Biomedical subjects

Y Watanabe

Publications and source records attributed to Y Watanabe.

At least 55 records · Page 3Linked to original sources

PubMed2004

[Evaluation of spinal cord ischemia in endovascular stent graft repair and surgical operation of descending thoracic or thoracoabdominal aortic aneurysms].

Between October 1996 and June 2003, endovascular stent graft repair was performed in 87 patients with descending thoracic aortic aneurysms, graft replacement was performed in 24 patients with thoracoabdominal aortic aneurysms, and endovascular stent graft repair with concomitant surgical bypass of abdominal visceral arteries was performed in 3 patients with thoracoabdominal aortic aneurysms. The retrievable stent graft was inserted and evoked spinal cord potential were monitored in order to predict spinal cord ischemia for stent graft repair. There was no paraplegia or hospital death, although 3 patients had paraparesis in stent graft repair. Two of the 3 patients with paraparesis made a full neurologic recovery. There were no cases of paraplegia or paraparesis in surgical operations with thoracoabdominal aortic aneurysm. The concomitant surgical procedure was a good technique for patients in whom cardiopulmonary bypass could not be used. Our results of stent graft repair and surgical operation for descending thoracic or thoracoabdominal aortic aneurysms were acceptable. The retrievable stent graft was useful for prediction of spinal cord ischemia before endovascular stent graft repair of descending thoracic or thoracoabdominal aortic aneurysm.

Adult↗

PubMed2004

Effects of hydroxylamine on microbial community structure and function of autotrophic nitrifying biofilms determined by in situ hybridization and the use of microelectrodes.

Effects of hydroxylamine (NH2OH), an intermediate of NH4+ oxidation, on microbial community structure and function of two autotrophic nitrifying biofilms fed with and without NH2OH were analyzed by a 16S rRNA approach and the use of microelectrodes. In the NH2OH-added biofilm, partial oxidation of NH4+ to NO2- was observed, whereas complete oxidation of NH4+ to NO3- was achieved in the control biofilm. In situ hybridization results revealed that no nitrite-oxidizing bacteria (NOB) hybridized with any specific probes were detected in the NH2OH-added biofilm. Thus, the addition of low concentrations of NH2OH (250 microM) completely inhibited the growth of NOB. Phylogenetic analysis of 16S rDNA indicated that the ammonia-oxidizing bacteria (AOB) detected in both biofilms were closely related to Nitrosomonas europaea, and that the clone sequences from both biofilm libraries have more than 99% similarity to each other. However, in situ hybridization results revealed that the addition of NH2OH changed the form of growth pattern of the dominant Nitrosomonas spp. from dense clusters mode to single scattered cells mode. Microelectrode measurements revealed that the average NH4+ consumption rate calculated in the NH2OH-added biofilm was two times higher than that in the control biofilm. This clearly demonstrated that the oxidation of NH4+ was stimulated by NH2OH addition.

Biofilms↗

PubMed2004

Reduced low-density-lipoprotein cholesterol causing low serum cholesterol levels in gastrointestinal cancer: a case control study.

Several epidemiological studies suggested an inverse relation between serum cholesterol level and cancer mortality. We analyzed the relation between gastrointestinal cancers and serum cholesterol levels. A total of 631 patients were recruited as cancer-bearing cases, comprising 181 esophageal cancers, 251 gastric cancers and 199 colorectal cancers. A case-control analysis was conducted on the serum TC, HDL-C, LDL-C and TG levels. TC and LDL-C were significantly lower in cancer-bearers by approximately 15 mg/dl. Furthermore, analyses by cancer site also showed significantly lower TC and LDL-C levels in cancer-bearers than in controls for all three sites. In this analysis, early stage cancer-bearers showed a significant decrease in TC levels by approximately 11 mg/dl compared with controls, and also a similar decrease in LDL-C levels. These results suggest that low TC levels are not related to cancer stage. Furthermore, findings of no significant differences in HDL-C and TG between cancer-bearing cases and controls in addition to a specific decrease in LDL-C in cancer-bearers suggest that hypocholesterolemia observed in these cases stems from low LDL-C. However, cancer-bearers and controls showed a similar distribution of TC and LDL-C levels. We should be aware that latent cancer bearers may be present among subjects with hypocholesterolemia.

Case-Control Studies↗

PubMed2004

Effect of residual ozone on membrane fouling reduction in ozone resisting microfiltration (MF) membrane system.

