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1.
J Dent Res ; 95(10): 1138-46, 2016 Sep.
Article de Anglais | MEDLINE | ID: mdl-27302878

RÉSUMÉ

Burning mouth syndrome (BMS) is an idiopathic orofacial pain condition. Although the pathophysiology of BMS is not clearly understood, central and peripheral neuropathic mechanisms are thought to be involved. The authors compared brain response to noxious heat stimuli in 16 right-handed women with primary BMS and 15 sex- and age-matched right-handed healthy female controls. A thermal stimulus sequence of 32 °C to 40 °C to 32 °C to 49 °C was repeated 4 times in a cycle. Warm and noxious heat stimuli were delivered with a Peltier thermode placed on the right palm or right lower lip for 32 s each in a session. Functional magnetic resonance imaging data were obtained by recording echoplanar images with a block design. Statistical Parametric Mapping 8 software was used to analyze the data. Patients and controls both reported feeling more pain during palm stimulation than during lip stimulation. Repetition of noxious heat stimulus on the lower lip but not on the palm induced habituation in brain activity in the cingulate cortex without reduction in pain perception. Multiple regression analysis revealed a correlation between perceived pain intensity and suppression of brain activity in the anterior cingulate cortex when the repeated thermal sequence was applied at the lower lip. Furthermore, the response of the parahippocampal area differed in BMS patients and controls when the same repeated thermal sequence was applied at the palm. The authors' findings indicate that BMS patients show specific brain responses due to impaired function of the central and peripheral nervous systems (clinical trial registration: UMIN000015002).


Sujet(s)
Cartographie cérébrale/méthodes , Stomatodynie/physiopathologie , Adulte , Études cas-témoins , Femelle , Gyrus du cingulum/physiopathologie , Main , Hippocampe/physiopathologie , Température élevée , Humains , Interprétation d'images assistée par ordinateur , Lèvre , Imagerie par résonance magnétique , Adulte d'âge moyen , Mesure de la douleur , Perception de la douleur/physiologie
2.
Blood Cancer J ; 4: e174, 2014 Jan 10.
Article de Anglais | MEDLINE | ID: mdl-24413068

RÉSUMÉ

A single somatic mutation, V617F, in Janus kinase 2 (JAK2) is one of the causes of myeloproliferative neoplasms (MPNs), including primary myelofibrosis, and the JAK2V617F mutant kinase is a therapeutic target in MPN. However, inhibition of wild-type (WT) JAK2 can decrease the erythrocyte or platelet (PLT) count. Our selective JAK2 inhibitor, NS-018, suppressed the growth of Ba/F3 cells harboring JAK2V617F more strongly than that of cells harboring WT JAK2. The 4.3-fold JAK2V617F selectivity of NS-018 is higher than the 1.0- to 2.9-fold selectivity of seven existing JAK2 inhibitors. NS-018 also inhibited erythroid colony formation in JAK2V617F transgenic mice at significantly lower concentrations than in WT mice. In keeping with the above results, in a JAK2V617F bone marrow transplantation mouse model with a myelofibrosis-like disease, NS-018 reduced leukocytosis and splenomegaly, improved bone marrow fibrosis and prolonged survival without decreasing the erythrocyte or PLT count in the peripheral blood. By exploring the X-ray co-crystal structure of NS-018 bound to JAK2, we identified unique hydrogen-bonding interactions between NS-018 and Gly993 as a plausible explanation for its JAK2V617F selectivity. These results suggest that NS-018 will have therapeutic benefit for MPN patients through both its efficacy and its reduced hematologic adverse effects.

3.
J Dent Res ; 92(5): 456-60, 2013 May.
Article de Anglais | MEDLINE | ID: mdl-23520364

RÉSUMÉ

The exact mechanism underlying chronic masseter muscle pain, a conspicuous symptom in temporomandibular disorder, remains unclear. We investigated whether expression of P2X3 receptor (P2X3R) is involved in mechanical hyperalgesia after contraction of masseter muscle (CMM). As compared with sham rats, the head-withdrawal threshold (HWT) to mechanical pressure stimulation of masseter muscle (MM) (but not after similar stimulation of facial skin) was significantly lower, and IL-1ß level was significantly higher, in CMM rats on day 7 after CMM. The mean percentage of FG-labeled P2X3R-positive neurons was significantly increased in TG following successive IL-1ß injections into the MM for 7 days. Successive administration of an IL-1ß receptor-antagonist into the MM attenuated the increase of P2X3-IR cells in the TG. ATP release from MM after 300-g pressure stimulation of MM was also significantly enhanced after CMM. Administration into MM of the selective P2X3,2/3 receptor antagonist A-317491 attenuated the decrement of HWT in CMM rats. A significant increase in HWT was also observed at 30 min after A-317491 (60 µg) injection in IL-1ß-injected rats. These findings suggest that P2X3R expression associated with enhanced IL-1ß expression and ATP release in MM has a possible important role in MM mechanical hyperalgesia after excessive muscular contraction.


