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Biomedical subjects

Jun Watanabe

Publications and source records attributed to Jun Watanabe.

At least 55 records · Page 3Linked to original sources
PubMed2005

Utility of extracorporeal traction with nylon thread for easier vesicourethral anastomosis in laparoscopic prostatectomy.

PURPOSE: Vesicourethral anastomosis in laparoscopic prostatectomy is a very difficult procedure. Our purpose in this study was to evaluate a new method using extracorporeal bladder neck traction with nylon thread for vesicourethral anastomosis during laparoscopic radical prostatectomy. MATERIALS AND METHODS: A total of 10 patients underwent laparoscopic radical prostatectomy by this technique, and we evaluated anastomosis time, operative time, and postoperative status of vesicourethral anastomosis. RESULTS: It was possible to shorten both anastomosis time and operative time by this procedure, and to obtain a hermetic anastomosis without higher risk of incontinence, stricture, or leakage. CONCLUSIONS: Extracorporeal bladder neck traction with nylon thread is a very useful procedure to carry out easier vesicourethral anastomosis, especially for a surgeon's initial experience in laparoscopic radical prostatectomy.

Anastomosis, Surgical↗
PubMed2005

Idiopathic left ventricular tachycardia originating from the mitral annulus.

BACKGROUND: Radiofrequency catheter ablation (RFCA) can eliminate most idiopathic repetitive monomorphic ventricular tachycardias (RMVTs) originating from the right and left ventricular outflow tracts (RVOT, LVOT). Here, we describe the electrophysiological (EP) findings of a new variant of RMVT originating from the mitral annulus (MAVT). METHODS AND RESULTS: MAVT was identified in 35 patients out of 72 consecutive left ventricular RMVTs from May 2000 to June 2004. All patients underwent an EP study and RFCA. The sites of origin of the MAVT were grouped into four groups according to the successful ablation sites around the mitral annulus. Group I included the anterior sites (n = 11), group II the anterolateral sites (n = 9), group III the lateral sites (n = 6), and group IV the posterior sites (n = 9). The MAVTs were a wide QRS tachycardia with a delta wave-like beginning of the QRS complex. The transitional zone of the R wave occurred between V1-V2 in all cases. The 12-lead electrocardiogram (ECG) pattern might reflect the site of the origin of MAVTs around the mitral annulus. We proposed an algorithm for predicting the site of the focus and the tactics needed for successful RFCA of the MAVT. CONCLUSIONS: We described the EP findings of the new variant of RMVT, MAVT. Most MAVTs could be eliminated by RF applications to the endocardial mitral annulus using our proposed tactics.

Adolescent↗
PubMed2005

Monophasic action potential duration at the crista terminalis in patients with sinus node disease.

BACKGROUND: The repolarization properties of the crista terminalis (CT) cells have not been elucidated in patients with sinus node disease (SND). In the present study a new technique of recording the monophasic action potential (MAP) at the CT was used to examine the repolarization of the right atrium (RA) in SND patients. METHODS AND RESULTS: Symptomatic SND (n=13) patients and age-, sex-matched control patients (n=13) were tested. The MAP duration (MAPD) at a basic cycle length of 600 ms was recorded at the CT in the superior vena cava - RA junction and at the middle - anterior RA with the effective refractory period (ERP) at the high RA. In 6 controls and 4 SND patients, the effect of adenosine triphosphate on the MAPD was examined. The MAPD at the CT exceeded that at the middle - anterior RA in both groups. The MAPD at the CT in the SND group was significantly prolonged compared with the control group (CT: 358+/-39 ms vs 289+/-43 ms). Between the SND and control groups, the MAPD at the middle - anterior RA (278+/-36 ms vs 265+/-39 ms) and ERP (294+/-42 ms vs 266+/-41 ms) did not differ. Both the corrected-sinus node recovery time and sinoatrial conduction time were better correlated with the MAPD at the CT than the MAPD at the middle - anterior RA and ERP. Adenosine triphosphate shortened the MAPD, which was augmented at the CT in the SND patients. CONCLUSION: A novel method of estimating the MAP at the CT revealed the characteristics of atrial repolarization in SND patients.

Action Potentials↗
PubMed2005

Portopulmonary hypertension: hemodynamics, pulmonary angiography, and configuration of the heart.