The effect of residual ozone on reducing the membrane fouling was investigated using ozone resisting microfiltration membrane. It was found out that the fouling was reduced effectively by maintaining residual ozone in the membrane module. To clarify the reason why the residual ozone reduces the membrane fouling, research was focused on the molecular degradation reaction and particle destabilization reaction induced by residual ozone. The major reason of membrane fouling reduction was attributed to the reduction of reversible resistance induced by the cake layer. The reversible resistance was reduced due to degradation of organic substances in the cake layer. In addition to degradation reaction, the increase of fouling particle size due to residual ozone in the cake layer is another important process for fouling reduction. This effect has been referred to as ozone-induced destabilization reaction. The calcium present in the raw water influenced this reaction. The increase of fouling particles size improves the filterability through the cake layer and backwashing efficiency.

Biodegradation, Environmental↗

PubMed2004

Influence of suspension viscosity and colloidal particles on permeability of membrane used in membrane bioreactor (MBR).

In this study, pilot scale experiments were carried out to examine membrane fouling occurring in membrane bioreactors (MBR) with or without pre-treatment (coagulation/sedimentation). Especially, the influence of suspension viscosity and dissolved organic matter (DOM) on membrane fouling was investigated. The pre-coagulation/sedimentation process improved the performance of a MBR in terms of membrane permeability by controlling irreversible fouling and formation of thick cake layer. The upper limit of MLSS concentration for an efficient operation in MBR without pre-treatment was suggested to be around 10 g/L based on the measurement of suspension viscosity. In this study, it was difficult to directly relate membrane fouling to DOM detected in the membrane chamber. A series of laboratory scale dead-end filtration experiments was carried out to investigate which fractions in biomass suspension would be the most influential in the deterioration of membrane permeability. Based on the dead-end tests, it was shown that the deterioration of membrane permeability was mainly caused by the colloidal particle fraction in the biomass suspension.

Biomass↗

PubMed2004

Behavior of micro-particles in monolith ceramic membrane filtration with pre-coagulation.

This paper is intended to clarify the characteristics unique to monolith ceramic membranes with pre-coagulation by referring to the behavior of micro-particles. Flow analysis and experiments have proved that monolith ceramic membranes show a unique flow pattern in the channels within the element, causing extremely rapid flocculation in the channel during dead-end filtration. It was assumed that charge-neutralized micro-particles concentrated near the membrane surface grow in size due to flocculation, and as a result, coarse micro-particles were taken up by the shearing force to flow out. As the dead end points of flow in all the channels are located near the end of the channels with higher filterability, most of the flocculated coarse particles are formed to a columnar cake intensively at the dead end point. Therefore cake layer forming on the membrane other than around the dead end point is alleviated. This behavior of particle flocculation and cake formation at the dead end point within the channels are unique characteristics of monolith ceramic membranes. This is why all monolith ceramic membrane water purification systems operating in Japan do not have pretreatment equipment for flocculation and sedimentation.

Ceramics↗

PubMed2003

Electronic structure of a polydiacetylene nanowire fabricated on highly ordered pyrolytic graphite.

A molecular wire candidate, the polydiacetylene chain, fabricated in a substantial support layer of monomers self-assembled on a highly ordered pyrolytic graphite surface, was studied using scanning tunneling microscopy and spectroscopy. The density of states of individual polymers and constituent monomers were observed on the same surface, and then compared with the calculated results. The spectrum delineating the density of states of the polydiacetylene wire clearly reveals the theoretically predicted pi-band and band edge singularities of the one-dimensional polymer.

Journal Article↗

PubMed2003

The effects of pitch tilt on postrotatory nystagmus in cats.

