized animals with anti-tumor necrosis factor (TNF) before airway challenge or induction of allergic asthma in TNF(-/-) mice resulted in abrogation of the first-phase late AHR. Intratracheal instillation of TNF induced a single peak of AHR at 10 h. IgE and IgG immune complexes induced the development of the first-phase late AHR by TNF production. Pretreatment with cytosolic phospholipase inhibitor and 5-lipoxygenase inhibitors abolished the first-phase late AHR as well as the leukotriene B(4) levels in the airway. CpG-oligodeoxynucleotide (ODN) pretreatment reduced airway levels of Th2 cytokines, eosinophil infiltration and second-phase late AHR. However, CpG-ODN did not reduce TNF levels or the magnitude of first-phase late AHR. CONCLUSION: Biphasic late AHR occurs in a murine model of asthma. First- and second-phase late AHR is caused by TNF and Th2 response, respectively.

Chest anteroposterior diameter affects difficulty of laryngoscopy for non-morbidly obese patients.

PURPOSE: This prospective, observational study was performed to examine the hypothesis that if conventional 7-cm head elevation is applied, laryngoscopy is more difficult for patients with anteroposterior chest diameter (chest AP diameter) outside the average range (≥17.7 or ≤14.7 cm). METHODS: Chest AP diameter at the sternal notch were measured preoperatively. All patients were placed on a surgical bed with an incompressible 7-cm pillow. During laryngoscopy, the laryngeal view was graded by use of the Cormack-Lehane classification. Difficult visualization of the larynx (DVL) was defined as a grade 3 or 4 view. RESULTS: DVL was observed for 49 patients (18.2 %). Differences between measured chest AP diameter for each patient and the calculated median value were used for statistical analysis. In univariate analysis, the difference between chest AP diameter and the median value was significantly related to DVL. Logistic regression analysis confirmed that the difference between chest AP diameter and the median value was an independent predictor of DVL (odds ratio, 3.900; 95 % confidence interval, 2.371-6.415; p < 0.001). Receiver operating characteristic curve analysis showed that this test with a test threshold of 1.5 cm had reasonable diagnostic accuracy (area under the curve of 0.748). CONCLUSION: When using a standard pillow size of 7 cm, chest AP diameter above or below the average range (≥17.7 or ≤14.7 cm) was a strong predictor of DVL for apparently normal-sized patients. In such cases, modification of pillow height should be considered.

IgG immune complex induces the recruitment of inflammatory cells into the airway and TNF-mediated late airway hyperresponsiveness via NF-κB activation in mice.

BACKGROUND: Many of the inflammatory proteins that are expressed in asthmatic airways are regulated, at least partially, by nuclear factor (NF)-κB. Blockade of NF-κB activity has resulted in attenuation of the cardinal features of asthma. Thus, delineating the mechanisms involved in NF-κB activation in asthma might provide an interesting approach to improving the management of asthma. However, despite its importance, the mechanism for NF-κB activation in asthma has not yet been determined. OBJECTIVE: To examine the role of IgE and IgG antibodies (Abs) in the activation of NF-κB in mouse lungs. METHODS: To examine the effect of IgE, mice underwent intratracheal (i.t.) instillation of an IgE immune complex (IgE-IC) (anti-2,4-dinitrophenyl hapten (DNP) IgE + DNP-BSA or DNP-OVA) and anaphylactogenic anti-IgE (LO-ME-2). For IgG, mice underwent i.t. instillation with a complex of anti-chicken gamma globulin (CGG) IgG1 mAb + CGG. NF-κB activation was determined by gel shift assay. Small interfering RNA was used for blockade of p50 expression. The effect of tumor necrosis factor (TNF) blockade was determined using anti-TNF Ab. A previously established murine model of asthma was used to assess airway hyperresponsiveness (AHR). RESULTS: A single i.t. instillation of either IgE-IC or LO-ME-2 failed to induce activation of NF-κB in the lungs. In contrast, single i.t. instillation of IgG-IC was capable of inducing NF-κB activation, as well as NF-κB-dependent proinflammatory molecules, such as TNF and CXC chemokines. Pretreatment of p50 small interfering RNA decreased bronchoalveolar lavage fluid levels of TNF and macrophage inflammatory protein-2 induced by IgG-IC instillation. Single i.t. instillation of IgG-IC caused the recruitment of neutrophils and macrophages into the airway and TNF-mediated late AHR, but failed to induce Th2 cell-mediated asthmatic phenotypes. CONCLUSION: IgG, but not IgE, is the major Ab that induces not only NF-κB activation and NF-κB-dependent proinflammatory molecules in the lungs but also subsequent recruitment of inflammatory cells into the airway and TNF-mediated late AHR.

