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Biomedical subjects

H Yamada

Publications and source records attributed to H Yamada.

At least 37 records · Page 2Linked to original sources
PubMed2006

Control of bromate ion and brominated organic compounds formation during ozone/hydrogen peroxide treatment of secondary effluent.

Ozonation and ozone process combined with hydrogen peroxide have been identified as new technologies for direct or indirect reuse of wastewater. This study aims to establish appropriate conditions to control the formation of BrO3 and brominated organic compounds during O3/H2O2 treatment of secondary effluents of sewage. When the H2O2/O3 mole ratio of injection was above 0.5 and the DO3 concentration was below 0.1 mg/L, BrO3 was controlled as well as treatment purpose was completed. TOBr formation in O3/H2O2 treatment was also completely controlled.

Bromides↗
PubMed2006

Presence of prostacyclin receptor in arteriosclerotic human femoral artery.

AIM: Prostacyclin, which is mainly synthesized by vascular endothelial cells, exerts antiplatelet and smooth-muscle-relaxant effects, thereby maintaining cardiovascular homeostasis. Prostacyclin analogues have been clinically proven to improve ischemic symptoms and prevent the occurrence of vascular events in the lower extremities of patients with arteriosclerosis obliterans. We examined the presence of prostacyclin receptor (IP receptor) in an arteriosclerotic human femoral artery. METHODS: Specimens of the femoral artery were obtained at the time of limb amputation from an 83-year-old woman. Atherosclerotic lesions and associated changes such as calcification were evident. The specimens were stained with hematoxylin and eosin, and processed for immunohistochemistry. RESULTS: A monolayer of cells was observed on the luminal side of the femoral artery. Single immunohistochemistry showed the presence of the IP receptors on cells of the luminal side of the femoral artery. Triple-immunofluorescence staining revealed colocalization of IP-receptor-positive cells and cells positive for von Willebrand factor, a marker of vascular endothelial cells. CONCLUSIONS: We investigated the presence of the IP receptor in the human femoral artery immunohistochemically, and demonstrated their strong expression in endothelial cells. This finding suggests that prostacyclin or prostacyclin analogues may act on their receptors on endothelial cells in patients with arteriosclerosis obliterans.

Aged, 80 and over↗
PubMed2006

Preparation of mycobacteria-containing artificial sputum for TB panel testing and microscopy of sputum smears.

SETTING: Panel testing, blinded cross rechecking and on-site evaluation are the three methods for external quality assessment (EQA) of acid-fast bacilli (AFB) smear microscopy. Panel testing can provide data on laboratory capabilities prior to implementing a rechecking programme, assess the current status of laboratory performance and detect problems associated with diagnostic performance. Thus far, two methods for preparing panel test slides have been reported: these use real AFB-positive and -negative sputum treated with sodium hydroxide (NaOH) or N-acetyl-L-cysteine (NALC). OBJECTIVE: To evaluate the above methods and to develop a new method to prepare panel test slides with artificial sputum. DESIGN: Panel test slides were prepared using the NaOH and NALC methods. New artificial sputum preparation methods were developed and examined using a cultured monocyte cell line, cultured avirulent mycobacteria and methylcellulose or polyacrylamide gel as substrate. Smears prepared by the four methods were compared. RESULTS: Panel test slides prepared with NaOH and NALC methods are not macroscopically or microscopically similar to real smears. Our new artificial sputum is similar to real sputum in viscosity and macroscopic and microscopic appearance; it is also consistent in panel positivity grades. CONCLUSION: The artificial sputum described here could contribute to the EQA and training in tuberculosis laboratories or microscopy centres.

Acetylcysteine↗
PubMed2005

Facial emphysema caused by cheek bite.

Biting of the buccal mucosa is very frequent injury, whereas facial emphysema caused by cheek bite is rare. We report a case of facial emphysema causing puffing of the cheek through a self-inflicted bite of the buccal mucosa.

Bites, Human↗
PubMed2005

High-speed gas sensor for chemosensory event-related potentials or magnetic fields.

The observation of odor and air exchange with high temporal accuracy is necessary to obtain strict chemosensory event-related potentials (CSERPs) or magnetic fields, as proposed by Evans et al. [Evans W, Kobal G, Lorig T, Prah J. Suggestions for collection and reporting of chemosensory (olfactory) event-related potentials. Chem Senses, 1993; 18: 751- 6]. No suitable method for real time observation of gas stimuli, however, has been available until now. We have developed a technique to measure accurately gas molecule concentrations with a high temporal resolution. We determined that attenuation of sound amplitude varies in a manner dependent on the average molecular weight through which the sound wave passes. Based on this principle, we have designed a high-speed gas concentration sensor utilizing ultrasound. We investigated the practical potential of this sensor using a chemosensory stimulator (olfactometer); we succeeded in observing rapid gas exchange between air and nitrogen with a 2 kHz sampling rate. The signal/noise ratio of the stimulus was greater than 42 dB. In a 20 min experiment we determined that, for this olfactometer, the gas onset latency was 79 ms and the rise time was 16 ms. No significant artifact to magnetic fields was observed, even when the sensor was situated near a whole head magnetoencephalography (MEG) system. These results indicate that this sensor could be used for the observation of odor and air exchange, as well as, for real time monitoring of odor stimuli during actual experiments with a participant.