Sujet(s)
Névralgie faciale/métabolisme , Interleukine-1 bêta/métabolisme , Muscle masséter/métabolisme , Contraction musculaire/physiologie , Récepteurs purinergiques P2X3/métabolisme , Adénosine triphosphate/métabolisme , Animaux , Stimulation électrique , Névralgie faciale/complications , Névralgie faciale/physiopathologie , Hyperalgésie/complications , Hyperalgésie/métabolisme , Hyperalgésie/physiopathologie , Mâle , Muscle masséter/physiopathologie , Antagonistes des récepteurs purinergiques P2X/pharmacocinétique , Rats , Rat Sprague-Dawley , Temps de réaction/physiologie , Récepteurs aux interleukines/antagonistes et inhibiteurs , Récepteurs purinergiques P2X3/effets des médicaments et des substances chimiques , Syndrome de l'articulation temporomandibulaire/complications , Syndrome de l'articulation temporomandibulaire/métabolisme , Syndrome de l'articulation temporomandibulaire/physiopathologie
4.
Biochemistry (Mosc) ; 76(11): 1262-9, 2011 Nov.
Article de Anglais | MEDLINE | ID: mdl-22117553

RÉSUMÉ

Insulin regulates glucose uptake into fat and skeletal muscle cells by modulating the translocation of GLUT4 between the cell surface and interior. We investigated a role for cortactin, a cortical actin binding protein, in the actin filament organization and translocation of GLUT4 in Chinese hamster ovary (CHO-GLUT4myc) and L6-GLUT4myc myotube cells. Overexpression of wild-type cortactin enhanced insulin-stimulated GLUT4myc translocation but did not alter actin fiber formation. Conversely, cortactin mutants lacking the Src homology 3 (SH3) domain inhibited insulin-stimulated formation of actin stress fibers and GLUT4 translocation similar to the actin depolymerizing agent cytochalasin D. Wortmannin, genistein, and a PP1 analog completely blocked insulin-induced Akt phosphorylation, formation of actin stress fibers, and GLUT4 translocation indicating the involvement of both PI3-K/Akt and the Src family of kinases. The effect of these inhibitors was even more pronounced in the presence of overexpressed cortactin suggesting that the same pathways are involved. Knockdown of cortactin by siRNA did not inhibit insulin-induced Akt phosphorylation but completely inhibited actin stress fiber formation and glucose uptake. These results suggest that the actin binding protein cortactin is required for actin stress fiber formation in muscle cells and that this process is absolutely required for translocation of GLUT4-containing vesicles to the plasma membrane.


Sujet(s)
Actines/métabolisme , Cortactine/métabolisme , Transporteur de glucose de type 4/métabolisme , Insuline/métabolisme , Protéines des microfilaments/métabolisme , Protéines proto-oncogènes c-akt/métabolisme , Fibres de stress/métabolisme , Cytosquelette d'actine/métabolisme , Androstadiènes/pharmacologie , Animaux , Cellules CHO , Membrane cellulaire/métabolisme , Cortactine/génétique , Cricetinae , Cytochalasine D/pharmacologie , Techniques de knock-down de gènes , Transporteur de glucose de type 4/génétique , Humains , Protéines des microfilaments/génétique , Fibres musculaires squelettiques/cytologie , Phosphorylation , Transport des protéines , Petit ARN interférent/génétique , Transduction du signal , Wortmannine , src-Family kinases/métabolisme
5.
Blood Cancer J ; 1(7): e29, 2011 Jul.
Article de Anglais | MEDLINE | ID: mdl-22829185

RÉSUMÉ

Aberrant activation of Janus kinase 2 (JAK2) caused by somatic mutation of JAK2 (JAK2V617F) or the thrombopoietin receptor (MPLW515L) plays an essential role in the pathogenesis of myeloproliferative neoplasms (MPNs), suggesting that inhibition of aberrant JAK2 activation would have a therapeutic benefit. Our novel JAK2 inhibitor, NS-018, was highly active against JAK2 with a 50% inhibition (IC(50)) of <1 n, and had 30-50-fold greater selectivity for JAK2 over other JAK-family kinases, such as JAK1, JAK3 and tyrosine kinase 2. In addition to JAK2, NS-018 inhibited Src-family kinases. NS-018 showed potent antiproliferative activity against cell lines expressing a constitutively activated JAK2 (the JAK2V617F or MPLW515L mutations or the TEL-JAK2 fusion gene; IC(50)=11-120 n), but showed only minimal cytotoxicity against most other hematopoietic cell lines without a constitutively activated JAK2. Furthermore, NS-018 preferentially suppressed in vitro erythropoietin-independent endogenous colony formation from polycythemia vera patients. NS-018 also markedly reduced splenomegaly and prolonged the survival of mice inoculated with Ba/F3 cells harboring JAK2V617F. In addition, NS-018 significantly reduced leukocytosis, hepatosplenomegaly and extramedullary hematopoiesis, improved nutritional status, and prolonged survival in JAK2V617F transgenic mice. These results suggest that NS-018 will be a promising candidate for the treatment of MPNs.