An evaluation of perioperative pregabalin for prevention and attenuation of postoperative shoulder pain after laparoscopic cholecystectomy.

Postlaparoscopic shoulder pain (PLSP) frequently follows laparoscopic surgery. In this placebo-controlled study, we evaluated the efficacy of two perioperative doses of pregabalin 300 mg 12 h apart for preventing and attenuating PLSP after laparoscopic cholecystectomy. The frequency and severity of PLSP, need for postoperative rescue analgesia, and side effect profiles were assessed for 48 h postoperatively. In both groups, the overall incidence of PLSP did not differ significantly, and the pain score for PLSP, time to first rescue analgesia, and cumulative ketorolac consumption were similar at each timepoint. However, the 2-h postoperative incidence of oversedation was higher with pregabalin.

Tumor necrosis factor-alpha develops late anaphylactic reaction through cytosolic phospholipase A(2) activation.

BACKGROUND: We have recently reported that tumor necrosis factor (TNF)-alpha plays an important role in the development of a late anaphylactic reaction, but the downstream pathway beyond TNF-alpha remains unclear. OBJECTIVE: It was the aim of this study to examine whether TNF-alpha induces late-phase anaphylaxis via the activation of cytosolic phospholipase A(2) (cPLA(2)). METHODS: Using a murine model of active systemic anaphylaxis to penicillin V, the induction of the late phase of anaphylaxis was quantified by measuring the increase in hematocrit value as well as the plasma level of platelet-activating factor in TNF-alpha knockout mice. Phosphorylation of mitogen-activated protein kinases (MAPKs) and cPLA(2) was measured by immunoprecipitation. cPLA(2) activity was assessed by using 1-stearoyl-2-[1-(14)C] arachidonyl-sn-glycero-3-phosphocholine as the substrate. RESULTS: Phosphorylation and enzymatic activity of cPLA(2), and phosphorylation of the 3 known MAPKs, i.e. p38, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase, were markedly increased in a TNF-alpha-dependent way in the lungs of mice undergoing anaphylaxis. A specific cPLA(2) inhibitor significantly attenuated the late anaphylactic symptoms. Either p38 or an ERK inhibitor significantly attenuated not only cPLA(2) phosphorylation and activity, but also the late-phase anaphylaxis. CONCLUSION: TNF-alpha-induces cPLA(2) activation through the pathway involving p38 MAPK and ERK activation and appears to be the key mechanism leading to the development of late-phase anaphylaxis.

GPCR Kinase (GRK)-2 Is a Key Negative Regulator of Itch: l-Glutamine Attenuates Itch via a Rapid Induction of GRK2 in an ERK-Dependent Way.

Many itch mediators activate GPCR and trigger itch via activation of GPCR-mediated signaling pathways. GPCRs are desensitized by GPCR kinases (GRKs). The aim of this study is to explore the role of GRKs in itch response and the link between GRKs and glutamine, an amino acid previously shown to be an itch reliever. Itch responses were evoked by histamine, chloroquine, and dinitrochlorobenzene-induced contact dermatitis (CD). Phosphorylation and protein expression were detected by immunofluorescent staining and Western blotting. GRK2 knockdown using small interfering RNA enhanced itch responses evoked by histamine, chloroquine, and dinitrochlorobenzene-induced CD, whereas GRK2 overexpression using GRK2-expressing adenovirus reduced the itch responses. Glutamine reduced all itch evoked by histamine, chloroquine, and dinitrochlorobenzene-induced CD. Glutamine-mediated inhibition of itch was abolished by GRK2 knockdown. Glutamine application resulted in a rapid and strong expression of GRK2 in not only dinitrochlorobenzene-induced CD (within 10 minutes) but also cultured rat dorsal root ganglion cells, F11 (within 1 minute). ERK inhibitor abrogates glutamine-mediated GRK2 expression and inhibition of itch in dinitrochlorobenzene-induced CD. Our data indicate that GRK2 is a key negative regulator of itch and that glutamine attenuates itch via a rapid induction of GRK2 in an ERK-dependent way.

