Biomedical subjects

Satoshi Watanabe

Publications and source records attributed to Satoshi Watanabe.

18 recordsLinked to original sources

PubMed2003

Contribution of excitatory chloride conductance in the determination of the direction of traveling waves in an olfactory center.

Traveling waves have been found in the CNS of vertebrates and invertebrates. In the olfactory center [procerebrum (PC)] of the terrestrial slug Limax, periodic waves travel from the apex to the base with a frequency of approximately 0.7 Hz. The oscillation and propagation of waves have been thought to be mediated by the mutual connections of bursting neurons in the PC. The direction of the wave is Cl(-) dependent, because lowering the Cl(-) concentration in the medium reverses the direction. The bursting neurons have a Cl(-) channel-coupled glutamate receptor (GluClR), and, using a calcium imaging technique, the receptor was found to be excitatory. Activation of the GluClR with its selective agonist ibotenate resulted in an increased frequency of the oscillatory neural activity recorded as a periodic local field potential. Depletion of cytoplasmic Cl(-) with Cl(-)-free saline abolished all of the ibotenate-induced effects. Perforated-patch-clamp recording in single PC neurons revealed a spatial difference in the Cl(-)-dependent periodic depolarizations in the bursting neurons, with a higher amplitude in the apical region. These results suggest the involvement of excitatory GluClRs in the unidirectional propagation of waves in the PC.

Action Potentials↗

PubMed2003

Successful treatment of lymph node metastases recurring from gallbladder cancer.

A 66-year-old woman who had undergone cholecystectomy for the treatment of gallbladder cancer 5 years and 10 months previously was referred to our center due to increased carbohydrate antigen (CA)19-9. Increased CA19-9 (136U/ml) was the only abnormality detected on initial examination, and, despite various tests, clear signs of recurrence could not be detected. Subsequently, the patient was followed. Six months after the initial examination, dynamic computerized tomography confirmed lymphadenopathy. The results of fluoro-deoxy-glucose positron emission tomography suggested lymph node metastasis of the gallbladder cancer, and after consideration of the site of recurrence and the length of time between the primary surgery and detection of recurrence, the patient underwent extrahepatic bile duct resection and lymphadenectomy. Levels of CA19-9 normalized postoperatively, and, at the time of writing (26 months postoperatively), blood tests and diagnostic imaging revealed no signs of recurrence.

Adenocarcinoma↗

PubMed2003

Cloning and characterization of porcine common gamma chain gene.

The common gamma chain, which was originally identified as a component of interleukin-2 receptors (IL-2R), plays a key role in differentiation of T lymphocytes and natural killer (NK) cells. In the present study, cDNA of the porcine common gamma chain gene and its genomic DNA were molecularly cloned and characterized. The porcine common gamma chain gene was found to consist of 8 exons, spanning approximately 3.7 kb, and to encode a 368-amino acid polypeptide. The amino acid sequence showed 82.4%, 71.1%, 86.1%, and 84.8% similarities with that of human, murine, bovine, and canine chains, respectively. The common gamma chain gene was assigned to swine chromosome Xq13 by FISH analysis and was consistent with the result of radiation hybrid (RH) mapping. When various porcine tissues were examined for the expression of this gene, the expression was observed in lymphocytes and lymphocyte-related tissues. Since GATA, T cell factor-1 (TCF-1), Ets-1, activated protein2 (AP-2), and Ikaros2 binding motifs were demonstrated in the 5' upstream region of this gene, promoter activity was investigated using luciferase gene as a reporter. The results indicate that the Ets-1 binding motif in the segment from -95 to -59 (major transcription initiation site: +1) was an essential cis-acting regulatory element for the common gamma chain gene in lymphoid cells.

Amino Acid Motifs↗

PubMed2003

Quick and reversible inhibition of soybean root nodule growth by nitrate involves a decrease in sucrose supply to nodules.

The upper part of a nodulated soybean root hydroponically cultured in a glass bottle was monitored using a computer microscope under controlled environmental conditions, and the diameter of individual nodules was measured from 10-24 d after planting. The diameter of a root nodule attached to the primary root increased from 1 mm to 6 mm for 2 weeks under nitrogen-free conditions. The increase in diameter of the nodules was almost completely stopped after 1 d of supplying 5 mM nitrate, and was due to the cessation of nodule cell expansion. However, nodule growth quickly returned to the normal growth rate following withdrawal of nitrate from the solution. The reversible depression of nodule growth by nitrate was similar to the restriction of photoassimilate supply by continuous dark treatment for 2 d followed by normal light/dark conditions. In addition, the inhibitory effect of nitrate was partially alleviated by the addition of 3% (w/v) sucrose to the medium. Plant leaves were exposed to (11)C or (14)C-labelled carbon dioxide to investigate the effects of 5 mM nitrate on the translocation and distribution of photosynthates to nodules and roots. Supplying 5 mM nitrate stimulated the translocation rate and the distribution of labelled C in nitrate-fed parts of the roots. However, the (14)C partitioning to nodules decreased from 9% to 4% of total (14)C under conditions of 5 mM nitrate supply. These results indicate that the decrease in photoassimilate supply to nodules may be involved in the quick and reversible nitrate inhibition of soybean nodule growth.

Biological Transport↗

PubMed2003

Autonomic nerve changes in the mouse pancreas after pancreatic duct ligation.