6.
J Appl Microbiol ; 103(6): 2291-8, 2007 Dec.
Article de Anglais | MEDLINE | ID: mdl-18045413

RÉSUMÉ

AIM: To evaluate the ability of high-energy ultraviolet A (UVA) light-emitting diode (LED) to inactivate bacteria in water and investigate the inactivating mechanism of UVA irradiation. METHODS AND RESULTS: We developed a new disinfection device equipped with high-energy UVA-LED. Inactivation of bacteria was determined by colony-forming assay. Vibrio parahaemolyticus, enteropathogenic Escherichia coli, Staphylococcus aureus and Escherichia coli DH5alpha were reduced by greater than 5-log(10) stages within 75 min at 315 J cm(-2) of UVA. Salmonella enteritidis was reduced greater than 4-log(10) stages within 160 min at 672 J cm(-2) of UVA. The formation of 8-hydroxy-2'-deoxyguanosine in UVA-LED irradiated bacteria was 2.6-fold higher than that of UVC-irradiated bacteria at the same inactivation level. Addition of mannitol, a scavenger of hydroxyl radicals (OH(*)), or catalase, an enzyme scavenging hydrogen peroxide (H(2)O(2)) to bacterial suspensions significantly suppressed disinfection effect of UVA-LED. CONCLUSION: This disinfection system has enough ability to inactivate bacteria and OH(*) and H(2)O(2) participates in the disinfection mechanism of UVA irradiation. SIGNIFICANCE AND IMPACT OF THE STUDY: We newly developed UVA irradiation system and found that UVA alone was able to disinfect the water efficiently. This will become a useful disinfection system.


Sujet(s)
Bactéries/effets des radiations , Désinfection , Rayons ultraviolets , Microbiologie de l'eau , Purification de l'eau/méthodes , Antioxydants/pharmacologie , Catalase/pharmacologie , Test clonogénique , Escherichia coli entéropathogène/effets des radiations , Escherichia coli/effets des radiations , Peroxyde d'hydrogène/antagonistes et inhibiteurs , Radical hydroxyle/antagonistes et inhibiteurs , Mannitol/pharmacologie , Staphylococcus aureus/effets des radiations , Vibrio parahaemolyticus/effets des radiations
7.
Lett Appl Microbiol ; 44(6): 649-53, 2007 Jun.
Article de Anglais | MEDLINE | ID: mdl-17576228

RÉSUMÉ

AIMS: To evaluate the effect of norepinephrine (NE) and related compounds on the growth of bacteria, we have examined the effect of the neuroendocrine hormone NE and related compounds on the growth of Vibrio parahaemolyticus and other human-pathogenic Vibrio species (Vibrio cholerae, Vibrio vulnificus, and Vibrio mimicus). METHODS AND RESULTS: The effects on bacterial growth were examined using the serum-based medium and viable cells were counted using agar plates. We have shown that NE and its related compounds stimulate growth of V. parahaemolyticus in serum-based medium. This NE-induced growth stimulation was dependent upon the presence of transferrin. NE also stimulated growth of V. mimicus, but not V. cholerae and V. vulnificus. CONCLUSIONS: These results suggest that the Vibrio species differ in their ability to respond to NE. SIGNIFICANCE AND IMPACT OF THE STUDY: It is possible that NE and related compounds modulate the pathogenicity of V. parahaemolyticus and V. mimicus.


Sujet(s)
Agonistes alpha-adrénergiques/pharmacologie , Catécholamines/pharmacologie , Norépinéphrine/pharmacologie , Vibrio/effets des médicaments et des substances chimiques , Vibrio/croissance et développement , Milieux de culture/composition chimique , Milieux de culture/pharmacologie , Transferrine/pharmacologie , Vibrio/pathogénicité , Virulence
8.
Aliment Pharmacol Ther ; 20 Suppl 1: 118-24, 2004 Jul.
Article de Anglais | MEDLINE | ID: mdl-15298617

RÉSUMÉ

BACKGROUND: Nitrates decrease the tone of the lower oesophageal sphincter, and may thus induce gastro-oesophageal reflux. AIM: In the present study, we evaluated electrogastrographic changes and heart-rate variability before and after the administration of nitrates. METHODS: In 15 patients with chest pain treated with nitrates, electrocardiography and percutaneous electrogastrography were performed before and after administration of nitrates. Autonomic nervous system function was evaluated by spectral analysis of heart-rate variability and serial changes in low frequency and high frequency power, and the low frequency/high frequency ratio were compared. Electrogastrograms were analysed by obtaining peak power amplitudes and their dominant frequencies. RESULTS: After the administration of nitrates (isosorbide dinitrate), high frequency power, an index of parasympathetic nervous activity, was significantly decreased, whereas the low frequency/high frequency ratio, an index of sympathetic nervous activity, was significantly increased. The mean peak amplitude of the electrogastrogram significantly increased postprandially both before and after treatment. After isosorbide dinitrate treatment, however, mean peak amplitudes after a meal were significantly lower than those obtained before treatment. The mean dominant frequency of the electrogastrogram did not vary before and after treatment. CONCLUSIONS: The present study suggests that nitrates inhibit gastrointestinal motility by decreasing autonomic nervous activity.


