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S Tanaka

Publications and source records attributed to S Tanaka.

At least 163 records · Page 9Linked to original sources
PubMed2002

Measurement of lineal-energy distributions for neutrons of 8 keV to 65 MeV by using a tissue-equivalent proportional counter.

The lineal-energy spectra for monoenergetic and quasi-monoenergetic neutrons of 8 keV to 65 MeV were obtained using a tissue-equivalent proportional counter (TEPC). The frequency-mean lineal energy, the dose-average lineal energy and mean quality factor were estimated from the measured data. The neutron absorbed doses obtained with this TEPC were compared with the kerma coefticient for A-150 plastic defined by ICRP 26 and the mean quality factors were compared with the data of ICRP 74. respectively. These comparisons indicated good agreement between them.

Alpha Particles↗
PubMed2002

Combining phacoemulsification with vitrectomy for treatment of macular holes.

AIM: To describe the results of combined phacoemulsification, insertion of posterior chamber intraocular lens (PCIOL), and pars plana vitrectomy for patients with macular hole. METHODS: A case series of 89 consecutive patients with macular hole who underwent combined phacoemulsification, insertion of PCIOL, posterior capsulectomy, and pars plana vitrectomy. RESULTS: 80 of 89 patients (89%) had their holes closed with the combined surgery. Four of the nine patients who failed had their holes closed with one further procedure. Of the 89 patients operated on, 61 (65%) had vision of 20/40 or better. Three patients (3%) had Snellen acuity of less than 20/400 postoperatively. Three patients (3%) developed retinal detachments, one with proliferative vitreoretinopathy (PVR). Eight patients (9%) developed CMO. Three patients developed late reopening of their macular holes after remaining closed for 9 months or more. CONCLUSION: Combined phacoemulsification, insertion of PCIOL, and pars plana vitrectomy surgery can be used to treat macular holes. Combining cataract surgery with vitrectomy surgery may prevent a later second operation for post-vitrectomy cataract formation.

Aged↗
PubMed2002

An antibody to VacA of Helicobacter pylori in cerebrospinal fluid from patients with Guillain-Barre syndrome.

OBJECTIVE: To detect antibodies to recombinant vacuolating cytotoxin (r-VacA) of Helicobacter pylori in cerebrospinal fluid (CSF) from patients with Guillain-Barre syndrome (GBS). METHODS: CSF samples from 13 patients with GBS (electrophysiologically classified as eight acute inflammatory demyelinating polyradiculoneuropathy (AIDP), four acute motor axonal neuropathy (AMAN), and one unexcitable nerve conduction) and eight disease control patients were studied. The r-VacA protein was separated by SDS/PAGE, and Western blot analysis was carried out. RESULTS: Six of the 13 patients with GBS had a specific IgG antibody to VacA of H pylori, which was confirmed by absorption experiments using r-VacA. Every patient with positive CSF anti-r-VacA IgG had AIDP. CONCLUSION: The sequence homology previously found between VacA and human (Na(+)+K(+))-ATPase A subunit suggests that antibodies to VacA involve ion channels in abaxonal Schwann cell plasmalemma resulting in demyelination in some patients with GBS.

Adult↗
PubMed2002

Effect of serotonin (5-HT) on trigeminal rhythmic activities generated in in vitro brainstem block preparations.

We used rat isolated brainstem block preparations to analyze the functional roles of serotonin receptors in the generation of trigeminal rhythmic activities. We previously reported that trigeminal rhythmic activities could be induced by some pharmacological applications in an isolated brainstem preparation with a rostral boundary at the border between the inferior and superior colliculus, and a caudal border at the level of the rostral facial nucleus. However, the same stimulation did not induce trigeminal rhythmic activities in a whole brainstem block preparation with the same rostral boundary and a caudal border at the obex level. In the present study, both the 5-HT(1A) phthalimido-butyl-piperazine, and the 5-HT(2C) agonist, 1-2,5-dimethoxy-4-iodophenyl-2-aminopropane, combined with N-methyl-D,L-aspartate and bicuculline, elicited trigeminal rhythmic activities in a whole brainstem block preparation. Our results suggest that serotonin has both facilitation and inhibition effects on the generation of trigeminal rhythmic activities in an isolated brainstem block preparation in vitro.