Radiation safety: a focus on lead aprons and thyroid shields in interventional pain management.

C-arm fluoroscopy is useful equipment in interventional pain management because it helps to guide correct needle targeting for the accurate injection and drug delivery. However, due to increased use of C-arm fluoroscopy in various pain procedures, the risk of radiation exposure is a significant concern for pain physicians. The harmful biological effects of ionizing radiation on the human body are well known. It is therefore necessary to strive to reduce radiation exposure. Lead aprons with thyroid shields are the most fundamental radiation protective devices for interventional procedures, and are very effective. However, the operator's radiation safety cannot be guaranteed because pain physicians seem to lack sufficient interest, knowledge, and awareness about radiation safety. Also, inappropriate care and use of radiation protective devices may result in a higher risk of radiation exposure. The purpose of this article was to review the literature on radiation safety with a focus on lead aprons and thyroid shields and present recommendations related to those devices during C-arm fluoroscopic-guided interventions by pain physicians.

The radiation safety education and the pain physicians' efforts to reduce radiation exposure.

BACKGROUND: C-arm fluoroscopy equipment is important for interventional pain management and can cause radiation injury to physicians and patients. We compared radiation safety education and efforts to reduce the radiation exposure of pain specialists. METHODS: A survey of 49 pain specialists was conducted anonymously in 2016. The questionnaire had 16 questions. That questionnaire was about radiation safety knowledge and efforts to reduce exposure. We investigated the correlation between radiation safety education and efforts of radiation protection. We compared the results from 2016 and a published survey from 2011. RESULTS: According to the 2016 survey, all respondents used C-arm fluoroscopy in pain interventions. Nineteen respondents (39%) had received radiation safety education. Physicians had insufficient knowledge about radiation safety. When the radiation safety education group and the non-education group are compared, there was no significant difference in efforts to reduce radiation exposure and radiation safety knowledge. When the 2011 and 2016 surveys were compared, the use of low dose mode (P = 0.000) and pulsed mode had increased significantly (P = 0.001). The number checking for damage to radiation protective garments (P = 0.000) and use of the dosimeter had also increased significantly (P = 0.009). But there was no significant difference in other efforts to reduce radiation exposure. CONCLUSIONS: Pain physicians seem to lack knowledge of radiation safety and the number of physicians receiving radiation safety education is low. According to this study, education does not lead to practice. Therefore, pain physicians should receive regular radiation safety education and the education should be mandatory.

Effects of intravenous anesthetics on the activity of glutamate transporter EAAT3 expressed in Xenopus oocytes: evidence for protein kinase C involvement.

We investigated the effects of the intravenous anesthetics, thiopental, etomidate and ketamine, on the activity of one type of glutamate transporters, EAAT3 (excitatory amino acid transporter type 3). Rat EAAT3 was expressed in Xenopus oocytes by injection of its mRNA. Using two-electrode voltage clamp, membrane currents were recorded after the application of L-glutamate (30 microM) in the presence or absence of various concentrations of the anesthetics. Thiopental (0.3-30 microM) and ketamine (3-1000 microM) did not affect EAAT3 activity. Etomidate decreased EAAT3 activity in a concentration-dependent manner (0.10-10 microM). Etomidate at 1 microM significantly decreased the Vmax, but not the Km of EAAT3 for glutamate. Chelerythrine, a protein kinase C (PKC) inhibitor, significantly decreased EAAT3 activity, however, there were no statistical differences among the chelerythrine, etomidate or chelerythrine plus etomidate groups. Likewise, the combination of staurosporine, another PKC inhibitor, and etomidate did not decrease the responses further compared with staurosporine or etomidate alone. Phorbol-12-myrisate-13-acetate, a PKC activator, abolished etomidate-induced decrease in EAAT3 activity. Since our results showed that thiopental and ketamine did not affect EAAT3 activity significantly, EAAT3 may not be a target for their anesthetic effects. Our results also suggest that etomidate, possibly via PKC, decreased EAAT3 activity at clinically relevant concentrations.

Glutamine up-regulates MAPK phosphatase-1 induction via activation of Ca2+→ ERK cascade pathway.