Sujet(s)
Système nerveux autonome/effets des médicaments et des substances chimiques , Motilité gastrointestinale/effets des médicaments et des substances chimiques , Dinitrate isosorbide/pharmacologie , Nitrates/pharmacologie , Donneur d'oxyde nitrique/pharmacologie , Sujet âgé , Douleur thoracique/traitement médicamenteux , Douleur thoracique/physiopathologie , Électrocardiographie ambulatoire , Électrophysiologie , Rythme cardiaque/effets des médicaments et des substances chimiques , Humains , Période post-prandiale , Analyse spectrale
9.
J Med ; 35(1-6): 187-99, 2004.
Article de Anglais | MEDLINE | ID: mdl-18084877

RÉSUMÉ

Mitral valve prolapse (MVP) is closely related to myocardial sympathetic nerve function. This study evaluated the presence of impaired myocardial sympathetic nerve function by Iodine-123-metaiodobenzylguanidine (MIBG) scintigraphy in ten patients with MVP. For comparison, 15 healthy subjects without heart disease were investigated (control group). Single photon emission computed tomography (SPECT) and anterior planar myocardial scintigraphy were performed 15 min (initial images) and 3 hours (delayed images) after injection of MIBG (111 MBq). The location and degrees of reduced tracer uptake were evaluated. Myocardial MIBG uptake was quantified by uptake ratio of the heart (H) to upper mediastinum (M) on the anterior planar images (H/M). Percentage washout of MIBG in nine sectors of all oblique slices along the short-axis was calculated. The washout rates were higher at the inferoposterior and septal segments in patients with anterior leaflet prolapse, and at inferoposterior and lateral segments in patients with posterior leaflet prolapse. The bull's eye map showed increased washout rate in the apical and posteroseptal basal segments. There was no significant difference in the H/M ratio between MVP patients and the control group. These results indicate that MIBG can be used to evaluate localized myocardial sympathetic nerve function in MVP.


Sujet(s)
3-Iodobenzyl-guanidine , Coeur/imagerie diagnostique , Coeur/innervation , Prolapsus de la valve mitrale/imagerie diagnostique , Radiopharmaceutiques , Système nerveux sympathique/physiopathologie , 3-Iodobenzyl-guanidine/administration et posologie , Adulte , Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Prolapsus de la valve mitrale/physiopathologie , Radiopharmaceutiques/administration et posologie , Système nerveux sympathique/imagerie diagnostique , Tomographie par émission monophotonique
10.
Endoscopy ; 34(8): 643-50, 2002 Aug.
Article de Anglais | MEDLINE | ID: mdl-12173086

RÉSUMÉ

BACKGROUND AND STUDY AIMS: Intraoperative changes in circulatory hemodynamics and autonomic nervous activity were evaluated in 33 patients with cholelithiasis who underwent laparoscopic cholecystectomy. PATIENTS AND METHODS: Of these patients, 18 were treated using a pneumoperitoneum (group G) and 15 using the abdominal wall-lifting method (group WL). Their ECG, blood pressure, arterial oxygen saturation, and expiratory carbon dioxide partial pressure were monitored. Autonomic nervous function was evaluated by spectral analysis of the heart rate. RESULTS: Mean blood pressure increased significantly in group G during surgery, but did not vary in group WL during any stage of surgery. The high-frequency (HF) power, an index of parasympathetic activity, decreased significantly in group G after pneumoperitoneum. However, the HF power did not decrease significantly in group WL. The LF/HF ratio, an index of sympathetic activity, increased significantly in group G after pneumoperitoneum, but did not vary in group WL. In addition, the incidence of ventricular or supraventricular arrhythmias and the severity of the arrhythmias as determined by Lown's classification were higher in group G than in group WL. These findings suggest that intraoperative changes in autonomic nervous activity, due to increased intra-abdominal pressure, were smaller in patients undergoing laparoscopic cholecystectomy using the abdominal wall-lifting method than in those undergoing laparoscopic cholecystectomy using pneumoperitoneum. The results also demonstrated that hemodynamic changes were smaller in patients undergoing the abdominal wall-lifting method than in those undergoing pneumoperitoneum. CONCLUSIONS: It was concluded that hemodynamics should be carefully monitored during pneumoperitoneum, and that the abdominal wall-lifting approach in laparoscopic cholecystectomy is a method worthy of consideration for elderly patients or those with cardiopulmonary complications.