Animals↗
PubMed2002

Expression profile of active genes in the human pituitary gland.

To characterize transcripts abundantly expressed in the human pituitary gland in general as well as to isolate novel transcripts expressed specifically in this gland, we generated an expression profile of the active genes transcribed in it. A total of 1015 randomly collected 3prime prime or minute expressed sequence tags (ESTs) (gene signatures, GSs) were grouped into 527GS species. The results showed the relative expression levels of genes in the pituitary gland. The genes comprising more than 1% of total mRNA were prolactin, growth hormone and chromogranin B genes. When known genes were categorized, the genes for pituitary hormones were the most actively transcribed, followed by the genes for ribosomal proteins, nuclear proteins and secretory granule proteins. Through comparison of this gene expression profile with the BodyMap database containing profiles generated from 63 other human tissues, we obtained 11 genes which appeared to be specifically expressed in the pituitary gland. In addition to the eight known genes, we identified three novel pituitary-specific transcripts which encode putative proteins: pituitary gland specific factor 1a (PGSF1a), PGSF1b and PGSF2. This expression profile method is a novel approach to the isolation of pituitary-specific genes that may have important functions.

Amino Acid Sequence↗
PubMed2002

Myocardial protection of the pressure overload hypertrophied heart in human cardiac surgery by acceleration of anaerobic glycolysis.

BACKGROUND: Because of the decreased tolerance to ischemia and increased reperfusion injury in hypertrophied myocardium, myocardial hypertrophy is a well known risk factor for cardiac surgery. We have previously demonstrated in a left ventricular hypertrophy (LVH) model that a highly buffered cardioplegic solution (HBS) that provided glucose as a substrate and promoted anaerobic glycolysis during ischemia afforded superior myocardial protection when compared to standard formulations. And we reported the superiority of this cardioplegia in human cardiac surgery. METHODS: In this study, 16 patients with aortic stenosis (AS) and LVH receiving HBS were reviewed and compared to another patient group with AS and LVH who received either cold blood cardioplegia (CBC; n=5) or glucose insulin potassium (GIK; n=6). RESULTS: Postoperative cardiac index was better in the HBS group than the other two groups with similar or lower catecholamine. CK-MB was lower in HBS group than GIK group, but this was not significant. Only one DC cardioversion was required in the HBS group, whereas 2 DC in the CBC group and total 7 DC in the GIK group. CONCLUSIONS: We found that histidine buffered cardioplegic solution provided comparable or better pump performance after surgery with relatively lower inotropic requirement, less DC cardioversion and homologous blood requirements for left ventricular hypertrophied heart associated with aortic stenosis.

Aged↗
PubMed2002

[Prosthetic valve endocarditis complicated with cardiogenic shock and disseminated intravascular coagulation; report of a case].

A 67-year-old man, who had been performed aortic and mitral valve replacement 3 years before, was admitted because of appetite loss, general fatigue and anemia. Although transthoracic echocadiogram showed no evidence of prosthetic valves failure, the patient fell in profound shock. He needed endotracheal intubation and inotropic support. Transesophageal echocadiogram revealed vegetation formation on the prosthetic mitral valve and massive periprosthetic valve leakage. The diagnosis of prosthetic valve endocarditis was established. Blood examination showed severe disseminated intravascular coagulation (DIC). The patient underwent re-mitral valve replacement and recovered well from shock and DIC.

Aged↗
PubMed2002

Prediction of improvement in regional left ventricular function after coronary artery bypass grafting: quantitative stress-redistribution 201Tl imaging in detection of myocardial viability.

