Biomedical subjects

Y Watanabe

Publications and source records attributed to Y Watanabe.

At least 73 records · Page 4Linked to original sources

PubMed2003

Hepatocyte growth factor and c-Met (HGF/c-Met) in adenoid cystic carcinoma of the human salivary gland.

BACKGROUND: Hepatocyte growth factor (HGF) enhances cell growth, morphogenesis, and scattering of various epithelial cells. The aim of this study was to evaluate the hypothesis that HGF/c-Met plays a biological role in the invasive growth of adenoid cystic carcinoma (ACC). METHODS: Immunohistochemically, expression of HGF and its receptor c-Met was examined in 15 cases of ACC. To examine the direct effects of HGF on ACC, cell line derived from of ACC (ACC3) was used. The expression of HGF and c-met in ACC3 was investigated by RT-PCR. Analysis of mechanisms of invasion was done by performing scattering assay and matrigel invasion chamber assay. RESULTS: Positive staining of HGF was found in all cases, and that of c-Met was 67%. In ACC3, c-met was expressed, but not HGF. Stimulation of ACC3 by rhHGF induced scattering and promoted invasion. CONCLUSION: The present results suggest that HGF/c-Met increases tumor cell scattering and may play a part in invasiveness of ACC.

Carcinoma, Adenoid Cystic↗

PubMed2003

Neuronal mechanism of nociceptin-induced modulation of learning and memory: involvement of N-methyl-D-aspartate receptors.

Nociceptin (also called orphanin FQ) is an endogenous heptadecapeptide that activates the opioid receptor-like 1 (ORL1) receptor. Nociceptin system not only affects the nociception and locomotor activity, but also regulates learning and memory in rodents. We have previously reported that long-term potentiation and memory of ORL1 receptor knockout mice are enhanced compared with those in wild-type mice. Here, we show the neuronal mechanism of nociceptin-induced modulation of learning and memory. Retention of fear-conditioned contextual memory was significantly enhanced in the ORL1 receptor knockout mice without any changes in cued conditioned freezing. Inversely, in the wild-type mice retention of contextual, but not cued, conditioning freezing behavior was suppressed by exogenous nociceptin when it was administered into the cerebroventricle immediately after the training. ORL1 receptor knockout mice exhibited a hyperfunction of N-methyl-D-aspartate (NMDA) receptor, as evidenced by an increase in [3H]MK-801 binding, NMDA-evoked 45Ca2+ uptake and activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity and its phosphorylation as compared with those in wild-type mice. The NMDA-induced CaMKII activation in the hippocampal slices of wild-type mice was significantly inhibited by exogenous nociceptin via a pertussis toxin-sensitive pathway. However, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor GluR1 subunit at Ser831 and Ser845, and NMDA receptor subunit NR2B at Thr286 were phosphorylated similarly after NMDA receptor stimulation in both type of mice. The expressions of GluR1 and GluR2 also did not change, but the levels of polysialylated form of neuronal cell adhesion molecule (N-CAM) were reduced in the ORL1 receptor knockout as compared with wild-type mice. These results suggest that nociceptin system negatively modulates learning and memory through the regulation of NMDA receptor function and the expression of N-CAM.

Animals↗

PubMed2003

Propagation of surface plasmon polariton in nanometre-sized metal-clad optical waveguides.

Using a local anodic-oxidation method with a probe tip of a scanning near-field optical microscope (SNOM) as the electrode, we have fabricated an oxide core with subwavelength dimensions on metal. The propagation of the surface plasmon polariton (SPP), which is excited at the interface between the oxide core and the metal clad, has been investigated using the same SNOM. Altering the wavelength of input light from 532 nm to 830 nm, the propagation length of the SPP extends from 2 micro m to 6 micro m. We carried out a simulation of the SPP propagation, and obtained a similar wavelength dependence.

Journal Article↗

PubMed2003

NOx (nitrite/nitrate) in cerebral spinal fluids obtained from patients with influenza-associated encephalopathy.