Sujet(s)
Muscles abdominaux/chirurgie , Système nerveux autonome/physiologie , Pression sanguine/physiologie , Cholécystectomie laparoscopique/méthodes , Lithiase biliaire/chirurgie , Pneumopéritoine artificiel/méthodes , Sujet âgé , Sujet âgé de 80 ans ou plus , Lithiase biliaire/physiopathologie , Femelle , Humains , Période peropératoire , Mâle , Adulte d'âge moyen
11.
Aliment Pharmacol Ther ; 16 Suppl 2: 180-6, 2002 Apr.
Article de Anglais | MEDLINE | ID: mdl-11966539

RÉSUMÉ

BACKGROUND: Helicobacter pylori infection is involved in the formation of chronic peptic ulcer. However, a previously reported hypothesis concerning the involvement of central autonomic nervous disorder in this condition cannot be ruled out. AIM: To use spectrum analysis of heart rate viability to examine autonomic nervous activity before and after H. pylori eradication. METHODS: Twenty patients with chronic duodenal ulcer (duodenal ulcer group) and 20 age-matched normal adults (N group). In both groups, 24-h Holter electrocardiograms (ECGs) were recorded and spectrum analysis of heartrate variability was performed. In the duodenal ulcer group, Holter ECG was recorded before and after H. pylori eradication. RESULTS: In the N group, analysis of heart rate variability showed that high frequency (HF) power, an index of parasympathetic activity, was high at night, while the low frequency (LF)/HF ratio, an index of sympathetic function, was high during the daytime. In the duodenal ulcer group, HF power was higher at night than during the daytime, showing a similar pattern to the N group, but the power value was higher than in the N group (P < 0.05). In the duodenal ulcer group, LF/HF at night was significantly higher than that of the N group. In addition, in the duodenal ulcer group, autonomic activity after H. pylori eradication did not differ significantly from that before H. pylori eradication. CONCLUSIONS: In patients with chronic peptic ulcer, both sympatheticotonia and parasympatheticotonia may occur at night, and this abnormality in autonomic nervous activity may cause increased gastric acid secretion and gastric mucosal vasoconstriction. Abnormalities in autonomic activity persist even after H. pylori eradication, suggesting that they may be an independent risk factor in the formation of chronic peptic ulcer in addition to H. pylori infection.


Sujet(s)
Maladies du système nerveux autonome/complications , Ulcère duodénal/étiologie , Infections à Helicobacter/complications , Helicobacter pylori/isolement et purification , Maladies du système nerveux autonome/physiopathologie , Ulcère duodénal/physiopathologie , Femelle , Rythme cardiaque/physiologie , Infections à Helicobacter/traitement médicamenteux , Infections à Helicobacter/microbiologie , Infections à Helicobacter/physiopathologie , Helicobacter pylori/effets des médicaments et des substances chimiques , Humains , Mâle , Adulte d'âge moyen
12.
FEBS Lett ; 508(3): 484-8, 2001 Nov 23.
Article de Anglais | MEDLINE | ID: mdl-11728477

RÉSUMÉ

We recently showed that FliC of Salmonella enteritidis increased human beta-defensin-2 (hBD-2) expression, and now describe the signaling responsible pathway. FliC increased the intracellular Ca(2+) concentration ([Ca(2+)](in)) in Caco-2 cells. The [Ca(2+)](in) increase induced by FliC was prevented by U73122 and heparin, but not by chelating extracellular Ca(2+) or pertussis toxin. The FliC-induced increase in hBD-2 promoter activity via nuclear factor kappaB (NF-kappaB) was also inhibited by chelation of intracellular Ca(2+) or by U73122. We conclude that FliC increased [Ca(2+)](in) via inositol 1,4,5-trisphosphate, which was followed by up-regulating hBD-2 mRNA expression via an NF-kappaB-dependent pathway.


Sujet(s)
Flagelline/pharmacologie , Muqueuse intestinale/métabolisme , Salmonella enteritidis , bêta-Défensines/biosynthèse , bêta-Défensines/génétique , Cellules Caco-2 , Calcium/métabolisme , Noyau de la cellule/métabolisme , Chélateurs/pharmacologie , Côlon/métabolisme , Milieux de culture , Acide egtazique/pharmacologie , Oestrènes/pharmacologie , Héparine/pharmacologie , Humains , Inositol 1,4,5-trisphosphate/métabolisme , Facteur de transcription NF-kappa B/métabolisme , Toxine pertussique , Régions promotrices (génétique) , Pyrrolidones/pharmacologie , ARN messager/génétique , ARN messager/métabolisme , Transduction du signal , Régulation positive , Facteurs de virulence des Bordetella/pharmacologie
13.
J Virol ; 75(23): 11868-73, 2001 Dec.
Article de Anglais | MEDLINE | ID: mdl-11689668

RÉSUMÉ

A complete cDNA clone of the Newcastle disease virus (NDV) vaccine strain Hitchner B1 was constructed, and infectious recombinant virus expressing an influenza virus hemagglutinin was generated by reverse genetics. The rescued virus induces a strong humoral antibody response against influenza virus and provides complete protection against a lethal dose of influenza virus challenge in mice, demonstrating the potential of recombinant NDV as a vaccine vector.