BACKGROUND: This study investigated the usefulness of quantitative assessment of Thallium-201 stress redistribution myocardial scintigraphy combined with quantitative assessment of regional left ventricular function using the centerline method for predicting of recovery regional left ventricular function following myocardial revascularization. METHODS: Twenty patients with chronic total obstruction of the proximal portion of left anterior descending artery and/or right coronary artery were studied. Percent Tl-uptake method was used to evaluate myocardial viability before CABG. Regional LV function was evaluated before and after CABG with the centerline method. The territory of LAD was defined by chords 10 to 58 and that of RCA was defined by chords 59 to 80 in the centerline method. The parameter of regional left ventricular function was the mean (SF-Av.)/SD of each LAD and RCA territory. RESULTS: In cases showing a % uptake value under 50%, the preoperative value of (SF-Av.)/SD was -3.18+/-0.74 and postoperative value was -2.63+/-0.8 1. The difference between these values was not significant. When the %uptake value over 50%, the preoperative value of (SF-Av.)/SD was -2.80+/-0.49 and the postoperative value was -2.27+/-0.28. The postoperative value was significantly higher than the preoperative value(p=0.007). CONCLUSIONS: Even in cases of severe left ventricular dysfunction, regional left ventricular function improved if the value of % uptake in the redistribution Thallium imaging was 50% or over. Quantitative analysis of myocardial scintigraphy combined with quantitative analysis of left ventriculography is a useful method for predicting recovery of regional left ventricular function following myocardial revascularization.

Aged↗
PubMed2002

Removal of organics and nitrogen in sewage treatment using anoxic-aerobic recirculated filter.

The anoxic-aerobic recirculated filter (AARF) process was investigated on removal effciencies of organics and nitrogen with regard to loading rates, recirculation ratios of nitrified liquor and contribution of methane production and sulfate reduction in the treatment of the municipal sewage. The AARF process is composed of an anoxic filter for denitrification and an aerobic filter for nitrification and some of the nitrified liquor in the aerobic filter is recirculated to the anoxic filter. The AARF process successfully removed organics and nitrogen achieving high removal rates of 88% for COD and 64-74% for nitrogen. The recirculation ratio (Re) did not affect the COD removal efficiency but did affect the nitrogen removal, which was enhanced at a higher ratio (Re = 4). The methane production was not contributive to the COD removal but the COD consumed by the sulfate reduction was equivalent to 17% of total COD removed at Re = 2. We confirmed that the AARF process was applicable to the sewage treatment including nitrogen removal at a hydraulic retention time close to that of the conventional activated sludge process.

Bacteria, Aerobic↗
PubMed2002

Thermochemical pretreatment in the anaerobic digestion of waste activated sludge.

Effects of a thermochemical pretreatment on the anaerobic digestion of waste activated sludge (WAS) was investigated by semicontinuously-fed digesters operated at 37 degrees C. WAS from a return sludge line of a municipal sewage treatment plant was pretreated by autoclaving at 130 degrees C for 5 minutes after adding 0.3g NaOH/g VSS. Solids of WAS were thermochemically solubilized to one half and then 60% or more were in totality solubilized in anaerobic digesters fed with pretreated WAS at 2-8 days of hydraulic retention times (HRT), while only 16-36% were solubilized in digesters fed with raw WAS. The adverse effect of the set temperature (130 degrees C) on the biodegradability of protein was not found. As a result, removal rates of COD in digestion was increased from 38% to 57% at 8 days HRT by the pretreatment. A specific methane production rate in the pretreated process was three times as high as the normal process. The thermochemical pretreatment was found to be very effective to enhance biodegradability as well as solubilization of WAS in anaerobic digestion.

Bacteria, Anaerobic↗
PubMed2002

Long-term experimental study of the aquatic plant system for polluted river water.

