Yasuhiro Koide

Spectral analyses of electroencephalography and heart rate variability during sleep in normal subjects.

We investigated the relationship between electroencephalogram (EEG) activity and autonomic nervous system function using spectral analyses of EEG and heart rate variability (HRV) in healthy subjects during sleep. Eleven subjects were enrolled in this study. From EEG, the spectral edge frequencies (SEFs including SEF50, SEF90 and SEF95) were calculated. From electrocardiogram (ECG), the spectral powers of low-frequency band (LF: 0.04-0.15 Hz), high-frequency band (HF: 0.15-0.4 Hz) and the ratio of LF to HF (LF/HF) were calculated. During sleep, each set of data was obtained as the average of a 5-min measurement. We found that SEFs and LF/HF or LF decreased simultaneously and periodically, suggesting simultaneous depression of EEG activity and relative sympathetic activity, and SEFs significantly correlated with LF/HF and LF in all subjects during sleep, but not with HF. The existence of a clear correlation of SEFs with LF or LF/HF may offer a simple approach to estimate the relationship between EEG activity and autonomic nervous system function during sleep.

A lectin from the mussel Mytilus galloprovincialis has a highly novel primary structure and induces glycan-mediated cytotoxicity of globotriaosylceramide-expressing lymphoma cells.

Background: Studies on the diversity of carbohydrate-binding proteins (lectins) are important in glycobiology. Results: A lectin having a novel primary structure was isolated from a mussel and found to have a globotriose-dependent cytotoxicity on Burkitt lymphoma cells. Conclusion: A new primary structure quite distinct from known lectin is described. Significance: Discovery of similar lectin structures from vertebrates will lead to progress in medical sciences. A novel lectin structure was found for a 17-kDa α-d-galactose-binding lectin (termed “MytiLec”) isolated from the Mediterranean mussel, Mytilus galloprovincialis. The complete primary structure of the lectin was determined by Edman degradation and mass spectrometric analysis. MytiLec was found to consist of 149 amino acids with a total molecular mass of 16,812.59 Da by Fourier transform-ion cyclotron resonance mass spectrometry, in good agreement with the calculated value of 16,823.22 Da. MytiLec had an N terminus of acetylthreonine and a primary structure that was highly novel in comparison with those of all known lectins in the structure database. The polypeptide structure consisted of three tandem-repeat domains of ∼50 amino acids each having 45–52% homology with each other. Frontal affinity chromatography technology indicated that MytiLec bound specifically to globotriose (Gb3; Galα1–4Galβ1–4Glc), the epitope of globotriaosylceramide. MytiLec showed a dose-dependent cytotoxic effect on human Burkitt lymphoma Raji cells (which have high surface expression of Gb3) but had no such effect on erythroleukemia K562 cells (which do not express Gb3). The cytotoxic effect of MytiLec was specifically blocked by the co-presence of an α-galactoside. MytiLec treatment of Raji cells caused increased binding of anti-annexin V antibody and incorporation of propidium iodide, which are indicators of cell membrane inversion and perforation. MytiLec is the first reported lectin having a primary structure with the highly novel triple tandem-repeat domain and showing transduction of apoptotic signaling against Burkitt lymphoma cells by interaction with a glycosphingolipid-enriched microdomain containing Gb3.

MytiLec, a Mussel R-Type Lectin, Interacts with Surface Glycan Gb3 on Burkitt's Lymphoma Cells to Trigger Apoptosis through Multiple Pathways

MytiLec; a novel lectin isolated from the Mediterranean mussel (Mytilus galloprovincialis); shows strong binding affinity to globotriose (Gb3: Galα1-4Galβ1-4Glc). MytiLec revealed β-trefoil folding as also found in the ricin B-subunit type (R-type) lectin family, although the amino acid sequences were quite different. Classification of R-type lectin family members therefore needs to be based on conformation as well as on primary structure. MytiLec specifically killed Burkitts lymphoma Ramos cells, which express Gb3. Fluorescein-labeling assay revealed that MytiLec was incorporated inside the cells. MytiLec treatment of Ramos cells resulted in activation of both classical MAPK/ extracellular signal-regulated kinase and extracellular signal-regulated kinase (MEK-ERK) and stress-activated (p38 kinase and JNK) Mitogen-activated protein kinases (MAPK) pathways. In the cells, MytiLec treatment triggered expression of tumor necrosis factor (TNF)-α (a ligand of death receptor-dependent apoptosis) and activation of mitochondria-controlling caspase-9 (initiator caspase) and caspase-3 (activator caspase). Experiments using the specific MEK inhibitor U0126 showed that MytiLec-induced phosphorylation of the MEK-ERK pathway up-regulated expression of the cyclin-dependent kinase inhibitor p21, leading to cell cycle arrest and TNF-α production. Activation of caspase-3 by MytiLec appeared to be regulated by multiple different pathways. Our findings, taken together, indicate that the novel R-type lectin MytiLec initiates programmed cell death of Burkitt’s lymphoma cells through multiple pathways (MAPK cascade, death receptor signaling; caspase activation) based on interaction of the lectin with Gb3-containing glycosphingolipid-enriched microdomains on the cell surface.

