Shuichi Nosaka

Capillary endothelial thrombomodulin expression and fibrin deposition in rats with continuous and bolus lipopolysaccharide administration.

We studied capillary endothelial injury, as demonstrated by fibrin deposition and changes in thrombomodulin (Tm) expression, in rats receiving continuous or bolus iv lipopolysaccharide (LPS). Rats were continuously infused with iv LPS (0.1, 0.2, 0.5, or 1.0 mg/kg/hr) for up to 6 hours. Others were given a bolus iv dose of LPS (20 mg/kg), and then the same dose of saline as a continuous infusion was administered for up to 3 hours. Harvested lungs, livers, and kidneys were examined immunohistochemically for thrombomodulin expression and fibrin deposition. Tm expression began to diminish dose- and time-dependently in lung, liver, and renal peritubular capillaries within 2 to 4 hours of the start of continuous LPS administration (1.0 mg/kg/hr) and had completely disappeared by 3 hours, although Tm remained in the glomerulus. The amount of fibrin deposition observed varied with the organ, dose, and duration of treatment in rats that received continuous LPS administration, but little was deposited in the lung. After bolus LPS administration, Tm in the endothelia of lung, liver, and peritubular capillaries diminished 20 to 40 minutes after treatment and then recovered 120 to 180 minutes after treatment, but the Tm activity of the glomerulus did not change. Fibrin deposition in the capillaries was observed in the liver, glomerulus, and peritubular capillaries, but not in the lung. Endothelial injury by LPS administration is dependent on the dose of LPS and the duration of treatment. The amount of fibrin deposition differs among organs and with the duration of contact between the endothelium and the endotoxin.

Ca2+ paradox injury mediated through TRPC channels in mouse ventricular myocytes.

BACKGROUND AND PURPOSE The Ca2+ paradox is an important phenomenon associated with Ca2+ overload‐mediated cellular injury in myocardium. The present study was undertaken to elucidate molecular and cellular mechanisms for the development of the Ca2+ paradox.

Changes in regional cerebral blood flow in the thalamus after electroconvulsive therapy for patients with complex regional pain syndrome type 1 (preliminary case series)

Background and Objectives The aim of the present case series was to examine whether changes in regional cerebral blood flow (rCBF) induced by electroconvulsive therapy (ECT) in the thalamus are related to the efficacy of ECT. Four chronic pain patients with complex regional pain syndrome (CRPS) type-1 (age, 33 to 58 years) who had failed to respond to standard pain treatments received a course of ECT. To investigate the possible mechanisms of the analgesic effect of ECT on chronic CRPS type-1, we measured significant changes in the rCBF of the thalamus using technetium-99m ethyl cysteinate dimer single photon emission computed tomography (99mTc ECD SPECT), before and after ECT and compared these values between responders and nonresponders. Results Two of 4 (50.0%) patients responded to ECT treatment (response defined as a reduction of at least 60% on the visual analog scale [VAS]). 99mTc ECD SPECT showed that the mean contralateral thalamus-to-cerebellum ratio increased 11.5% after ECT compared with the ratio before ECT in the 2 responders, but remained unchanged in nonresponders. Conclusions The results from the SPECT suggest that normalization of the balance of rCBF in the thalamus may be related to the analgesic efficacy of the ECT on CRPS Type-1.

Pain patterns originating from the sacroiliac joints

region, the posterior thigh region, and the groin region (Fig. 1). Each patient was asked which region or regions their pain occurred in before they received a SI joint injection. A diagnosis of SI joint pain was made if all of the following clinical features were present: (1) pain perceived in the region of the SI joint with or without referred pain; (2) the injection of a local anesthetic into the capsule of a SI joint relieved the pain by more than 80% compared with the level of pain before the injection; (3) the pain could be reproduced by physical examination techniques which stress the joint (Gaenslen’s test or Patrick’s test) [1,2]. Patients with these criteria were selected for this study. The SI joint injection was performed with the patient lying on a fluoroscopy table in a prone position. A posterior approach allowed visualization of the joints using the technique described by Fortin et al. [4]. Under intermittent fluoroscopic control, and after identifying the inferior extent of the joint, a 22-gauge needle was inserted through the skin from 1–3cm below the inferior margin of the SI joint, and directed cephalad to strike the ilium 1cm above the inferior margin of the joint. The accuracy of the placement was confirmed by arthrography. Once the needle had penetrated the joint capsule, a small amount of contrast medium (Iohexol: omnipaque) was injected until the initial instillation of the contrast medium outlined the joint. The volume of contrast injected averaged 2.4ml per subject (range 2.46 0.66ml). After the injection of contrast medium, a mixture of 2 ml local anesthetic (1% mepivacaine) and 2mg dexamethazone was injected into the joint space as a therapeutic procedure. Patients whose pain was reproduced by intraarticular injection were selected for this study, while those whose pain pattern did not coincide with their original pain were excluded. For the 28 patients enrolled in this study, SI joint injection was performed into a total of 32 joints. Four