When the head is tilted away from the upright position immediately after termination of earth-vertical axis (EVA) head rotation at a constant velocity, the rotation axis of postrotatory nystagmus (PRN) is gradually directed toward gravity (spatial reorientation). During roll tilt, the extent of the axis shift varies among species. In cats, the reorientation is limited to about 30-45 degrees of head tilt. In the present study, we examined features of PRN during pitch tilt in cats. The animals were rotated about EVA at a constant velocity of 100 degrees /s for 120 s. Within 2 s after stopping EVA rotation, the animals were tilted toward the pitch plane by as much as +/-90 degrees (nose-down or nose-up) in steps of 15 degrees. Eye movements were measured with 3D magnetic search coils. The angle of the PRN plane and its slow phase eye velocity (SPV) were measured. The duration of PRN decreased as pitch tilt increased regardless of whether the direction was nose-up or nose-down. The mean time constant of SPV was significantly longer for nose-up than for nose-down. PRN maintained its horizontal orientation without any vertical drift during pitch tilt, but there was little reorientation toward gravity. That is, no significant torsional component of SPV emerged to reorient the eyes according to gravity. Our results indicate that spatial reorientation depends on head orientation. For the PRN responses after pitch tilts in cats, the interactions of semicircular canal and otolith inputs in the central vestibular system might be vestigial.

Animals↗

PubMed2003

Phase I/II study of docetaxel and cisplatin with concurrent thoracic radiation therapy for locally advanced non-small-cell lung cancer.

Recent studies have suggested the superiority of concomitant over sequential administration of chemotherapy and radiotherapy. Docetaxel and cisplatin have demonstrated efficacy in advanced non-small-cell lung cancer (NSCLC). This study evaluated the safety, toxicity, and antitumour activity of docetaxel/cisplatin with concurrent thoracic radiotherapy for patients with locally advanced NSCLC. Patients with locally advanced NSCLC (stage IIIA or IIIB), good performance status, age or=3 toxicities of 71, 60, 24, and 19%, respectively. Toxicity was significant, but manageable according to the dose and schedule modifications. Dose intensities of docetaxel and cisplatin were 86 and 87%, respectively. Radiotherapy was completed without a delay in 67% of 42 patients. The overall response rate was 79% (95% confidence interval (CI), 66-91%). The median survival time was 23.4+ months with an overall survival rate of 76% at 1 year and 54% at 2 years. In conclusion, chemotherapy with cisplatin plus docetaxel given on days 1, 8, 29, and 36 and concurrent thoracic radiotherapy is efficacious and tolerated in patients with locally advanced NSCLC and should be evaluated in a phase III study.

Adult↗

PubMed2003

Antioxidant property of metallothionein in fasted mice.

Metallothionein (MT) is a low-molecular-weight and sulfur-rich protein that is induced by not only heavy metals but also physiological stresses such as fasting and restraint stresses. Although MT plays a role as a radical scavenger and a regulator of metabolism of metals, the biological function of MT induced by fasting stress has not been elucidated. In this study, we investigated the antioxidative role of MT in fasted mice. In fasted mice, the lipid peroxidation level of the liver was elevated by 24-h fasting stress, and pre-induction of hepatic MT by Zn diminished hepatic lipid peroxidation. Although 24-h fasting stress induced MT synthesis in the liver, other antioxidants such as catalase, manganese-superoxide dismutase (Mn-SOD), and glutathione peroxidase (GSHPx) were not activated in the liver. Moreover, the hepatic MT level was still elevated by fasting stress after seven cycles of repetition of alternate fasting and feeding every 24 h, but the activities of catalase, Mn-SOD and GSHPx were unchanged. These results indicate that MT induced by fasting stress plays partly as an antioxidant.

Animals↗

PubMed2003

Property of metallothionein as a Zn pool differs depending on the induced condition of metallothionein.

Metallothionein (MT) is a low-molecular-weight, cysteine-rich, heavy metal-binding protein with several putative physiological functions as a radical scavenger and a regulator of metabolism of Zn. Although the induction of hepatic MT by a wide range of stressors is a well-known phenomenon, little is known about the role of MT in stressful situations. Since MT regulates Zn metabolism, we investigated the differences between affinities of MT for Zn in various stressful conditions in this study. Divalent cadmium ions are capable of displacement of Zn from MT in vitro. Therefore, we assayed the binding of Zn to MT induced by various stimuli using in vivo administration of Cd. MT was induced by paraquat (PQ), a reactive oxygen generator, fasting stress and restraint stress. Apo-MT induced by them bound to Zn in vivo. Zn, which bound to MT induced by PQ, was displaced by the administration of Cd. However, Zn that had bound to MT induced by fasting stress and restraint stress was not displaced by Cd. Moreover, we assessed the in vivo affinity of Zn to MT induced by fasting stress under the condition of subchronic Cd exposure. Cd was administered to mice by subcutaneously implanted Alzet osmotic minipumps, which released constant amounts of Cd over a 14-day period. After 4 days, mice were fasted for 24 h and hepatic MT was examined. Interestingly, it was found that Zn had displaced Cd bound to MT. These findings indicate that the affinity of MT for Zn differs depending on the stimulus by which MT was induced. This is the first report on differences in the properties of MT depending on the stimulus used to induce MT.