Cytotoxicity and Glycan-Binding Properties of an 18 kDa Lectin Isolated from the Marine Sponge Halichondria okadai

A divalent cation-independent lectin-HOL-18, with cytotoxic activity against leukemia cells, was purified from a demosponge, Halichondria okadai. HOL-18 is a 72 kDa tetrameric lectin that consists of four non-covalently bonded 18 kDa subunits. Hemagglutination activity of the lectin was strongly inhibited by chitotriose (GlcNAcβ1-4GlcNAcβ1-4GlcNAc), fetuin and mucins from porcine stomach and bovine submaxillary gland. Lectin activity was stable at pH 4-12 and temperatures lower than 60 °C. Frontal affinity chromatography with 16 types of pyridylaminated oligosaccharides indicated that the lectin had an affinity for N-linked complex-type and sphingolipid-type oligosaccharides with N-acetylated hexosamines and neuramic acid at the non-reducing termini. The lectin killed Jurkat leukemia T cells and K562 erythroleukemia cells in a dose- and carbohydrate-dependent manner.

Multiplane transesophageal echocardiographic guidance during resection of renal cell carcinoma extending into the inferior vena cava

I t has been reported previously that biplane transesophageal echocardiography (TEE) is useful to ascertain the extent of invasion of renal cell carcinoma in the inferior vena cava (IVC) and the right atrium (l-3). In this report, we describe anesthetic management using TEE with multiplane imaging to guide manipulation of a vena caval balloon for occlusion of the IVC just above the tumor, while permitting maintenance of flow from the hepatic vein into the atrium and facilitating removal of renal cell carcinoma extending into the IVC.

ATP-induced ventricular asystole and hypotension during endovascular stenting surgery.

PurposeTo describe four cases of endoluminal stenting surgery in which adenosine 5′-triphosphate (ATP) was used to arrest the heart for accurate placement of the stent-graft.Clinical featuresFour patients with descending thoracic aortic aneurysm were anaesthetized for deployment of a self-expanding stent-graft. Maintenance of general anaesthesia was performed with isoflurane and nitrous oxide in three patients, and with fentanyl and propofol in another. An initial trial of 20 mg ATP was administered via a central venous catheter as rapidly as possible, and produced third degree AV block of 8 ± 1.7 sec and 59.7 ± 17.5 sec: hypotension, mean blood pressure < 60 mmHg, in three patients. The time to onset of AV block was 15.7 ± 6.7 sec. In these patients, deployment of the stent-graft was performed during ventricular asystole produced by 30 mg ATP, which produced 16.3 ± 2.1 sec third and second degree AV block. In one patient anaesthetized with fentanyl and propofol, 20 mg ATP did not change AV conduction. However, after 10 mg edrophonium, 20 mg ATP produced 9 sec third degree AV block. In all cases, heart rate and PQ interval were restored to the pre-drug control level within 50 sec after the commencement of AV block. There were no clinical complications related to this procedure in any patient.ConclusionATP is a convenient and suitable agent to produce transient ventricular asystole for the precise deployment of a self-expanding stent-graft. Co-administration of a parasympathomimetic agent might potentiate the inhibitory effect of ATP on AV conduction.RésuméObjectifDécrire quatre cas de chirurgie par prothèse endoluminale pendant lesquelles l’adénosine 5′-triphosphate (ATP) a été utilisée pour arrêter le cœur et permettre un positionnement précis du système greffe-tuteur.Aspects cliniquesQuatre patients porteurs d’anévrysme de l’aorte thoracique descendante ont été anesthésiés pour mise en place d’un système greffe-tuteur autodéployant. Le maintien de l’anesthésie générale a été obtenu grâce à l’isoflurane et au protoxyde d’azote chez trois patients, et grâce au fentanyl et propofol chez le quatrième. Un essai initial d’une dose de 20 mg d’ATP, administrée aussi rapidement que possible par cathéter central, a entraîné un bloc AV du 3e degré d’une durée de 8 ± 1.7 sec et une hypotension à ≤ 60 mmHg de pression moyenne d’une durée de 59,7 ± 17.5 sec, chez trois patients. Le délai avant le début du bloc AV était de 15.7 ± 6.7 sec. Chez ces patients, on a déployé le système greffe-tuteur durant une asystolie ventriculaire provoquée par une dose de 30 mg d’ATP qui a entraîné un bloc AV du 3e et du 2e degré d’une durée totale de 16.3 ± 2.1 sec. Chez le patient anesthésié avec propofol et fentanyl, l’injection de 20 mg d’ATP n’a pas modifié la conduction AV Cependant, après 10 mg d’édrophonium, la même dose d’ATP a entraîné un bloc AV du 3e degré d’une durée de 9 sec. Chez tous les patients, le rythme cardiaque et l’intervalle PQ étaient revenus aux valeurs contrôle moins de 50 secondes après le début du bloc AV On n’a pas rencontré de complications cliniques reliées à cette procédure chez aucun des patients.ConclusionLATP est un médicament adéquat et pratique pour provoquer une asystolie transitoire permettant le déploiement précis d’un système de greffe-tuteur autodéployant. Ladministration concomitante d’un agent parasympathomimétique peut potentialiser l’effet inhibiteur de l’ATP sur la conduction AV