BACKGROUND: The goal of the present study was to examine the cardiac configuration and pulmonary vascular changes in patients with portopulmonary hypertension (PPHTN) and compare them with those of idiopathic pulmonary arterial hypertension (IPAH). METHODS AND RESULTS: The subjects were 10 patients with PPHTN and 18 with IPAH. In PPHTN, the increases in the right ventricular end-diastolic volume index (89+/-19 vs 128+/-50 ml/m2; p=0.04), right end-systolic volume index (50+/-19 vs 95+/-47 ml/m 2; p=0.02) and right ventricular mass index (47+/-18 g/m2 vs 79+/-31; p=0.04) were low compared with IPAH. The decrease in the right ventricular ejection fraction was also low in PPHTN (45+/-10 vs 28+/-13%; p=0.01). The degree of sparse arborization and abrupt narrowing on wedged pulmonary angiography was moderate in PPHTN compared with IPAH. In PPHTN, the proximal pulmonary arteries were dilated near the segmental arteries, which were narrow in IPAH. CONCLUSION: Changes in the configuration of the heart were moderate in PPHTN compared with those in IPAH. The degree of sparse arborization and abrupt narrowing were also moderate in PPHTN.

Adult↗
PubMed2005

Poor prognosis of Japanese patients with chronic heart failure following myocardial infarction--comparison with nonischemic cardiomyopathy.

BACKGROUND: Myocardial infarction (MI) is one of the major etiologies of chronic heart failure (CHF) in Japan. METHODS AND RESULTS: The prognoses of CHF patients after MI (n=283) were investigated by comparing them with those of CHF patients with nonischemic cardiomyopathy (NICM, n=310) from the CHF registry (CHART; n=1,154). The Kaplan-Meier (KM) analyses revealed that the 3-year all-cause mortality was significantly higher in the MI cohort compared with the NICM cohort (29.0% vs 12.4%, p<0.0005). Age/gender/treatment-adjusted KM analysis revealed significant differences only in the cohorts with preserved left ventricular ejection fraction (LVEF), defined as LVEF >45%, or in less symptomatic patients (New York Heart Association I or II). Multivariate Cox regression analysis showed that beta-blocker (BB) was associated with a significant reduction in mortality from cardiac causes, and either angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (ACEI/ARB) was significantly related to the improvement of survival in the MI cohort (adjusted hazard ratio: 0.222 and 0.497, p<0.05), even though these medicines were used significantly less often in the MI cohort. CONCLUSIONS: Underlying MI has a significant impact on the survival of Japanese CHF patients, especially those with preserved LVEF or with fewer symptoms. The appropriate expansion of ACEI/ARB or BB therapy might be necessary to improve their survival.

Adrenergic beta-Antagonists↗
PubMed2005

Efficacy of acute inhalation of nitric oxide in patients with primary pulmonary hypertension using chronic use of continuous epoprostenol infusion.

BACKGROUND: There have only been a few reports published on combination therapy for patients with primary pulmonary hypertension (PPH). METHODS AND RESULTS: Fifteen patients with PPH (4 men and 11 women, 34.5+/-12.1 years old) had received chronic administration of epoprostenol and the additive effects of inhaled nitric oxide (NO) and the hemodynamic changes were evaluated. In addition, the difference in the effect of acute NO loading before and after the epoprostenol therapy was compared in 6 of these patients. Under chronic use of epoprostenol, mean pulmonary arterial pressure, mean right atrial pressure and pulmonary vascular resistance were decreased with acute inhalation of NO. However, cardiac output, mean aortic pressure and systemic vascular resistance were unchanged. As a result, the pulmonary to systemic vascular resistance ratio was reduced. Moreover, after chronic use of epoprostenol, the change (delta) in cardiac output with NO inhalation was increased and the NO-induced decrease in pulmonary vascular resistance was augmented compared to those before the induction. CONCLUSION: Nitric oxide inhalation further improved the hemodynamics when combined with chronic use of epoprostenol in PPH patients. These results suggest the possibility that combination therapies can be used in the treatment for PPH patients.

Administration, Inhalation↗
PubMed2005

Effect of nifekalant, a class III anti-arrhythmic agent, on Ca2+ waves in rat intact trabeculae.