It has become evident that the number of patients with a new type of influenza-associated encephalopathy is increasing in Japan. Nitric oxide (NO), a simple free radical gas, elicits a wide range of physiological and pathophysiological effects. We measured the nitrite/nitrate (NO x ) levels in cerebral spinal fluid obtained from patients with influenza-associated encephalopathy in order to evaluate the correlation between the NO production and the process of influenza-associated encephalopathy. Fifteen children were enrolled, aged from 1 to 9 years. As control we used 14 cerebral spinal fluids obtained from patients with urinary tract infection, respiratory infection or mumps meningitis without any sequela. NO 3 in influenza-associated encephalopathy was significantly higher than that of control group. On the other hand NO 2 was not significantly higher than that of control group. In particular, 4 out of 5 fatal cases revealed high NO 2 or NO 3. One case having normal levels in NO 2 and NO 3 showed that NH 3 was high. These results revealed that NO plays a role in influenza-associated encephalopathy through indirect effects of NO.

Brain↗

PubMed2003

Cigarette smoking and alcohol consumption associated with gastro-oesophageal reflux disease in Japanese men.

BACKGROUND: Associations between lifestyle factors and gastro-oesophageal reflux disease (GORD) have been conflicting. We aimed to examine these associations in Japanese men. METHODS: We performed a cross-sectional study of Japanese male workers who visit a clinic for a routine health check-up and asked them to fill out a self-report questionnaire. Logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for GORD, defined as heartburn and/or acid regurgitation at least twice weekly. RESULTS: Of the 4095 eligible subjects, 276 (6.7%) were diagnosed as having GORD. Current smoking was significantly associated with CORD compared with non-smoking (OR = 1.35, 95% CI, 1.01-1.82). Moderate drinking (16-37 mL/day) and heavy drinking (> or = 38 mL/day) were also associated with GORD, while age and body mass index were not. After adjustment for age, daily alcohol consumption and body mass index, an increase in number of pack-years of cigarette smoking was significantly associated with an increased OR of GORD (P for trend = 0.034), and the OR for persons whose number of pack-years of cigarette smoking was more than 20.1 was 1.45 (CI 1.04-2.04) compared with non-smokers. CONCLUSION: Cigarette smoking and alcohol consumption are associated with an increased odds ratio for GORD in Japanese men.

Adult↗

PubMed2003

Validation and verification of the ICRP biokinetic model of 32P: the criticality accident at Tokai-Mura, Japan.

Regrettably, a criticality accident occurred at a uranium conversion facility in Tokai-mura, Ibaraki, Japan, on 30 September 1999. Radioactivities of 32P in urine, blood and bone samples of the victims, who were severely exposed to neutrons, were measured. 32P was induced in their whole bodies at the moment of the first nuclear release by the reaction 31P (n, gamma) 32P and 32S (n, p) 32P. A realistic biokinetic model was assumed, as the exchange of 32P between the extracellular fluid compartment and the soft tissue compartment occurs only through the intracellular compartment, and the model was used for preliminary calculations. Some acute excretion of 32P, caused by decomposition or elution of tissues which occurred at the time of the accident, may have happened in the victims' bodies in the first few days. The working hypotheses in the present work should initiate renewed discussion of 32P biokinetics.

Bone and Bones↗

PubMed2003

Biokinetics of radiotellurium in rats.

Radiotellurium is present in the environment primarily due to its release during nuclear reactor accidents. Little is known of tellurium metabolism in juveniles, although the element is relatively abundant and has a number of industrial uses. A biokinetic study of radiotellurium in rats was performed using gamma-ray counting. Wistar strain rats were used to determine the uptake of H2(123m)TeO3 by the whole-body retention of juvenile rats and the conceptus in relation to its gestational stages, by measurements in the placenta, fetal membranes, fetal fluid and fetus. The whole-body retention of 123mTe in juvenile rats was higher than that of adult rats. The relative concentration in the placenta and fetal membranes was higher than in the fetus. No activity was observed in the fetal fluid. These results indicate that the placenta and fetal membranes play significant roles as barriers to the transfer of 123mTe into the fetus. The ratio, relative concentration in fetus/relative concentration in mother (C(F)/C(M)), was calculated. The C(F)/C(M) ratio was dependent on the stage of gestation and ranged from 0.2 to 0.5. A little 123mTe was transferred to the suckling rats through the mother's milk when the isotope was administered intravenously to the mother.

Administration, Oral↗

PubMed2003

Occlusal and TMJ loads in subjects with experimentally shortened dental arches.