An intraoperative diagnosis of dynamic left ventricular outflow tract obstruction using transesophageal echocardiography leads to the treatment with intravenous disopyramide.

UNLABELLED Hypertrophic obstructive cardiomyopathy (HOCM) is an uncommon familial disorder, traditionally characterized by asymmetric septal hypertrophy and left ventricular outflow tract (LVOT) obstruction (1). It is now recognized that HOCM may also include those patients with secondary left ventricular hypertrophy (LVH) and dynamic LVOT obstruction. In particular, a syndrome with similar clinical and echocardiographic findings has been identified in elderly patients exhibiting concentric LVH with chronic hypertension, aortic stenosis, or sigmoid-shaped septum (2). IMPLICATIONS During surgery, dynamic left ventricular outflow obstruction (LVOT) can potentially occur frequently, but diagnosis may be less frequent. When circulatory disturbance occurs with suspicion of LVOT obstruction, transesophageal echocardiography can provide exact proof of diagnosis and basis for immediate treatment.

cDNA and Gene Structure of MytiLec-1, A Bacteriostatic R-Type Lectin from the Mediterranean Mussel (Mytilus galloprovincialis).

MytiLec is an α-d-galactose-binding lectin with a unique primary structure isolated from the Mediterranean mussel (Mytilus galloprovincialis). The lectin adopts a β-trefoil fold that is also found in the B-sub-unit of ricin and other ricin-type (R-type) lectins. We are introducing MytiLec(-1) and its two variants (MytiLec-2 and -3), which both possess an additional pore-forming aerolysin-like domain, as members of a novel multi-genic “mytilectin family” in bivalve mollusks. Based on the full length mRNA sequence (911 bps), it was possible to elucidate the coding sequence of MytiLec-1, which displays an extended open reading frame (ORF) at the 5′ end of the sequence, confirmed both at the mRNA and at the genomic DNA sequence level. While this extension could potentially produce a polypeptide significantly longer than previously reported, this has not been confirmed yet at the protein level. MytiLec-1 was revealed to be encoded by a gene consisting of two exons and a single intron. The first exon comprised the 5′UTR and the initial ATG codon and it was possible to detect a putative promoter region immediately ahead of the transcription start site in the MytiLec-1 genomic locus. The remaining part of the MytiLec-1 coding sequence (including the three sub-domains, the 3′UTR and the poly-A signal) was included in the second exon. The bacteriostatic activity of MytiLec-1 was determined by the agglutination of both Gram-positive and Gram-negative bacteria, which was reversed by the co-presence of α-galactoside. Altogether, these data support the classification of MytiLec-1 as a member of the novel mytilectin family and suggest that this lectin may play an important role as a pattern recognition receptor in the innate immunity of mussels.