BACKGROUND: Nifekalant, a class III anti-arrhythmic agent, has been used clinically at serum concentrations of 1-10 micromol/L in patients with ventricular arrhythmias. However, the effect of nifekalant on triggered arrhythmias has not yet been established. METHODS AND RESULTS: Trabeculae were dissected from the right ventricles of 16 rat hearts. The force was measured using a silicon strain gauge, the membrane potential using ultra-compliant microelectrodes, and the regional intracellular Ca2+ ([Ca2+]i) using electrophoretically microinjected fura-2 and an image intensified CCD camera at a sarcomere length of 2.1 microm. Rapid cooling contractures (RCCs) were measured to estimate the Ca2+ content in the sarcoplasmic reticulum. Ca2+ waves and aftercontractions were measured after the induction of reproducible Ca2+ waves. Nifekalant at 1, 10 and 250 micromol/L increased significantly the action potential duration, the peak [Ca2+]i, the developed force and the amplitude of RCCs in a concentration-dependent manner (stimulus interval = 2 s, [Ca2+]o = 0.7 mmol/L, 26.0+/-0.2 degrees C). Nifekalant at 10 and 250 micromol/L increased significantly the velocity of Ca2+ waves with an enhancement of the aftercontractions (stimulus interval = 0.5 s for 7.5 s, [Ca2+]o = 1.8+/-0.1 mmol/L, 22.3+/-0.5 degrees C). CONCLUSIONS: Nifekalant, even at a therapeutic concentration, can increase muscle contraction, but may worsen triggered arrhythmias because of the acceleration of Ca2+ waves under Ca2+-overloaded conditions.

Animals↗
PubMed2005

Initial presentation and fatal complications of linear IgA bullous dermatosis in the larynx and pharynx.

Two cases of linear IgA bullous dermatosis initially presenting as ulcerative lesions in the larynx and pharynx are reported. It was difficult to diagnose and treat the lesions, but they were finally diagnosed from the histopathological findings of accompanying skin lesion specimens. One of the patients required a tracheostomy due to increased airway stenosis by a laryngeal lesion. Despite general corticosteroid administration this could not be completely resolved, although partial opening of the glottis was observed, and the patient died of accidental tracheostomy tube complications during home care. Although there are no reports of this disease in the otolaryngological field, these rare diseases involving the skin and entire body should be considered in the differential diagnosis of laryngeal and pharyngeal ulcerative lesions, including airway stenosis. Furthermore, simple and safe procedures for relieving airway stenosis should be selected for rare and difficult-to-diagnose airway disease, prior to the final diagnosis.

Aged↗
PubMed2005

Coumarin and flavone derivatives from estragon and thyme as inhibitors of chemical mediator release from RBL-2H3 Cells.

Estragon and thyme extracts showed potent inhibitory activities against chemical mediator release from rat basophilic leukemia RBL-2H3 cells. 7-Methoxycoumarin was isolated from estragon, and 5,4'-dihydroxy-6,7,3'-trimethoxyflavone, 5,4'-dihydroxy-6,7,8,3'-tetramethoxyflavone, 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone and luteolin were isolated from thyme as active components. Structure-activity relationship studies among the active isolates and their related compounds indicated that the oxygen-containing functional group at the 7-position of the coumarin structure was advantageous for the inhibitory activity and that methylation of the hydroxyl group at the 4'-position of the flavone structure was disadvantageous. It was also found that coumarin derivatives inhibited an earlier step than intracellular calcium release and proteinkinase C activation, while flavones inhibited a later step or both earlier and later steps.

Animals↗
PubMed2005

Formation of biocompatible nanoparticles by self-assembly of enzymatic hydrolysates of chitosan and carboxymethyl cellulose.

A simple preparation method for biocompatible nanoparticles in high concentration (0.5 wt %) by self-assembly of chitosan and carboxymethyl cellulose hydrolysates was developed. Chitosan and carboxymethyl cellulose were hydrolyzed beforehand with chitosanase and cellulase respectively to make fragments having lower molecular weights. Nanoparticles were spontaneously formed only by mixing the two hydrolysate solutions. The particle size distribution was relatively narrow, about 200 nm in mean size. The mean particle size decreased from 226 nm to 165 nm with decreasing molecular weight of chitosan hydrolysate from 9.5 to 6.8 kDa. The mixing ratio of chitosan and carboxymethyl cellulose hydrolysates also affected particle size. Changes in particle size are discussed in relation to a possible mechanism of polyionic complexation. The chitosan-carboxymethyl cellulose nanoparticles were stably suspended over 1 week even under low pH (pH 3.0), high ionic strength (NaCl 1 M), or low temperature (4 degrees C) conditions.

Bacillus↗
PubMed2005

Primary screening of relatively less allergenic wheat varieties.