To determine whether shortened dental arches (SDAs) cause functional overloading of the teeth and the temporomandibular joints, which has been implicated in periodontal diseases and temporomandibular disorders, we investigated the influences of SDA on occlusal and joint loads. Bite force and masticatory muscle electromyograms were recorded in five dentate subjects who clenched maximally on intra-oral appliances, creating symmetrical SDAs experimentally. Muscular forces estimated from the recorded electromyograms were fed into a finite element jaw model for calculating bite forces and joint loads. Comparison between the measured and the calculated bite forces ensured that the joint loads were representative. The bite force on each tooth increased with missing molar occlusions, while joint loads decreased. The bite force per root surface area was always greatest on the most posterior tooth, and these values were most constant. The findings provide no evidence that SDA causes overloading of the joints and the teeth, which suggests that neuromuscular regulatory systems are controlling maximum clenching strength under various occlusal conditions.

Adaptation, Physiological↗

PubMed2003

Concentrations of sialyloligosaccharides in bovine colostrum and milk during the prepartum and early lactation.

Sialyloligosaccharides and sialylglycoconjugates in colostrum and milk are regarded to be important biological components with respect to be source of brain gangliosides in infant and to be antiinfectional components for the attack by the pathogenic bacteria and virus. Several acidic oligosaccharides have been characterised in both bovine and human milk or colostrum. The sialyloligosaccharide content of human colostrum and milk has been extensively studied, whereas that of cows milk and colostrum has received less attention. In this study, the concentrations of three sialyloligosaccharides of bovine colostrum and milk were determined at various stages during the prepartum and the first 7 d postpartum. The concentration of 3'SL (Neu5Ac(alpha2-3)Gal(beta1-4)Glc) reached a maximum value of 0.85 mg/ml immediately following parturition while the concentrations of 6'SL (Neu5Ac(alpha2-6)Gal(beta1-4)Glc) and 6'SLN (Neu5Ac(alpha2-6)Gal(beta1-4)GlcNAc) of 0.14 and 0.12 mg/ml, respectively, were much lower at this initial stage, although these concentration were maximum immediately following parturition. Bovine colostrum, especially that collected immediately after parturition, may be suitable as a source of 3'SL and other sialyloligosaccharides for use as additives by the food or pharmaceutical industries.

Animals↗

PubMed2003

Successful perioperative blood purification therapy in patients with maintenance hemodialysis therapy who underwent living donor liver transplantation.

Living donor liver transplantation (LDLT) is a treatment for end-stage liver failure, and was developed to overcome the distinct insufficiency of cadaveric donors. Case 1 is a 56-year-old man who had undergone maintenance hemodialysis therapy for 4 years. An LDLT was performed for the treatment of advanced liver cirrhosis and hepatocellular carcinoma. Continuous hemodiafiltration (CHDF) was performed from the 2nd to 5th days after the operation. Case 2 is a 55-year-old man with primary amyloidosis and chronic renal failure. An LDLT was performed for the treatment of severe abdominal distention caused by a large liver volume. Although CHDF was started at the 3rd day after the operation, it was discontinued within 24 hours because of an increased urinary volume. CHDF was required again from the 6th-8th days, after which the blood purification mode was switched to regular intermittent hemodialysis. Meanwhile, no major problems occurred in either case. In conclusion, CHDF was required for about 5 days from the 2nd day after the operation. The application of careful and aggressive blood purification therapy during the perioperative period is a key to successful LDLT in dialysis patients.

Hemodiafiltration↗

PubMed2003

Effect of nitrite and nitrate on biogenic sulfide production in sewer biofilms determined by the use of microelectrodes.

The effects of O2 and NO3- concentrations on in situ sulfate reduction and sulfide reoxidation in microaerophilic wastewater biofilms grown on rotating disk reactors were investigated by the use of microelectrodes for O2, S2-, NO3-, NO2-, and pH. Microelectrode measurements showed the vertical microzonation of O2 respiration, NO3- respiration, H2S oxidation and SO4(2-) reduction in the biofilms. The microelectrode measurements indicate that sulfate reducing activity was largely restricted to a narrow anaerobic zone located about 500 microm below the biofilm surface. An addition of nitrate forced the sulfate reduction zone deeper in the biofilm and reduced the specific sulfate reduction rate as well. The sulfate reduction zone was consequently separated from the O2 and NO3- respiration zones. Anaerobic H2S oxidation with NO3- was also induced by addition of nitrate to the medium. Measurements of the reduced inorganic sulfur compounds (FeS, FeS2 and S0), total-Mn and total-Fe in the biofilm indicated that the produced H2S became immediately oxidized with O2, NO3- and other oxidants, mainly ferric/ferrous hydrates. On the basis of the present results, it was estimated that of all sulfide produced, 13% of the sulfide was precipitated by metal ions as FeS and S0 just above the sulfate reduction zone, 65% was anaerobically oxidized to SO4(2-) with NO3- as an electron acceptor and 22% was aerobically oxidized within the biofilm incubated in 70 micromol l(-1) of DO and 280 micromol l(-1) of NO3-.