Animals↗

PubMed2003

Hemodynamic response of ovarian artery after hCG injection.

We have analyzed ovarian hemodynamics immediately after human chorionic gonadotropin (hCG) administration in patients treated by clomiphene-hCG and human menopausal gonadotropin-hCG. This study involved 40 infertile women who signed consents to participate in this study. After intramuscular injection of 10000 IU hCG, the change of ovarian arterial blood flow (BF) was evaluated by color Doppler. Pulsatility index, resistance index, maximum velocity (V(max)), mean velocity, minimum velocity, cross-sectional area of ovarian artery (Area) and BF were measured before and 15-180 min after hCG administration. In the 36 subjects in which ovulation was induced successfully, V(max) and BF increased significantly even at 15 min after hCG administration and thereafter. In the 4 non-ovulatory subjects, no significant changes in any of indices at any of measured time points were observed. Comparative study of non-ovulatory and ovulatory subjects suggested that ovulation may be predicted by the ovarian hemodynamic analysis immediately after hCG administration.

Adult↗

PubMed2003

L523S, an RNA-binding protein as a potential therapeutic target for lung cancer.

Approaches to vaccine-based immunotherapy of human cancer may ultimately require targets that are both tumour-specific and immunogenic. In order to generate specific antitumour immune responses to lung cancer, we have sought lung cancer-specific proteins that can be targeted for adjuvant vaccine therapy. By using a combination of cDNA subtraction and microarray analysis, we previously reported the identification of an RNA-binding protein within the KOC family, L523S, to be overexpressed in squamous cell cancers of the lung. We show here that L523S exhibits significant potential for vaccine immunotherapy of lung cancer. As an oncofetal protein, L523S is normally expressed in early embryonic tissues, yet it is re-expressed in a high percentage of nonsmall cell lung carcinoma. The specificity of L523S expression in lung cancer was demonstrated by both mRNA and protein measurements using real-time PCR, Western blot, and immunohistochemistry analyses. Furthermore, we show that immunological tolerance of L523S is naturally broken in lung cancer patients, as evidenced by detectable antibody responses to recombinant L523S protein in eight of 17 lung pleural effusions from lung cancer patients. Collectively, our studies suggest that L523S may be an important marker of malignant progression in human lung cancer, and further suggest that treatment approaches based on L523S as an immunogenic target are worthy of pursuit.

Biomarkers, Tumor↗

PubMed2003

Inhibitory effects of D2 agonists by striatal injection on excessive release of dopamine and hyperactivity induced by Bay K 8644 in rats.

We investigated by means of behavioral and neurochemical studies the effects of either D(1) or D(2) agonist on excessive dopamine release and hyperactivity induced by the microinjection of Bay K 8644, and an L-type Ca(2+) channel stimulant, into the rat caudate putamen under a novel environmental condition. Hyperactivity (locomotor activity and rearing counts) and significant increases in extracellular dopamine levels induced by Bay K 8644 were concomitantly observed. D(1) agonist, SKF81297, administered into the caudate putamen did not block Bay K 8644-induced hyperactivity measured by monitoring both animal activity and increases in extracellular dopamine levels detected by microdialysis. Pretreatment with the D(2) agonists, bromocriptine, talipexole and pramipexole, into the caudate putamen significantly blocked Bay K 8644-induced hyperactivity for 45 min after Bay K 8644 administration, although the single administration of these agonists significantly potentiated locomotor activity and rearing behavior. Furthermore, these agonists significantly suppressed Bay K 8644-induced extracellular dopamine levels. Our results indicate that these D(2) agonists (1) act on postsynaptic neuronal D(2) receptors under conditions of normal or low dopamine release in the caudate putamen, and (2) act on presynaptic D(2) receptors (autoreceptors) when excessive levels of dopamine are released or hyperdopamine neuronal activity is induced. Consequently, the effect of D(2) agonists in the clinical treatment of Parkinson's disease may be due to stimulation of postsynaptic D(2) receptors rather than presynaptic autoreceptors.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed2003

Differential activation in the medial temporal lobe during a sound-sequence discrimination task across age in human subjects.