The non-essential amino acid L-glutamine (Gln) displays potent anti-inflammatory activity by deactivating p38 mitogen activating protein kinase and cytosolic phospholipase A2 via induction of MAPK phosphatase-1 (MKP-1) in an extracellular signal-regulated kinase (ERK)-dependent way. In this study, the mechanism of Gln-mediated ERK-dependency in MKP-1 induction was investigated. Gln increased ERK phosphorylation and activity, and phosphorylations of Ras, c-Raf, and MEK, located in the upstream pathway of ERK, in response to lipopolysaccharidein vitro and in vivo. Gln-induced dose-dependent transient increases in intracellular calcium ([Ca2+]i) in MHS macrophage cells. Ionomycin increased [Ca2+]i and activation of Ras → ERK pathway, and MKP-1 induction, in the presence, but not in the absence, of LPS. The Gln-induced pathways involving Ca2+→ MKP-1 induction were abrogated by a calcium blocker. Besides Gln, other amino acids including L-phenylalanine and l-cysteine (Cys) also induced Ca2+ response, activation of Ras → ERK, and MKP-1 induction, albeit to a lesser degree. Gln and Cys were comparable in suppression against 2, 4-dinitrofluorobenzene-induced contact dermatitis. Gln-mediated, but not Cys-mediated, suppression was abolished by MKP-1 small interfering RNA. These data indicate that Gln induces MKP-1 by activating Ca2+→ ERK pathway, which plays a key role in suppression of inflammatory reactions.

Spinal Cauda Equina Stimulation for Alternative Location of Spinal Cord Stimulation in Intractable Phantom Limb Pain Syndrome: A Case Report.

Phantom limb pain is a phenomenon in which patients experience pain in a part of the body that no longer exists. In several treatment modalities, spinal cord stimulation (SCS) has been introduced for the management of intractable post-amputation pain. A 46-year-old male patient complained of severe ankle and foot pain, following above-the-knee amputation surgery on the right side amputation surgery three years earlier. Despite undergoing treatment with multiple modalities for pain management involving numerous oral and intravenous medications, nerve blocks, and pulsed radiofrequency (RF) treatment, the effect duration was temporary and the decreases in the patient's pain score were not acceptable. Even the use of SCS did not provide completely satisfactory pain management. However, the trial lead positioning in the cauda equina was able to stimulate the site of the severe pain, and the patient's pain score was dramatically decreased. We report a case of successful pain management with spinal cauda equina stimulation following the failure of SCS in the treatment of intractable phantom limb pain.

Antimicrobial activity of berberine alone and in combination with ampicillin or oxacillin against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) bacteria have been responsible for substantial morbidity and mortality in hospitals because they usually have multidrug resistance. Some natural products are candidates as new antibiotic substances. In the present study, we investigated the antimicrobial activity of berberine, the main antibacterial substance of Coptidis rhizoma (Coptis chinensis Franch) and Phellodendri cortex (Phellodendron amurense Ruprecht), against clinical isolates of MRSA, and the effects of berberine on the adhesion to MRSA and intracellular invasion into human gingival fibroblasts (HGFs). Berberine showed antimicrobial activity against all tested strains of MRSA. Minimum inhibition concentrations (MICs) of berberine against MRSA ranged from 32 to 128 microg/mL. Ninety percent inhibition of MRSA was obtained with 64 microg/mL or less of berberine. In the checkerboard dilution test, berberine markedly lowered the MICs of ampicillin and oxacillin against MRSA. An additive effect was found between berberine and ampicillin, and a synergistic effect was found between berberine and oxacillin against MRSA. In the presence of 1-50 microg/mL berberine, MRSA adhesion and intracellular invasion were notably decreased compared with the vehicle-treated control group. These results suggest that berberine may have antimicrobial activity and the potential to restore the effectiveness of beta-lactam antibiotics against MRSA, and inhibit the MRSA adhesion and intracellular invasion in HGFs.

Simultaneous determination of ginsenoside Rb(1) and Rg(1) in human plasma by liquid chromatography-mass spectrometry.