Water purification using artificial wetlands and aquatic macrophyte is attracting attention as a purification technology that can create rich ecosystems while imposing a minimal load on the environment. Because an aquatic plant system requires a large surface area, design specifications and maintenance methods that can obtain the optimum purification effect per unit surface area must be established. Large experimental facilities have been constructed beside a polluted river flowing into Lake Kasumigaura and have been used for a three-year experiment using several kinds of aquatic plants. This report summarizes the characteristics and the design load of the aquatic plant system based on this study and results from other aquatic plant facilities.

Ecosystem↗
PubMed2001

Porcine enamel matrix derivative enhances trabecular bone regeneration during wound healing of injured rat femur.

To elucidate the effects of enamel matrix derivative (EMD: Emdogain) on bone regeneration in rat femurs after drill-hole injury, defects in bone were filled with either EMD or its carrier, PGA, as control. On postoperative days 4 to 28, dissected femurs were examined by means of various morphological approaches. In both experimental groups, formation of trabecular bone, which was immunostained for bone sialoproteins (BSP), had occurred in the medullary cavities at cylindrical bone defects on Day 7 postoperatively. Cuboidal osteoblasts were clearly observed on these newly-formed BSP-positive bone trabeculae. On Days 7 and 14, many multinucleated giant cells, which strongly expressed cathepsin K, had appeared on these bone trabeculae, indicating active bone remodeling. In these bone trabeculae, Ca and P weight % and Ca/P ratio were similar to those of cortical bone, and there was no significant difference between the PGA- and EMD-applied groups. Bone volume fraction of newly-formed bone trabeculae on Day 7 postoperatively was significantly higher in the EMD-applied group than in the PGA-applied controls. Because of active bone remodeling and the marked decrease of bone volume, on Days 14 and 28 postoperatively, however, there was no longer a significant difference in trabecular bone volume fraction between the experimental groups. Our results suggest that EMD possesses an osteo-promotive effect on bone and medullary regeneration during wound healing of injured long bones.

Animals↗
PubMed2001

Aberrations in the fragile histidine triad (FHIT) gene in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) seems to be closely associated with lung carcinogenesis. To identify the genetic characteristics of precancerous IPF lesions in the peripheral lung, we performed PCR-based microsatellite analysis with DNA extracted from microdissected tissues; fluorescent in situ hybridization (FISH) analysis of the fragile histidine triad (FHIT) gene and immunohistochemical analysis of Fhit protein expression in samples of metaplasias and bronchiolar epithelia obtained from patients with IPF. We used four microsatellite markers of the FHIT gene within or flanking the FHIT gene on chromosome 3p for loss of heterozygosity (LOH) analysis. LOH of the FHIT locus was frequently found among the lesions of metaplasias and bronchiolar epithelia in the patients with IPF [62 (52%) of 119 informative lesions]. Fifty-four (73%) of the 74 lesions of metaplasias and bronchiolar epithelia obtained from the IPF patients with lung carcinoma and 8 (17%) of the 46 samples obtained from the IPF patients without lung carcinoma showed LOH at the FHIT gene (P < 0.0001). We confirmed allelic loss in the metaplasias and bronchiolar epithelia of IPF by FISH analysis of the FHIT gene. Additionally, the level of Fhit protein expression in the metaplastic cells of IPF was frequently reduced. Our findings suggest that allelic loss of the FHIT gene may be involved in carcinogenesis in the peripheral lung of patients with IPF.

Acid Anhydride Hydrolases↗
PubMed2001

Prefrontal cortex, negative symptoms, and schizophrenia: an MRI study.