To elucidate the brain mechanisms to encode sequential events, event-related potentials (ERPs) were recorded during a sound-sequence discrimination task using young and middle-aged adult subjects. In the task, a series of six or 12 kinds of natural sounds were sequentially presented; 70-80% of the stimuli were presented in a fixed order (Non-target), but the remaining stimuli, in a random order (Target). The subjects were instructed to detect the Targets and press a button at the end of each Target. In a control task, the same sounds were randomly presented (Control), and they were instructed to press the button at the end of each sound. Behavioral results indicated that the young subjects learned the task faster than did the middle-aged subjects. Positive ERP waves were evoked by Targets and Non-targets in the parieto-occipital area around 300-700 ms after stimulus onset. The mean amplitudes during this period in the young subjects were larger in Target than Control conditions, and those in Target condition were larger in the young than middle-aged subjects. Furthermore, the mean amplitudes in the Target condition were significantly correlated with behavioral performance. Equivalent dipoles for the ERPs evoked by Targets were estimated in the medial temporal lobe including the hippocampal formation and parahippocampal gyrus. The results suggest that the ERPs around 300-700 ms latency are involved in sound-sequence information processing. Furthermore, decrease in amplitudes of this positivity in the middle-aged subjects suggests that age-related memory decline is associated with deficits in encoding and retrieval of unfamiliar sequence.

Acoustic Stimulation↗

PubMed2003

Pharmacokinetics of a novel anti-asthmatic, scoparone, in the rabbit serum assessed by a simple HPLC method.

The pharmacokinetics of scoparone (Sco), an anti-asthmatic coumarin derivative extracted from the traditional Chinese herb "Yin Chen", was determined in rabbit plasma by a high performance liquid chromatography (HPLC) method which was newly developed using a Nova-Pak Silica C(18) column and a mobile phase of acetonitrile-water (20:80, v/v). After intravenous administration of Sco at a dose of 2.0 or 3.6 mg/kg, the time course of the plasma concentration of Sco was found to fit an open two-compartment model. AUC values increased, dose-dependently. Mean T(1/2) values showed that half-life was dosage independent. Distribution and elimination of Sco in rabbit plasma were both relatively rapid. These results indicate that Sco could be easily administrated by spray inhalers and is expected to have few associated side effects.

Animals↗

PubMed2003

Tuberculous abdominal aortic pseudoaneurysm penetrating the left psoas muscle after BCG therapy for bladder cancer.

We describe a case of a 75-year-old man with abdominal aortic and right femoral tuberculous pseudoaneurysms 32 months after intravesical bacillus Calmette-Guerin therapy for bladder cancer. These aneurysms were probably brought on by systemic infection by Mycobacterium bovis. The infrarenal aorta and right common femoral artery were successfully replaced with an in situ expanded polytetrafluoroethylene graft. Tuberculous pseudoaneurysm after bacillus Calmette-Guerin therapy for malignancy is very rare, and we review the related literature.

Aged↗

PubMed2003

Levofloxacin based triple therapy as a second-line treatment after failure of helicobacter pylori eradication with standard triple therapy.

BACKGROUND: Successful eradication of Helicobacter pylori infection after failure of standard triple therapy is difficult. The efficacy and safety of levofloxacin based triple therapy as a first-line therapy has-been studied. AIMS: The aim was to evaluate the efficacy and tolerability of levofloxacin based therapy after a failed standard triple therapy. PATIENTS: We conducted a prospective, uncontrolled study of a consecutive series of 33 patients who failed eradication with 1 week of lansoprazole-amoxicillin-clarithromycin triple therapy. METHODS: The subjects were retreated with 1 week of LA-LVFX triple therapy (lansoprazole, 30 mg twice daily; amoxicillin, 1000 mg twice daily: levofloxacin, 200 mg twice daily). Cure of infection was defined as negative results from culture, histology and a urea breath test 4 to 8 weeks after the second-line therapy. RESULTS: The eradication rate was 69.7% (23/33) by both intention-to-treat and per-protocol analyses (95% confidence interval=61-79%). Seven (21.2%) patients experienced mild side-effects, such as soft stools and taste disturbance. No patient stopped the medication on account of adverse effects. CONCLUSIONS: Levofloxacin based triple therapy is an effective second-line treatment after a failed standard triple therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