Sujet(s)
Vecteurs génétiques , Virus de la maladie de Newcastle/génétique , Recombinaison génétique , Animaux , Anticorps antiviraux/biosynthèse , Lignée cellulaire , Embryon de poulet , Clonage moléculaire , ADN complémentaire , Données de séquences moléculaires , Virus de la maladie de Newcastle/croissance et développement , Virus de la maladie de Newcastle/pathogénicité
14.
Eur J Pharmacol ; 430(2-3): 359-67, 2001 Nov 02.
Article de Anglais | MEDLINE | ID: mdl-11711055

RÉSUMÉ

Hypertension often complicates type 2 diabetes mellitus, and angiotensin converting enzyme inhibitor treatment has been shown to improve insulin resistance in such cases. However, the effect of angiotensin II type-1 (AT(1)) receptor antagonists on insulin resistance is still controversial. To gain further information on this effect, we examined the effect of losartan on insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of type 2 diabetes mellitus. Losartan administration alone lowered systolic blood pressure, but did not improve oral glucose tolerance test or insulin resistance in OLETF rats. However, the administration of losartan with exercise significantly improved both systolic blood pressure and insulin resistance relative to control OLETF rats. On the other hand, losartan treatment, regardless of exercise, increased glucose uptake in excised soleus muscle and fat cells. To explore the beneficial effect of losartan on skeletal muscle glucose uptake, we examined intracellular signaling of soleus muscle. Although Akt activity and glucose transporter type 4 (GLUT4) expressions were not affected by losartan with or without exercise, extracellular signal-regulated kinase (ERK1/2) and p38 mitogen-activated protein (MAP) kinase activities were increased by both interventions. These results indicate that angiotensin AT(1) receptor antagonist improved local insulin resistance, but not systemic insulin resistance. These findings may explain the controversy over the effect of angiotensin AT(1) receptor antagonists on insulin resistance in clinical use. The enhancing effect of angiotensin AT(1) receptor antagonist on skeletal muscle glucose uptake may be attributable to MAP kinase activation or other mechanisms rather than phosphatidylinositol 3-kinase activation.


Sujet(s)
Antihypertenseurs/pharmacologie , Insulinorésistance , Losartan/pharmacologie , Protéines du muscle , Conditionnement physique d'animal/physiologie , Protein-Serine-Threonine Kinases , Adipocytes/effets des médicaments et des substances chimiques , Adipocytes/métabolisme , Animaux , Glycémie/effets des médicaments et des substances chimiques , Glycémie/métabolisme , Pression sanguine/effets des médicaments et des substances chimiques , Technique de Western , Poids/effets des médicaments et des substances chimiques , Désoxyglucose/pharmacocinétique , Diabète de type 2/métabolisme , Diabète de type 2/physiopathologie , Activation enzymatique/effets des médicaments et des substances chimiques , Glucose/pharmacocinétique , Glucose/pharmacologie , Hyperglycémie provoquée , Transporteur de glucose de type 4 , Rythme cardiaque/effets des médicaments et des substances chimiques , Insuline/sang , JNK Mitogen-Activated Protein Kinases , Mâle , Mitogen-Activated Protein Kinase 1/effets des médicaments et des substances chimiques , Mitogen-Activated Protein Kinase 1/métabolisme , Mitogen-Activated Protein Kinase 3 , Mitogen-Activated Protein Kinases/effets des médicaments et des substances chimiques , Mitogen-Activated Protein Kinases/métabolisme , Transporteurs de monosaccharides/effets des médicaments et des substances chimiques , Transporteurs de monosaccharides/métabolisme , Muscles squelettiques/effets des médicaments et des substances chimiques , Muscles squelettiques/métabolisme , Phosphorylation/effets des médicaments et des substances chimiques , Protéines proto-oncogènes/effets des médicaments et des substances chimiques , Protéines proto-oncogènes/métabolisme , Protéines proto-oncogènes c-akt , Rats , Rats de lignée OLETF , p38 Mitogen-Activated Protein Kinases
15.
Life Sci ; 69(15): 1709-15, 2001 Aug 31.
Article de Anglais | MEDLINE | ID: mdl-11665832

RÉSUMÉ

The relaxation effect of cilostazol, a phosphodiesterase III inhibitor, on the thoracic aorta was investigated. Cilostazol induced the relaxation of the thoracic aorta precontracted by phenylephrine in a concentration-dependent manner. The concentration-dependent relaxation was shifted to the right in the endothelium denuded aorta compared with that of intact endothelium, suggesting that this relaxation was partly dependent on endothelium. Cilostazol-induced relaxation of thoracic aorta tone was reversed by treatment with N(G)-nitro L-arginine (L-NNA), a competitive inhibitor of nitric oxide (NO) synthase. Cilostazol also significantly increased the NO level in the porcine thoracic aorta. In rats treated with cilostazol, the urinary excretion of nitrites, a stable metabolite of NO, and basal production of NO of the aortic ring were significantly greater than in those without treatment. These findings indicate that cilostazol-induced vasodilation of the rat thoracic aorta was dependent on the endothelium, which released NO from aortic endothelial cells.