The present study measured prefrontal cortical gray and white matter volume in chronic, male schizophrenic subjects who were characterized by a higher proportion of mixed or negative symptoms than previous patients that we have evaluated. Seventeen chronic male schizophrenic subjects and 17 male control subjects were matched on age and handedness. Regions of interest (ROI) were measured using high-resolution magnetic resonance (MR) acquisitions consisting of contiguous 1.5-mm slices of the entire brain. No significant differences were found between schizophrenic and control subjects in mean values for prefrontal gray matter volume in either hemisphere. However, right prefrontal white matter was significantly reduced in the schizophrenic group. In addition, right prefrontal gray matter volume was significantly correlated with right hippocampal volume in the schizophrenic, but not in the control group. Furthermore, an analysis in which the current data were combined with those from a previous study showed that schizophrenic subjects with high negative symptom scores had significantly smaller bilateral white matter volumes than those with low negative symptom scores. White matter was significantly reduced in the right hemisphere in this group of schizophrenic subjects. Prefrontal volumes were also associated with negative symptom severity and with volumes of medial-temporal lobe regions - two results that were also found previously in schizophrenic subjects with mostly positive symptoms. These results underscore the importance of temporal-prefrontal pathways in the symptomatology of schizophrenia, and they suggest an association between prefrontal abnormalities and negative symptoms.

Adult↗
PubMed2001

Microsatellite instability is a genetic marker for the development of multiple gastric cancers.

Multiple gastric cancers are found in 5-15% of all patients with gastric cancer. However, no molecular markers have yet been shown to be clinically useful for predicting which patient will or will not have multiple gastric cancers. Recently, microsatellite instability (MSI) has been identified as a molecular marker for multiple colorectal cancers. To elucidate whether MSI could be used as a molecular marker for multiple gastric cancers, we examined MSI in 38 patients with a single gastric cancer, in 26 patients with synchronous multiple gastric cancers and in 14 patients with metachronous multiple gastric cancers. In the patients with synchronous multiple gastric cancers, 1 of the larger tumors was examined. In the patients with metachronous multiple gastric cancers, the first gastric cancer was examined. Five microsatellite loci, including D17S855, D18S58, D18S61, BAT25 and BAT40, were examined with microsatellite assay. MSI was divided into low frequency of MSI (MSI-L) and high frequency of MSI (MSI-H) by the number of affected loci. MSI-L was detected in 3 of the 38 (8%) patients with a single gastric cancer, in 7 of the 26 (27%) patients with synchronous multiple gastric cancers and in 6 of the 14 (43%) patients with metachronous multiple gastric cancers. MSI-H was detected only in 1 of the 38 (3%) patients with a single gastric cancer. The frequency of MSI-L was significantly higher in patients with multiple gastric cancers, both synchronous and metachronous, than in those with a single gastric cancer (p < 0.05 and p < 0.01, respectively). Patients with MSI(+) gastric cancer developed a significantly higher frequency of secondary gastric cancer, when compared with patients with MSI(-) gastric cancer (p < 0.05). These data suggest that MSI may play an important role in the development of multiple gastric cancers, and it may be used clinically as a molecular marker for the prediction of multiple gastric cancers.

Colorectal Neoplasms↗
PubMed2001

Activation of protein kinase C delays apoptosis of nerve growth factor-deprived rat sympathetic neurons through a Ca(2+)-influx dependent mechanism.

The effects of protein kinase C (PKC) activation on apoptosis depend on the cell type and on the isoenzymes activated. We show that the apoptosis of nerve growth factor (NGF)-deprived rat sympathetic neurons is delayed for about 24 h by treatment with O-tetradecanoylphorbol 13-acetate (TPA). The cell death was estimated by both morphological changes and the release of a cytoplasmic enzyme into the medium. The PKC inhibitor bisindolylmaleimide inhibited the TPA-mediated delay of neuronal death. The effect of TPA was abolished in conditions of Ca(2+)-free or in the presence of both Ca(2+)/calmodulin-dependent protein kinase II and phosphatidylinositol 3-kinase inhibitors, but was not blocked by either an L- or N-type Ca(2+) channel inhibitor. These results suggest that the survival of the NGF-deprived neurons may be supported by PKC activation followed by Ca(2+) influx.

Animals↗