Biofilms↗

PubMed2003

[Off-pump coronary artery bypass grafting for severe acute coronary syndrome].

UNLABELLED: Off-pump coronary artery bypass grafting (off-pump CABG: OPCAB) has become a standard procedure, but the indication for the patients with severe acute coronary syndrome (ACS) has not been established. The purpose of this study is to evaluate the role of OPCAB for patients with acute myocardial infarction (AMI) and impending myocardial infarction (IMI). Clinical indication of OPCAB for acute coronary syndrome between November 1997 and December 2002, 14 patients diagnosed ACS out of 220 CABG cases underwent surgery. Twelve male and 2 female with a mean age of 66.3 +/- 7.5 were NYHA grade IV condition before surgery. Three of nine AMI cases and 4 of 5 IMI cases underwent OPCAB. Thirteen cases needed intra-aortic balloon pumping (IABP) support pre-operation, in 1 AMI and 2 IMI cases IABP had to be weaned during operation. The mean graft number was 2.6. Except one AMI case with severe cardiac damage, 13 cases were discharged in NYHA grade I-II condition. CONCLUSION: In early onset cases with still rising CK-MB, operative risk and result is difficult to evaluate pre-operatively. Equal results could be seen in IMI cases with no previous myocardial damage. We suggest, that in cases without severe myocardial damage, OPCAB could be one alternative treatment.

Aged↗

PubMed2003

Combined minimally invasive procedure for descending thoracic aortic aneurysm with left main coronary artery disease.

A 78-year-old man had a descending thoracic aortic aneurysm with left main coronary artery disease. Combined beating heart coronary artery bypass and endovascular thoracic aortic aneurysm repair was performed without cardiopulmonary bypass. The left anterior descending artery and the obtuse marginal branch of the left circumflex artery were revascularized through a left antero-lateral small thoracotomy. The aneurysm was excluded with stent grafts through a small femoral incision. This combined less invasive procedure is a promising approach providing better surgical results in patients with thoracic aortic aneurysm and severe coronary artery disease.

Aged↗

PubMed2002

Analysis of the mouse transcriptome based on functional annotation of 60,770 full-length cDNAs.

Only a small proportion of the mouse genome is transcribed into mature messenger RNA transcripts. There is an international collaborative effort to identify all full-length mRNA transcripts from the mouse, and to ensure that each is represented in a physical collection of clones. Here we report the manual annotation of 60,770 full-length mouse complementary DNA sequences. These are clustered into 33,409 'transcriptional units', contributing 90.1% of a newly established mouse transcriptome database. Of these transcriptional units, 4,258 are new protein-coding and 11,665 are new non-coding messages, indicating that non-coding RNA is a major component of the transcriptome. 41% of all transcriptional units showed evidence of alternative splicing. In protein-coding transcripts, 79% of splice variations altered the protein product. Whole-transcriptome analyses resulted in the identification of 2,431 sense-antisense pairs. The present work, completely supported by physical clones, provides the most comprehensive survey of a mammalian transcriptome so far, and is a valuable resource for functional genomics.

Alternative Splicing↗

PubMed2002

Eclamptic encephalopathy: MRI, including diffusion-weighted images.

Eclampsia is a rare condition peculiar to pregnant and puerperal women. We analyse imaging features in five patients with eclampsia, and determine whether diffusion-weighted imaging (DWI) could differentiate cytotoxic and vasogenic oedema in four of them. All were imaged within 4 days of the onset of symptoms. We found lesions with a prolonged T2 in the brain of all five patients, in the basal ganglia in four, pons in three and posterior cerebral white matter in two. Isotropic DWI revealed variable intensity in these regions. The ADC was decreased in one, and increased in all the others. The lesion with reduced ADC progressed to infarction.