Sujet(s)
3',5'-Cyclic-AMP Phosphodiesterases/antagonistes et inhibiteurs , Endothélium vasculaire/physiologie , Inhibiteurs de la phosphodiestérase/pharmacologie , Tétrazoles/pharmacologie , Vasodilatation/effets des médicaments et des substances chimiques , Vasodilatateurs/pharmacologie , Animaux , Aorte thoracique/effets des médicaments et des substances chimiques , Aorte thoracique/physiologie , Cilostazol , Techniques de culture , Cyclic Nucleotide Phosphodiesterases, Type 3 , Relation dose-effet des médicaments , Mâle , Monoxyde d'azote/biosynthèse , Nitrites/urine , Rats , Rats de lignée OLETF , Rat Sprague-Dawley
16.
Anesthesiology ; 95(3): 766-70, 2001 Sep.
Article de Anglais | MEDLINE | ID: mdl-11575552

RÉSUMÉ

BACKGROUND: Accumulating evidence suggests that mitochondrial rather than sarcolemmal adenosine triphosphate-sensitive K+ (K(ATP)) channels may have an important role in the protection of myocardium during ischemia. Because both lidocaine and mexiletine are frequently used antiarrhythmic drugs during myocardial ischemia, it is important to investigate whether they affect mitochondrial K(ATP) channel activities. METHODS: Male Wistar rats were anesthetized with ether. Single, quiescent ventricular myocytes were dispersed enzymatically. The authors measured flavoprotein fluorescence to evaluate mitochondrial redox state. Lidocaine or mexiletine was applied after administration of diazoxide (25 microM), a selective mitochondrial K(ATP) channel opener. The redox signal was normalized to the baseline flavoprotein fluorescence obtained during exposure to 2,4-dinitrophenol, a protonophore that uncouples respiration from ATP synthesis and collapses the mitochondrial potential. RESULTS: Diazoxide-induced oxidation of flavoproteins and the redox changes were inhibited by 5-hydroxydecanoic acid, a selective mitochondrial K(ATP) channel blocker, suggesting that flavoprotein fluorescence can be used as an index of mitochondrial oxidation mediated by mitochondrial K(ATP) channels. Lidocaine (10(-3) to 10 mM) and mexiletine (10(-3) to 10 mM) reduced oxidation of the mitochondrial matrix in a dose-dependent manner with an EC50 of 98+/-63 microM for lidocaine and 107+/-89 microM for mexiletine. CONCLUSIONS: Both lidocaine and mexiletine reduced flavoprotein fluorescence induced by diazoxide in rat ventricular myocytes, indicating that these antiarrhythmic drugs may produce impairment of mitochondrial oxidation mediated by mitochondrial K(ATP) channels.


Sujet(s)
Antiarythmiques/pharmacologie , Ventricules cardiaques/effets des médicaments et des substances chimiques , Lidocaïne/pharmacologie , Méxilétine/pharmacologie , Mitochondries du myocarde/effets des médicaments et des substances chimiques , Consommation d'oxygène/effets des médicaments et des substances chimiques , Adénosine triphosphate/pharmacologie , Animaux , Calcium/métabolisme , Diazoxide/pharmacologie , Mâle , Mitochondries du myocarde/métabolisme , Canaux potassiques/effets des médicaments et des substances chimiques , Rats , Rat Wistar
17.
J Nutr Sci Vitaminol (Tokyo) ; 47(3): 236-41, 2001 Jun.
Article de Anglais | MEDLINE | ID: mdl-11575579