A liquid chromatographic-mass spectrometric (LC/MS) method for the simultaneous determination of ginsenoside Rb(1) and Rg(1) in human plasma was developed. The method involved the protein precipitation followed by analysis of ginsenoside Rb(1) and Rg(1) in an Atlantis C(18) column with the gradient elution of acetonitrile and ammonium formate (10mM, pH 3.0) at a flow rate of 0.2 ml/min. The analytes were determined using electrospray negative ionization mass spectrometry in the selected ion monitoring mode. The standard curves for ginsenoside Rb(1) and Rg(1) were linear over the concentration range of 10.0-1000 ng/ml. The lower limit of quantification was 10.0 ng/ml using 100 microl plasma sample. The coefficient of variation of intra- and inter-day assays for ginsenoside Rb(1) and Rg(1) at three quality control levels ranged from 1.0 to 6.8% and 5.4 to 9.8%, respectively. Ginsenoside Rb(1) and Rg(1) were stable in blank human plasma at room temperature for 24h and following three freeze-thaw cycles.

Determination of butein in rat serum by high performance liquid chromatography.

A simple high performance liquid chromatography (HPLC) method was developed for the determination of butein in rat serum. The method involved the deproteinization followed by injection into a Luna C8 column. Butein was eluted at 3.8 min at a flow rate of 0.2 ml/min with the mobile phase of acetonitrile-ammonium formate (10mM, pH 3.0) (35:65, v/v). The standard curve was linear (r(2)=0.995) over the concentration range of 0.1-10 microg/ml. The coefficient of variation (CV) of intra- and inter-assay ranged from 2.7 to 7.5% and 6.0 to 7.5%, respectively. The limit of quantification was 0.1 microg/ml using a serum sample of 50 microl. This method was applied to a pharmacokinetic study after intravenous injection of butein (5mg/kg) to rats.

The Radiation Exposure of Radiographer Related to the Location in C-arm Fluoroscopy-guided Pain Interventions.

BACKGROUND: Although a physician may be the nearest to the radiation source during C-arm fluoroscope-guided interventions, the radiographer is also near the fluoroscope. We prospectively investigated the radiation exposure of radiographers relative to their location. METHODS: The effective dose (ED) was measured with a digital dosimeter on the radiographers' left chest and the side of the table. We observed the location of the radiographers in each procedure related to the mobile support structure of the fluoroscope (Groups A, M and P). Data about age, height, weight, sex, exposure time, radiation absorbed dose (RAD), and the ED at the radiographer's chest and the side of the table was collected. RESULTS: There were 51 cases for Group A, 116 cases for Group M and 144 cases for Group P. No significant differences were noted in the demographic data such as age, height, weight, and male to female ratio, and exposure time, RAD and ED at the side of the table. Group P had the lowest ED (0.5 ± 0.8 µSv) of all the groups (Group A, 1.6 ± 2.3 µSv; Group M, 1.3 ± 1.9 µSv; P < 0.001). The ED ratio (ED on the radiographer's chest/ED at the side of the table) of Group A was the highest, and the ED radio of Group P was the lowest of all the groups (Group A, 12.2 ± 21.5%; Group M, 5.7 ± 6.5%; Group P, 2.5 ± 6.7%; P < 0.001). CONCLUSIONS: Radiographers can easily reduce their radiation exposure by changing their position. Two steps behind the mobile support structure can effectively decrease the exposure of radiographers by about 80%.

Glutamine suppresses DNFB-induced contact dermatitis by deactivating p38 mitogen-activated protein kinase via induction of MAPK phosphatase-1.

L-glutamine (Gln) is a nonessential amino acid that is the most abundant amino acid in plasma. Gln has been reported to have an anti-inflammatory activity that involves deactivation of mitogen-activated protein kinases (MAPKs) in a MAPK phosphatase (MKP)-1-dependent manner. This study investigated the role of Gln in the inhibition of DNFB-induced allergic contact dermatitis (CD) in the ears of mice, and specifically the involvement of Gln in p38 MAPK inhibition. Topical application of Gln or the p38 inhibitor, SB202190, suppressed DNFB-induced CD. Gln application inhibited DNFB-induced p38 phosphorylation. Western blot analysis revealed that Gln application resulted in early phosphorylation and protein induction of MKP-1. MKP-1 small interfering RNA (siRNA), but not control siRNA, abrogated Gln-mediated early phosphorylation, protein induction of MKP-1, deactivation of p38, and Gln-mediated suppression of CD. The extracellular signal-regulated kinase (ERK) inhibitor, U0126, blocked Gln-induced MKP-1 phosphorylation and protein induction, as well as Gln suppression of CD. These results suggest that Gln suppresses DNFB-induced CD via deactivation of p38 MAPK through the early induction of MKP-1, the negative regulator of p38, in an ERK-dependent manner.