Adult↗

PubMed2002

Concomitant laparoscopic splenectomy and cholecystectomy as an effective and minimally invasive treatment of pyruvate kinase deficiency with gallstones.

A 4-year-old girl with pyruvate kinase deficiency underwent partial splenic embolization initially. However, even after this procedure, she still had to be transfused every 2 months and then every month. At 5 years of age, she was admitted to our hospital to undergo splenectomy. She underwent laparoscopic splenectomy and concomitant cholecystectomy for gallstones. The hemogram recovered to the normal range after surgery, and her postoperative course was uneventful. Considering the absence of morbidity, the short hospitalization, the quick return to normal activity, the good cosmetic result, and the improved clinical and hematologic results, we consider that simultaneous laparoscopic splenectomy and cholecystectomy is safe and effective for the management of hemolytic anemia resulting from pyruvatre kinase deficiency and associated with cholelithiasis.

Child, Preschool↗

PubMed2002

Long-term adaptation to prism-induced inversion of the retinal images.

For 1 week, healthy human participants ( n=7) were devoid of normal vision by exposure to prism lenses that optically rotated their perceived world around the line of sight by 180 degrees. Adaptation to such prisms involved sustained and vigorous practice of the ability to redirect the unadapted efferent motor command; because prior to all visually guided movements, the to-be-executed efferent command was based on incorrect (prismatically reversed) spatial information. The time course of this sort of adaptation was systematically explored in Cooper-Shepard mental rotation (MR) tests and in naturalistic motor-tasks for the purpose of investigating whether mental rotations of the direction of the intended movement share common aspects with the process of MR. A control group ( n=7) intermittently exposed to the distorted spatial organization of the central visual field was studied in parallel. The main results were as follows: (a) the MR reaction times (RTs) day 1 with prisms appeared to be very similar to the normal RTs (day 1, no-prisms) with the one exception that subjects now responded within a prism (rotated) frame of spatial reference rather than within the environmentally upright. The visuomotor performance became grossly irregular and dysmetric. (b) The majority of the visuomotor adaptation functions began to level off on the 3rd day. (c) The increases in natural motor proficiency were accompanied by a systematic and noticeable decrease in magnitude of the MR Y-intercept obtained from the linear regression line calculated between each subject's RT and the various stimulus angles. MR slopes were stable through days 1-7 for both the experimental and control group. An increased correlation between rotational stimulus angle and RT suggested that the MR function also became progressively more tightly coupled to the stimulus angles. (d) Postadaptation measures of performance indicated the occurrence of selective and minimal adaptation in the natural motor tasks only. It is suggested that these results reflect an improved attentional (strategic) ability to replace incorrect (error producing) control signals with correct (error reducing) control signals. As a result, perceptual-motor start-up processes directly related to spatial coding and to the planning, initiation and correction of the intended direction of motor-or-mental movement improved while the subprocess ("stage") concerned with transformations of such movements remained unchanged. Visuomotor adaptation to inverting prisms engages, and thereby stimulates, a cortical system also invoked in the preparatory process of MR.

Adaptation, Physiological↗

PubMed2002

The effect of ethanol on the simultaneous transport and metabolism of methyl p-hydroxybenzoate in excised skin of Yucatan micropig.

The effects of ethanol on the simultaneous transport and metabolism of methyl p-hydroxybenzoate (HBM) were investigated in the skin of Yucatan micropig in vitro. It was found that transesterification occurred in the permeation studies involving ethanol. This was confirmed by monitoring the flux of ethyl p-hydroxybenzoate (HBE) into the receptor phase, as well as by monitoring the fluxes of HBM and p-hydroxybenzoic acid (HBA). The apparent flux of total HBM was decreased. The solubility of HBM increased with ethanol concentration, thus, the activity of HBM in ethanol solution became low because we used 10 mM HBM solution for permeation studies. The enhancement factor (E) was calculated to correct the activity. E increased with increasing the flux of ethanol, thus, ethanol may function as an enhancer of HBM transport. The hydrolysis of HBM to HBA was inhibited, whereas transesterification of HBM to HBE was induced at all concentrations of ethanol used (10-40%). The formation of HBE occurred much more readily than that of HBA at all concentrations of ethanol used.

Animals↗