Algorithms↗
PubMed2005

Reduced amplitude of the sural nerve sensory action potential in PARK2 patients.

The authors performed nerve conduction studies in nine PARK2 and eight idiopathic Parkinson disease patients and found a significant reduction of sural sensory nerve action potential (SNAP) amplitude in eight PARK2 patients who mostly remained asymptomatic. These data suggest that sensory axonal neuropathy may be a common clinical feature of PARK2 and a reduced amplitude of sural SNAP could be a diagnostic indicator of PARK2.

Action Potentials↗
PubMed2005

Retinal neovascularisation without ischaemia in the spontaneously diabetic Torii rat.

AIMS/HYPOTHESIS: The spontaneously diabetic Torii (SDT) rat has recently been established as a model of type 2 human diabetes mellitus. Male SDT rats develop severe diabetic ocular complications. This study investigated the nature of the ocular complications in this model and addressed the question of whether the SDT rat is a good model of human proliferative diabetic retinopathy. METHODS: Male SDT rats aged 50 weeks were studied for a period of 8 months. Under deep anaesthesia, one eye of each animal was enucleated following perfusion with fluorescein dextran and a retinal flat mount was prepared to study vascular structure. The other eye was enucleated and investigated histologically by haematoxylin-eosin and azan staining and by immunohistochemistry using antibodies against vascular endothelium (Griffonia simplicifolia isolectin B4 antibody) and vascular endothelial growth factor (VEGF). RESULTS: From the vascular structure study, 17 of 32 rats (53%) showed proliferative retinopathy without vascular non-perfusion. The histological study revealed traction retinal folds in rats with proliferative retinopathy. Azan staining showed some proliferative matrix in rats with normal retinal structure and those with proliferative retinopathy compared with normoglycaemic controls. Staining with Griffonia simplicifolia isolectin B4 antibody showed no specific vascular changes in any of the rats, while VEGF staining revealed higher immunoreactivity in the retina of rats with normal retinal structure and those with proliferative retinopathy, but only low immunoreactivity in the control animals. CONCLUSIONS/INTERPRETATION: There appear to be differences between the SDT rat model of diabetic retinopathy and human proliferative diabetic retinopathy, as the SDT rat develops retinal neovascularisation without retinal ischaemia. This very unique display of ocular neovascularisation may be caused by increased expression of VEGF.

Animals↗
PubMed2005

Conduction electron spin resonance of small silver particles.

Electron spin resonance (ESR) spectroscopy has been used to study the conduction electron spin resonance (CESR) of small silver particles stabilized in dehydrated Ag-rho zeolite. Silver particles were produced by hydrogen reduction at elevated temperatures and diameter of the stabilized particles was calculated based on the linewidth of CESR signal using Kawabata theory.

Electron Spin Resonance Spectroscopy↗
PubMed2005

Structure formation in a binary monolayer of dipolar particles.

We propose an experimental technique for an easy to control realization of a binary dipolar monolayer where the two components have oppositely oriented dipole moments constrained perpendicular to the plane of motion without the application of an external field. The experimental setup ensures that hydrodynamic effects do not play a crucial role in the structure formation, the particles move deterministically due to the dipole-dipole interaction. At low concentrations, cluster-cluster aggregation occurs with chainlike morphologies, while at high concentration the particles self-assemble into various types of binary crystal lattices, in good agreement with the theoretical predictions. The structures formed by the particles are found to be sensitive to external perturbations due to the central interparticle forces, however, static friction arising at the contact surface of particles can increase the stability compared to systems with only viscous friction.

Journal Article↗
PubMed2005

Localization properties of electronic states in a polaron model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers.

We numerically investigate localization properties of electronic states in a static model of poly(dG)-poly(dC) and poly(dA)-poly(dT) DNA polymers with realistic parameters obtained by quantum-chemical calculation. The randomness in the on-site energies caused by the electron-phonon coupling is completely correlated to the off-diagonal parts. In the single electron model, the effect of the hydrogen-bond stretchings, the twist angles between the base pairs and the finite system size effects on the energy dependence of the localization length and on the Lyapunov exponent are given. The localization length is reduced by the influence of the fluctuations in the hydrogen bond stretchings. It is also shown that the helical twist angle affects the localization length in the poly(dG)-poly(dC) DNA polymer more strongly than in the poly(dA)-poly(dT) one. Furthermore, we show resonance structures in the energy dependence of the localization length when the system size is relatively small.