RÉSUMÉ

Long-term enteral feeding by tube has become a frequently used procedure in elderly patients. However, only a few studies dealing with the nutritional assessment of such patients are currently available. This study was designed to clarify this issue. Anthropometric and biochemical variables, energy expenditure and dietary intake were investigated in 44 hospitalized bed-ridden patients with and without tube feeding over 65 years of age and 41 age-matched free-eating elders in a nursing home. All patients with tube feeding received enteral nutrition by nasogastric tube. The body weight, body mass index, mid-upper-arm circumference, arm muscle circumference and serum level of albumin were significantly lower in the patients with and without tube feeding, compared with free-eating elders of both genders (p<0.05). Energy intakes of the patients with tube feeding were 1,171+/-286 kcal/d (about 26 kcal/kg/d), which is comparable to the predicted total energy expenditure (1.2 x basal energy expenditure). Protein intake was 44.9+/-13.1 g/d (about 1.0 g/kg/d) and the percentage of protein per total energy was 15%. These intakes are generally considered to be optimal for bed-ridden patients receiving tube feeding. However, the incidence of protein-malnutrition, as evidenced by decreased arm muscle circumference (<80% of normal) and hypoalbuminemia (<35 g/L), in the patients with tube feeding was significantly higher than that in the healthy elders. In addition, the orally fed bed-ridden patients were also malnourished, suggesting that the bed-ridden patients easily became malnourished even if they were fed energy and protein which approximated calculated predicted values. These findings raise a problem concerning nutritional management of bed-ridden patients.


Sujet(s)
Nutrition entérale , État nutritionnel , Malnutrition protéinocalorique/épidémiologie , Sérumalbumine/analyse , Sujet âgé , Sujet âgé de 80 ans ou plus , Anthropométrie , Alitement , Études cas-témoins , Ration calorique , Métabolisme énergétique , Femelle , Hospitalisation , Humains , Incidence , Japon , Mâle , Évaluation de l'état nutritionnel , Besoins nutritifs , Malnutrition protéinocalorique/diagnostic
18.
Biochem Biophys Res Commun ; 286(5): 964-7, 2001 Sep 07.
Article de Anglais | MEDLINE | ID: mdl-11527394

RÉSUMÉ

We have suggested that a novel endothelin-1 with 31 amino acids [ET-1 (1-31)] plays an important role in fetal circulation, owing to a strong contractile activity on the umbilical artery. To clarify the pathophysiological significance of ET-1 (1-31) in the development of severe preeclampsia, its contractile activities on human umbilical arteries and uterine smooth muscle from patients with preeclampsia were studied. The contraction by ET-1 (1-31) was stronger in uterine smooth muscle of the patients with severe preeclampsia than that of normal subjects. On the contrary, the constriction of umbilical artery of the patients with eclampsia was significantly weaker than that of normal pregnant women. The stronger contraction of myometrium by ET-1 (1-31) in patients with severe preeclampsia observed for the first time in the present study suggests that ET-1 (1-31) might be involved in the development of preeclampsia.


Sujet(s)
Endothéline-1/composition chimique , Endothélines/composition chimique , Endothélines/pharmacologie , Muscles lisses/métabolisme , Fragments peptidiques/composition chimique , Fragments peptidiques/pharmacologie , Cordon ombilical/métabolisme , Utérus/métabolisme , Études cas-témoins , Relation dose-effet des médicaments , Femelle , Humains , Contraction musculaire , Pré-éclampsie/métabolisme , Grossesse
19.
Am J Surg ; 181(4): 356-61, 2001 Apr.
Article de Anglais | MEDLINE | ID: mdl-11438272

RÉSUMÉ

BACKGROUND: Peritoneal metastasis is the most frequent cause of death in patients with gastric cancer. Detection of free cancer cells in the peritoneal cavity at the time of surgery, therefore, is considered to be of great value in predicting the peritoneal recurrence and accordingly in the prognosis in patients with gastric cancer. This study examined the clinical significance of intraoperative determination of carcinoembryonic antigen (CEA) levels in peritoneal washes (pCEA) in patients with gastric cancer. METHODS: CEA levels in peritoneal washes were correlated retrospectively with several clinicopathologic factors including clinical outcome in 56 patients with resectable gastric cancer. RESULTS: Among several clinicopathologic factors, the depth of tumor invasion significantly and independently correlated with pCEA levels as revealed by multivariate stepwise logistic regression analysis. A significant difference in overall survival rates was observed between pCEA-positive and pCEA-negative groups: 5-year survival rates were 95.7% in pCEA-negative and 20% in pCEA-positive patients (P <0.0001). Multivariate analysis indicated that pCEA level is a statistically significant independent prognostic factor for the survival of patients with gastric cancer, and is an important factor for predicting peritoneal recurrence. CONCLUSIONS: pCEA could be a potential predictor of a poor prognosis as well as peritoneal recurrence in patients with gastric cancer. We believe that this information could contribute to determining the optimal intraoperative and postoperative therapeutic plan including adjuvant chemotherapy of gastric cancer.


Sujet(s)
Liquide d'ascite/composition chimique , Antigène carcinoembryonnaire/analyse , Tumeurs du péritoine/secondaire , Tumeurs de l'estomac/anatomopathologie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Analyse de variance , Liquide d'ascite/cytologie , Marqueurs biologiques tumoraux/analyse , Femelle , Humains , Modèles logistiques , Mâle , Adulte d'âge moyen , Lavage péritonéal , Tumeurs du péritoine/diagnostic , Pronostic , Études rétrospectives , Facteurs de risque , Sensibilité et spécificité , Tumeurs de l'estomac/mortalité , Taux de survie
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