Comparative study of the mammalian liver innervation: an immunohistochemical study of protein gene product 9.5, dopamine β-hydroxylase and tyrosine hydroxylase

The liver innervation of eight different mammalian species was examined by immunohistochemical localization of protein gene product (PGP) 9.5 to visualize the general innervation for autonomic nerve fibres. In addition, dopamine beta-hydroxylase (DBH) and tyrosine hydroxylase (TH), two enzymes involved in catecholamine synthesis, were localized immunohistochemically to delineate hepatic sympathetic nerve fibres. We found that: (1) Within the interlobular region of each species, PGP 9.5, DBH and TH-positive nerve fibres were all seen in close association with branches of hepatic arteries, portal veins and bile ducts. (2) Within the parenchyma of the guinea-pig, cat, dog, pig, monkey and human liver, the presence of the three immuno-positive nerve fibres could be unequivocally identified, although the density of these intralobular fibres showed marked species variation. Moreover, immunoelectron microscopic study confirmed that PGP 9.5-positive nerve terminals of the human liver are in close apposition to hepatocytes. (3) In mouse and rat, no parenchymal nerve fibres immunoreactive for PGP 9.5, TH or DBH could be demonstrated.

Noble Gas Binding to Human Serum Albumin Using Docking Simulation : Nonimmobilizers and Anesthetics Bind to Different Sites

BACKGROUND: Nonimmobilizers are structurally similar to anesthetics, but do not produce anesthesia at clinically relevant concentrations. Xenon, krypton, and argon are anesthetics, whereas neon and helium are nonimmobilizers. The structures of noble gases with anesthetics or nonimmobilizers are similar and their interactions are simple. Whether the binding site of anesthetics differs from that of nonimmobilizers has long been a question in molecular anesthesiology. METHODS: We investigated the binding sites and energies of anesthetic and nonimmobilizer noble gases in human serum albumin (HSA) because the 3D structure of HSA is well known and it has an anesthetic binding site. The computational docking simulation we used searches for binding sites and calculates the binding energy for small molecules and a template molecule. RESULTS: Xenon, krypton, and argon were found to bind to the enflurane binding site of HSA, whereas neon and helium were found to bind to sites different from the xenon binding site. Rare gas anesthetic binding was dominated by van der Waals energy, while nonimmobilizer binding was dominated by solvent-effect energy. Binding site preference was determined by the ratios of local binding energy (van der Waals energy) and nonspecific binding energy (solvent-effect energy) to the total binding energy. van der Waals energy dominance is necessary for anesthetic binding. CONCLUSIONS: This analysis of binding energy components provides a rationale for the binding site difference of anesthetics and nonimmobilizers, reveals the differences between the binding interactions of anesthetics and nonimmobilizers, may explain pharmacological differences between anesthetics and nonimmobilizers, and provide an understanding of anesthetic action at the atomic level.

Successful relief of hip joint pain by percutaneous radiofrequency nerve thermocoagulation in a patient with contraindications for hip arthroplasty.

and groin for years. She experienced gradually worsening pain in the inguinal, thigh, and hip area to the level that she could not walk, sit, take care of herself at home, and sleep well. She was only able to ambulate with a wheelchair. The pain was constant, severe, sharp, and deep in her thigh, groin, and hip. It radiated to the left anterior knee at times. Past conservative drug therapy had failed. Hip arthroplasty was contraindicated because of the presence of severe lymphedema and the high risk of infection. The hip x-ray indicated severe bilateral hip joint destruction. MRI of pelvis also indicated severe bilateral hip joint degeneration and destruction.

Sevoflurane protects ventricular myocytes against oxidative stress-induced cellular Ca2+ overload and hypercontracture.