Biophysical Phenomena↗
PubMed2005

Pigment epithelium-derived factor induces pro-survival genes through cyclic AMP-responsive element binding protein and nuclear factor kappa B activation in rat cultured cerebellar granule cells: Implication for its neuroprotective effect.

Pigment epithelium-derived factor (PEDF) protects immature cerebellar granule cell neurons (CGCs) against apoptosis induced by K+ and serum deprivation. However, the precise mechanism of this protection remains unknown. We recently reported that the transcription factor nuclear factor kappa B (NF-kappaB) is activated in PEDF-treated CGCs. Although it is well known that NF-kappaB blocks apoptotic cell death through the induction of pro-survival factors, the effects of PEDF on the expression of these factors are not fully understood. In this study, we employed the use of reverse transcriptase-polymerase chain reaction to analyze the gene expression of certain pro-survival genes and found that genes such as c-IAP1, c-IAP2, FLIPs, A1/Bfl-1 and Mn-SOD were induced in PEDF-treated neurons. On the other hand, no induction was observed of the pro-apoptotic Bcl-2 family members Bax and Bid at any time from 3 to 24 h following PEDF addition. Furthermore, phosphorylation of cyclic AMP-responsive element binding protein (CREB) and increment of nuclear cyclic AMP-response element (CRE)-like DNA binding were observed in PEDF-treated CGCs. The anti-apoptotic effect of PEDF was blocked by overexpression of dominant negative CREB or a mutated form of IkappaBalpha. These results suggested that induction of both CRE- and NF-kappaB-dependent genes is required for the observed neuroprotective effects of PEDF on CGCs.

Animals↗
PubMed2005

Distribution of new methylene blue injected into the caudal epidural space in cattle.

To investigate the distribution of solutions injected into the first intercoccygeal epidural space, 24 adult, standing cattle were randomly assigned to 5-, 10- and 20-mL groups and injected with 0.12% new methylene blue (NMB) in 0.9% saline. Ten heifers received 1 mL NMB solution/100 kg of body weight. There was a significant correlation between the injected volume and the number of cranially stained spinal segments in three adult cattle groups (correlation coefficient R2=0.46; P<0.0001). In three cattle, NMB solution did not distribute more than one spinal segment cranially from the injection site due either to fibrosis of the epidural tissue or to inadvertent intravenous administration into the epidural vein. The study showed that the larger the volume of solution injected, the greater the spread with increased individual variation. The results could form the basis for determining the volume of injection required and for evaluating the pharmacokinetics of anaesthetics used in caudal epidural anaesthesia.

Anesthesia, Epidural↗
PubMed2005

A comparative study of the efficacy and safety profiles between fluvoxamine and nortriptyline in Japanese patients with major depression.

OBJECTIVE: The aim of this study was to compare the efficacy and safety profiles between fluvoxamine and nortriptyline in Japanese patients with major depression. METHODS: The efficacy and safety profiles of fluvoxamine, a selective serotonin-reuptake inhibitor, and nortriptyline were compared under a single-blind fashion in 74 Japanese patients with major depression. The efficacy was assessed using the 17-item Hamilton Rating Scale for Depression (HAM-D), Clinical Global Impression Scale (CGI) severity and improvement scores, while the safety profiles were assessed using the UKU Side Effect Rating Scale at baseline, and on days 7, 14, 28 and 56. Moreover, with the aim of determining the distinct efficacy profiles of each drug, the effects on each of the factor scores extracted by the principal component analysis performed for HAM-D scores were compared between drugs. RESULTS: Both drug groups showed significant amelioration of depressive symptomatology over the trial period lasting for 8 weeks. Statistical analyses revealed no significant between-group differences regarding the efficacy assessed by either HAM-D or CGI scores; however, the efficacy of nortriptyline tended to appear earlier than that of fluvoxamine. Moreover, no significant differences were obtained for the factor scores, representing 'depressed mood', 'physical symptoms' or 'sleep disturbances', although 'sleep disturbances' appeared to improve earlier in the nortriptyline group than in the fluvoxamine group. As for the safety profiles, the nortriptyline group scored a significantly higher incidence of adverse events such as dysarthria or orthostatic dizziness, as well as increased heart rate. CONCLUSIONS: These findings suggest that fluvoxamine is generally comparable to nortriptyline in its efficacy and superior in its safety profile, in accordance with findings obtained in previous comparative clinical trials conducted in Caucasian populations.