Since the number of wheat-allergic patients has been increasing in recent years, less allergenic wheat varieties are socially demanded. The aim of this study was to primarily screen 324 varieties of wheat picked up from various parts of the world. Prior to the screening, the inhibition ELISA (enzyme-linked immunosorbent assay) was examined with major wheat allergens (glutenin, gliadin and alpha-amylase inhibitor). As a result, the patient's IgE antibodies used in this assay reacted to these three allergens, and thereby turned out to be suitable for the primary screening for the less allergenic wheat varieties. Thus, the allergenicity of each wheat sample was measured by direct ELISA using the sole patient's serum as an IgE source and 'Aoba Komugi' as a control (a value of 1.0). The mean +/- SD of all kinds was 1.14 +/- 0.37. Among them, 'CM32859' (Mexico) gave the lowest value (0.38). Several other varieties, such as 'Einkorn' (Unknown), 'Iliniaza' (Ecuador), 'Hsin Mai 2' (China), 'Italy 1' (Italy) and so on, also serve as candidates for the less allergenic varieties. More detailed secondary screening will lead to a finding of the less allergenic wheat varieties for wheat-allergic patients, because these varieties are expected to become mother plants for breeding.

Allergens↗
PubMed2005

Myocardial 11C-diacylglycerol accumulation and left ventricular remodeling in patients after myocardial infarction.

UNLABELLED: Left ventricular (LV) remodeling after myocardial infarction (MI) is a maladaptive process that increases the risk of heart failure and death. The myocardial phosphoinositide cycle, which is located downstream from several neurohumoral factors, plays a crucial role in LV remodeling. Our animal studies demonstrated that 1-[1-11C]butyryl-2-palmitoyl-rac-glycerol (11C-DAG) can be used to visualize regions with an activated phosphoinositide cycle. Therefore, we examined whether myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement and systolic dysfunction in post-MI patients. METHODS: We performed PET with 11C-DAG in 13 post-anteroseptal MI patients and 4 healthy volunteers. We placed regions of interest on the noninfarcted myocardium and calculated the myocardium-to-left atrial (LA) chamber ratio of 11C-DAG accumulation. RESULTS: The myocardium-to-LA chamber ratio of 11C-DAG was significantly higher in the post-MI patients (mean +/- SD, 1.73 +/- 0.35) compared with that of the healthy volunteers (mean +/- SD, 1.25 +/- 0.13; P < 0.05). In the post-MI patients, the myocardium-to-LA chamber ratio of (11)C-DAG was significantly correlated with the LV end-diastolic volume index (r = 0.79, P < 0.01) and the plasma concentration of brain natriuretic peptide (r = 0.85, P < 0.001) and negatively correlated with the LV ejection fraction (r = -0.69, P < 0.01). CONCLUSION: These findings suggest that the myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement, LV systolic dysfunction, and humoral activation in post-MI patients. This new imaging strategy based on intracellular signaling may contribute to the assessment and treatment of post-MI patients.

Adult↗
PubMed2004

Effect of pituitary adenylate cyclase-activating polypeptide 38 (PACAP38) on tissue oxygen content--treatment in central nervous system of mice.

It has been reported that pituitary adenylate cyclase-activating polypeptide (PACAP) plays an important role in preventing neuronal cell death and is also a potent vasodilator. Cerebral hypotension and hypoperfusion during cerebral ischemia and neurodegenerative diseases are well known as some of the negative factors which aggravate neuronal cell death. Nevertheless, the effect of PACAP on the cerebral circulation was not understood well. Therefore, in the present study, we determined the mean arterial blood pressure (MBP), regional cerebral blood flow (rCBF) and cerebral oxygen content (pO2) in mice, and estimated the therapeutically useful doses of PACAP. Under barbiturate anesthesia, polyethylene tubes were inserted into mice to monitor MBP and to administer PACAP (5 x 10(-13)-5 x 10(-8) mol/kg) or vasoactive intestinal peptide (VIP; 5 x 10(-12) and 5 x 10(-9) mol/kg). Then, MBP, rCBF and cerebral pO2 were simultaneously measured in the mice. PACAP (5 x 10(-10)-5 x 10(-9) mol/kg) injections transiently decreased MBP, and cerebral pO2. PACAP (5 x 10(-8) mol/kg) injections produced a long-lasting potent decline of MBP, rCBF and cerebral pO2. Therefore, PACAP should be applied at low doses which do not influence the MBP and cerebral circulation to determine the therapeutically useful doses of PACAP for neuroprotection.

Animals↗
PubMed2004

MexAB-OprM specific efflux pump inhibitors in Pseudomonas aeruginosa. Part 3: Optimization of potency in the pyridopyrimidine series through the application of a pharmacophore model.