A Galactose-Binding Lectin Isolated from Aplysia kurodai (Sea Hare) Eggs Inhibits Streptolysin-Induced Hemolysis

A specific galactose-binding lectin was shown to inhibit the hemolytic effect of streptolysin O (SLO), an exotoxin produced by Streptococcus pyogenes. Commercially available lectins that recognize N-acetyllactosamine (ECA), T-antigen (PNA), and Tn-antigen (ABA) agglutinated rabbit erythrocytes, but had no effect on SLO-induced hemolysis. In contrast, SLO-induced hemolysis was inhibited by AKL, a lectin purified from sea hare (Aplysia kurodai) eggs that recognizes α-galactoside oligosaccharides. This inhibitory effect was blocked by the co-presence of d-galactose, which binds to AKL. A possible explanation for these findings is that cholesterol-enriched microdomains containing glycosphingolipids in the erythrocyte membrane become occupied by tightly stacked lectin molecules, blocking the interaction between cholesterol and SLO that would otherwise result in penetration of the membrane. Growth of S. pyogenes was inhibited by lectins from a marine invertebrate (AKL) and a mushroom (ABA), but was promoted by a plant lectin (ECA). Both these inhibitory and promoting effects were blocked by co-presence of galactose in the culture medium. Our findings demonstrate the importance of glycans and lectins in regulating mechanisms of toxicity, creation of pores in the target cell membrane, and bacterial growth.

Binding profiles and cytokine-inducing effects of fish rhamnose-binding lectins on Burkitt’s lymphoma Raji cells

Rhamnose-binding lectin (RBL) is one of the animal lectin categories which take part in the innate immune responses of fish. Osmerus lanceolatus lectin (OLL) from shishamo smelt eggs is an RBL composed of two tandem-repeated domains, both of which are considered to be a carbohydrate-recognition domain. SAL, catfish (Silurus asotus) egg RBL composed of three domains, binds to Burkitt’s lymphoma Raji cells through globotriaosylceramide (Gb3) carbohydrate chain and to reduce cell size and growth by altering membrane composition without causing cell death. In this experiment, we tried to compare the binding effects of these two RBLs on Raji cells. Flow cytometric and fluorescence microscopic analyses revealed that OLL also directly bound to and shrunk Raji cells with ten times less reactivity than SAL but reduced cell growth with decreasing cell viability. Anti-Gb3 antibody completely blocked the binding of SAL to Raji cells but not that of OLL. In addition, the direct bindings of OLL and SAL to Raji cells were comparably inhibited by melibiose, but lactose was more effective inhibitor for the binding of OLL than that of SAL. These results suggest that OLL has slightly different cell-binding property compared with SAL and binds not only to Gb3 but also to the other carbohydrate receptor-bearing β-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-α but not of IFN-γ, IL-1β, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-α-mediated signaling pathway.Rhamnose-binding lectin (RBL) is one of the animal lectin categories which take part in the innate immune responses of fish. Osmerus lanceolatus lectin (OLL) from shishamo smelt eggs is an RBL composed of two tandem-repeated domains, both of which are considered to be a carbohydrate-recognition domain. SAL, catfish (Silurus asotus) egg RBL composed of three domains, binds to Burkitt’s lymphoma Raji cells through globotriaosylceramide (Gb3) carbohydrate chain and to reduce cell size and growth by altering membrane composition without causing cell death. In this experiment, we tried to compare the binding effects of these two RBLs on Raji cells. Flow cytometric and fluorescence microscopic analyses revealed that OLL also directly bound to and shrunk Raji cells with ten times less reactivity than SAL but reduced cell growth with decreasing cell viability. Anti-Gb3 antibody completely blocked the binding of SAL to Raji cells but not that of OLL. In addition, the direct bindings of OLL and SAL to Raji cells were comparably inhibited by melibiose, but lactose was more effective inhibitor for the binding of OLL than that of SAL. These results suggest that OLL has slightly different cell-binding property compared with SAL and binds not only to Gb3 but also to the other carbohydrate receptor-bearing β-galactoside chains. The quantitative RT-PCR analysis revealed that SAL induced the expression of TNF-α but not of IFN-γ, IL-1β, and IL-10. Thus, SAL-induced cytostatic effect on Raji cells might be partially caused by TNF-α-mediated signaling pathway.