Adult↗
PubMed2005

Novel protein kinase C-beta isoform selective inhibitor JTT-010 ameliorates both hyper- and hypoalgesia in streptozotocin- induced diabetic rats.

AIM: Activation of protein kinase C (PKC) is thought to play an important role in the pathogenesis of diabetic microvascular complications. PKC-beta is elevated in hyperglycaemic conditions, both in vivo and in vitro. In this study, pharmacological effects of a novel PKC-beta isoform selective inhibitor, JTT-010 ((2R)-3-(2-aminomethyl-2,3-dihydro-1H-3a-azacyclopenta(a)inden-8-yl)-4-phenylaminopyrrole-2,5-dione monomethanesulphonate), on diabetic neuropathy were examined. METHODS: PKC inhibitory activity of JTT-010 was evaluated with an enzyme assay. For the in vivo study, streptozotocin (STZ)-induced diabetic rats were treated with JTT-010 for 12 weeks and tail/sciatic nerve conduction velocity (NCV) evaluated. Hyper/hypoalgesia was evaluated using tail-flick and formalin tests. RESULTS: JTT-010 inhibited PKC-betaI and -betaII with IC50 values of 4.0 and 2.3 nm respectively. For other PKC isoforms, IC50 values were 54 nm or greater. In STZ-induced diabetic rats showing a reduction in tail/sciatic nerve conduction velocities, JTT-010 (0.3-3 mg/kg) ameliorated the reduction of these velocities. In a formalin test, STZ-induced diabetic rats had hyperalgesia in the first phase. JTT-010 reduced nociceptive response at doses of 0.1 mg/kg or higher. Furthermore, STZ-induced diabetic rats showed hypoalgesia in the second phase of the formalin test and tail-flick test. JTT-010 also ameliorates these symptoms at doses of 0.1 mg/kg or higher. CONCLUSIONS: These observations suggest that PKC-beta contributes not only to diabetic hyperalgesia, but also to hypoalgesia and also contributes to defects in NCV. PKC-beta inhibitor, JTT-010, may be beneficial in suppressing the development of diabetic nerve dysfunction, including hyperalgesia and hypoalgesia.

Animals↗
PubMed2005

Preliminary results of moisture checker for Mucus in diagnosing dry mouth.

OBJECTIVE: To evaluate the ability of Moisture Checker for Mucus (MCM), a device which measures the weight percent of water content in the oral mucosal epithelium, for the diagnosis of dry mouth. METHOD: Forty-three consecutive patients seen at the Dry Mouth Clinic of Tsurumi University were divided into two groups by the diagnostic criteria of hyposalivation defined by the stimulated salivary flow rate < or =10 ml per 10 min. The MCM values in the buccal, tongue and labial mucosa in each group were compared. RESULTS: The value of the normal salivation group was significantly higher when compared with that of the hyposalivation group both in the buccal and tongue mucosa, P = 0.01 and P = 0.046, respectively. CONCLUSION: Moisture Checker for Mucus has the potential to be a useful device in the screening of hyposalivation.

Adult↗
PubMed2004

Maternal genetic polymorphisms in CYP1A1, GSTM1 and GSTT1 and the risk of hypospadias.

Hypospadias is one of the most common congenital anomalies. Increased exposure to environmental factors (endocrine-disrupting chemicals and smoking) or maternal endogenous estrogen may cause hypospadias because male sexual differentiation is dependent on normal androgen homeostasis. Moreover, interactions between genetic factors and cigarette smoking and other chemicals have been suggested. It has been demonstrated that the CYP1A1 metabolizes not only environmental chemicals but also estrogens, and glutathione-S-transferases (GSTs) are detoxification enzymes that protect cells from toxicants by conjugation with glutathione. In this study, to investigate the association of CYP1A1 (MspI), GSTM1 and GSTT1 polymorphisms with hypospadias, a case-control study of 31 case mothers who had boys with hypospadias and 64 control mothers was performed in Japan. These polymorphisms were investigated by PCR-based methods using DNA from peripheral lymphocytes. We found that the heterozygous CYP1A1 and heterozygous and homozygous CYP1A1 were less frequent in the case mothers than in the control mothers [adjusted odds ratio (OR)=0.17, 95% confidence interval (CI)=0.04-0.74, OR = 0.28, 95% CI = 0.08-0.97, respectively]. We found no effect of maternal smoking on the hypospadias risks among the gene polymorphisms. The results suggest that mothers with the CYP1A1 MspI variant allele may have a decreased risk for hypospadias.

Adult↗
PubMed2004

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss.

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.

Abortion, Habitual↗