The addition of substituents to the pyridopyrimidine scaffold of MexAB-OprM specific efflux pump inhibitors was explored. As predicted by a pharmacophore model, the incorporation substituents at the 2-position improved potency. Piperidines were found to be optimal, and further introduction of polar groups without compromising the activity was shown to be feasible. Careful positioning of the essential acidic moiety of the pharmacophore relative to the scaffold led to the discovery of vinyl tetrazoles with still greater potency.

Bacterial Outer Membrane Proteins↗
PubMed2004

The production of hypoallergenic wheat flour and the analysis of its allergy suppressive effects.

We propose a novel method to produce hypoallergenic wheat flour suitable for patients allergic to wheat by using enzymatic fragmentation with cellulase and actinase. The hypoallergenic flour displayed potent inhibitory activity against allergen absorption and actively suppressed allergic reactions, probably inducing oral tolerance. The results suggest that hypoallergenic wheat flour has allergy-suppressive effects without inducing side effects.

Cellulase↗
PubMed2004

Clinical outcome of a large-scale multi-institutional retrospective study for locally advanced bladder cancer: a survey including 1131 patients treated during 1990-2000 in Japan.

OBJECTIVE: We conducted a multi-institutional analysis to establish the contemporary clinical outcome of invasive bladder cancer treated with radical cystectomy in Japan. METHODS: A total of 1131 consecutive patients who underwent radical cystectomy for invasive bladder cancer between January 1990 and December 2000 at 32 hospitals were retrospectively analyzed. RESULTS: Histopathological analysis demonstrated that 1042 patients (92.1%) harbored transitional cell carcinomas (TCCs), whereas 89 patients (7.9%) presented non-TCCs, including squamous cell carcinoma and adenocarcinoma. Pelvic lymphadenectomy was performed in 1013 patients in total, and pathologically confirmed lymph node metastases were found in 162 (16.0%). The overall survival at 5 years was 68.0% and most deaths (79.0%) occurred within 3 years. Multivariate analysis demonstrated that gender, clinical stage, pathological stage, lymph node involvement and lymph node dissection were the independent predictive factors for survival, whereas histological type, sex and grade had no significant impact on survival. CONCLUSIONS: These clinical results demonstrate that radical cystectomy with lymph node dissection results in good survival for invasive bladder cancer, providing standard data with which other forms of therapy can be compared.

Adult↗
PubMed2004

Synthesis and structural characterization of silver(I), aluminium(III) and cobalt(II) complexes with 4-isopropyltropolone (hinokitiol) showing noteworthy biological activities. Action of silver(I)-oxygen bonding complexes on the antimicrobial activities.

Through two unequivalent oxygen donor atoms of the hinokitiol (Hhino; C10H12O2; 4-isopropyltropolone) ligand that showed noteworthy biological activities, the dimeric, silver(I)-oxygen bonding complex [Ag(hino)]2 1, the monomeric aluminium(III) complex [Al(hino)3].0.5H2O 4 and the cobalt(II) complex "[Co(hino)2]2.H2O" 6 were synthesized and characterized with elemental analysis, thermogravimetric and differential thermal analysis (TG/DTA), FTIR and solution (1H and 13C) NMR spectroscopy. The crystal structure of 1 was determined by Rietveld analysis based on X-ray powder diffraction (XPD) data and those of [Al(hino)3].MeOH 4a and [Co(hino)2(EtOH)]2 6a, being obtained as yellow block crystals and red platelet crystals, respectively, by crystallization of 4 and 6, were determined by single-crystal X-ray analysis. The antimicrobial activities of 1, 4 and 6, evaluated with minimum inhibitory concentration (MIC; microg ml(-1)), were compared with those of other metal complexes (M=Na, Li, Cs, Ca, V, Zn) with the hino- ligand. The antimicrobial activities observed in the alkali-metal salts strongly suggested that they were attributed to the effect of the anionic hino- species. The antimicrobial activities of 1 were significantly enhanced, whereas those of other metal complexes were suppressed, compared with those of the neutral Hhino and anionic hino- molecules. The antimicrobial activities observed in 1 were comparable with those of other recently found silver(I)-oxygen bonding complexes, the ligands of which had no activity. Thus, it is proposed that the antimicrobial activities of the silver(I)-oxygen bonding complexes are due to a direct interaction or complexation of the silver(I) ion with biological ligands such as protein, enzyme and membrane, and the coordinating ligands of the silver(I) complexes play the role of a carrier of the silver(I) ion to the biological system.

Aluminum↗