Background:Oxidative stress is implicated in pathogenesis of cardiac reperfusion injury, characterized by cellular Ca2+ overload and hypercontracture. Volatile anesthetics protect the heart against reperfusion injury primarily by attenuating Ca2+ overload. This study investigated electrophysiological mechanisms underlying cardioprotective effects of sevoflurane against oxidative stress-induced cellular injury. Methods:The cytosolic Ca2+ levels and cell morphology were assessed in mouse ventricular myocytes, using confocal fluo-3 fluorescence imaging, whereas membrane potentials and L-type Ca2+ current (ICa,L) were recorded using whole-cell patch-clamp techniques. Phosphorylation of Ca2+/calmodulin-dependent protein kinase II was examined by Western blotting. Results:Exposure to H2O2 (100 &mgr;M) for 15 min evoked cytosolic Ca2+ elevation and hypercontracture in 56.8% of ventricular myocytes in 11 experiments, which was partly but significantly reduced by nifedipine, tetracaine, or SEA0400. Sevoflurane prevented H2O2-induced cellular Ca2+ overload in a concentration-dependent way (IC50 = 1.35%). Isoflurane (2%) and desflurane (10%) also protected ventricular myocytes by a degree similar to sevoflurane (3%). Sevoflurane suppressed H2O2-induced electrophysiological disturbances, including early afterdepolarizations, voltage fluctuations in resting potential, and abnormal automaticities. H2O2 significantly enhanced ICa,L by activating Ca2+/calmodulin-dependent protein kinase II, and subsequent addition of sevoflurane, isoflurane, or desflurane similarly reduced ICa,L to below baseline levels. Phosphorylated Ca2+/calmodulin-dependent protein kinase II increased after 10-min incubation with H2O2, which was significantly prevented by concomitant administration of sevoflurane. Conclusions:Sevoflurane protected ventricular myocytes against H2O2-induced Ca2+ overload and hypercontracture, presumably by affecting multiple Ca2+ transport pathways, including ICa,L, Na+/Ca2+ exchanger and ryanodine receptor. These actions appear to mediate cardioprotection against reperfusion injury associated with oxidative stress.

Presence of store-operated Ca2+ entry in C57BL/6J mouse ventricular myocytes and its suppression by sevoflurane

BACKGROUND Store-operated Ca(2+) entry (SOCE) has been implicated in various pathological conditions of the heart including ischaemia/reperfusion and ventricular hypertrophy. This study investigated the effects of sevoflurane on SOCE. METHODS Fluorescence imaging was performed on fluo-3- and mag-fluo-4-loaded mouse ventricular myocytes to measure the cytosolic and intraluminal sarcoplasmic reticulum (SR) Ca(2+) levels, respectively, using a confocal laser scanning microscope. Whole-cell membrane currents were recorded using the patch-clamp technique. Ventricular myocytes were exposed to thapsigargin and angiotensin II to deplete SR Ca(2+) stores and thereby activate SOCE. RESULTS The combined application of thapsigargin and angiotensin II to the Ca(2+)-free medium evoked a significant decrease in the SR Ca(2+) levels, which was followed by the elevation of cytosolic Ca(2+) and the development of cellular hypercontracture upon subsequent addition of extracellular Ca(2+). This cytosolic Ca(2+) elevation was inhibited by 2-aminoethoxydiphenyl borate but not by verapamil and KB-R7943, which indicates that SOCE was present in mouse ventricular myocytes. Sevoflurane concentration-dependently inhibited the SOCE-mediated Ca(2+) overload (IC(50) of 137 μM, which corresponds to 0.96%) with a significant reduction occurring at concentrations of ≥2%. Patch-clamp experiments revealed that the SOCE current was also concentration-dependently blocked by sevoflurane (IC(50) of 144 μM, which corresponds to 1.0%). CONCLUSIONS Sevoflurane at concentrations of ≥2% significantly inhibits the SOCE activity and prevents the resultant cellular Ca(2+) overload that leads to hypercontracture in ventricular myocytes. This inhibitory action may be involved in the cardioprotective effect of sevoflurane against Ca(2+) overload-mediated injury.

Chronic pain with beneficial response to electroconvulsive therapy and regional cerebral blood flow changes assessed by single photon emission computed tomography

Background Recent neuroimaging studies suggested that chronic neuropathic pain may be largely sustained by a complex neuronal network involving the thalamus. Although recent studies have demonstrated the efficacy of electroconvulsive therapy (ECT) in the treatment of a variety of types of chronic neuropathic pain, the effects of ECT on regional cerebral blood flow (rCBF) have not been studied. Objectives and Methods We present a 50-year-old female postsurgical chronic pain patient whose pain had failed to respond to standard pain treatment, but was resolved by ECT. To investigate the potential role of rCBF in ECT’s analgesic effect, we measured significant changes in the rCBF in the thalamus before and after a course of bilateral ECT using technetium-99m ethyl cysteinate dimer (99mTc-ECD) single photon emission computed tomography (SPECT). Results 99mTc-ECD SPECT showed a significant bilateral decrease in the thalamus on the side of the pain, and this decreased rCBF in the thalamus increased after ECT. Conclusions The results from the SPECT suggest that ECT increases abnormally decreased thalamus activity in chronic neuropathic pain.