INTRODUCTION: The mouse pancreas exhibits distinct atrophy of the exocrine tissue following pancreatic duct ligation. AIM: To investigate changes of innervation in the whole pancreas after pancreatic duct ligation. METHODOLOGY: The mouse pancreatic duct was ligated at 6 weeks of age. Pancreatic tissues were removed 7 days and 14 days after the ligation, fixed by perfusion and immersion with Zamboni solution, and embedded in gelatin. The whole organ was serially sectioned at a thickness of 100 microm, histochemically stained for cholinesterase, and observed by light microscopy. The number and volume of intrapancreatic ganglia, number of ganglion cells, and volume of each ganglion cell in the whole pancreas were quantitated. Some sections were analyzed using transmission electron microscopy after histochemically staining for cholinesterase. RESULTS: In the normal pancreas, ganglia were often situated on the outer surface of the islets of Langerhans. Thick nerve bundles ran along the arteries and emanated thin nerve fibers that surrounded the arterioles. In the atrophied pancreas following pancreatic duct ligation, ganglia remained on the islets of Langerhans as in normal mice, while the nerve fibers appeared dense, bending and curling in a more complex manner. The thin nerves also crossed each other in a complex network. Using morphometry in the pancreas following pancreatic duct ligation, the total ganglion cell number was found to decrease from normal levels. The mean ganglion cell volume in the ligated pancreas was significantly smaller than that in normal mice. As observed by transmission electron microscopy, some ganglion cells in the ligated pancreas were negative for cholinesterase activity but were surrounded by positive staining around the surface. CONCLUSIONS: These results suggest that the function of pancreatic ganglion cells changes with organ atrophy after pancreatic duct ligation.

Animals↗

PubMed2003

Novel biological activity of the region (106-126) on human prion sequence.

We report that the synthetic peptide Prp106-126 (KTNMKHMAGAAAAGAVVGGLG-COOH) and the reversed peptide Prp126-106 (GLGGVVAGAAAAGAMHKMNTK-COOH) of human prion (hPrp) can express the decarboxylase activity for oxaloacetate in the presence of trifluoroethanol, similar to that of Oxaldie 1 (LAKLLKALAKLLKK-CONH2) reported previously. The degree of the relative activity of Prp106-126 and Prp126-106 to Oxaldie 1 is 0.47 and 0.21, respectively. Based on this experimental result, we applied the informational system method (ISM) developed by Veljkovic et al. to the amino acid sequence of Prp106-126 and Prp126-106 to extract a common factor. The same spectra were obtained, indicating that the same periodicity may be conserved on their sequences, as a necessary factor for expressing the same biological activity, irrespective of the orientation of the primary sequence.

Amino Acid Sequence↗

PubMed2003

A randomized controlled trial of postoperative adjuvant immunochemotherapy for colorectal cancer with oral medicines.

Postoperative adjuvant chemotherapy reportedly improves advanced colorectal cancer patients' survival, however, it is necessary to assess what regimens are useful. Doxifluridine (5'-DFUR) is an intermediate of capecitabine approved in Europe and USA to treat metastatic colorectal cancer. 5'-DFUR is metabolized to 5-fluorouracil (5-FU) by thymidine phosphorylase existing in tumor at high concentrations, suggesting high 5-FU levels in tumor tissues and lesser complications. Present study compared usefulness of 5'-DFUR to that of oral 5-FU. Patients were enrolled at 38 centers from April 1993 to September 1996. They had diagnosed colorectal cancer of TNM stages II and III, and underwent macroscopic curative resection. Patients were prestratified into colon or rectum cancer and allocated into either 5'-DFUR (5'-DFUR 460 mg/m(2)/day + PSK 3 g/day) or 5-FU (5-FU 115 mg/m(2)/day + PSK 3 g/day) group by dynamic randomization (stratification factors such as depth of tumor, degree of lymph node metastasis, and location of tumor). Drugs were orally administered daily from postoperative week 2 to 54, with 6 mg/m(2) mitomycin C at operation and following days. Subjects for analysis were 277 in 5'-DFUR and 281 in 5-FU groups. Median follow-up was 6.5 years. Although no differences in overall survival curves were detected, multivariate analysis showed that 5'-DFUR + PSK regimen was a significantly better prognostic factor in patients with Dukes B or C (risk ratio, 1.451; p=0.048); with tumor depth of pT3 or pT4 (risk ratio, 1.568; p=0.020). For patients with advanced colorectal cancer, 5'-DFUR + PSK therapy may possibly be more useful than 5-FU + PSK, but further study is required.

Adjuvants, Immunologic↗

PubMed2002

Delayed-onset amnesia caused by protein synthesis inhibition in odor-taste associative memory of the terrestrial slug Limax valentianus.

The terrestrial slug Limax avoids the odor of innately preferred food after it is presented with the aversive taste of quinidine. This type of associative memory persists for several weeks. We investigated effects of protein synthesis inhibitors on the retention of this odor-taste associative memory. Anisomycin or cycloheximide applied to the slug 30 min prior to conditioning impaired the memory retention as late as two or more days after the conditioning, while the retention of a short-term memory was normal for up to 24 h. In contrast, the inhibition of protein synthesis by these inhibitors decays within several hours. In Limax, the onset of amnesia is unusually delayed when protein synthesis is suppressed at the time of conditioning.

Amnesia↗

PubMed2002

Induction of apoptosis after stent implantation in canine portal vein.

The purpose of this study was to analyze apoptosis in the vessel wall after stent implantation in the canine portal vein and also to investigate the expression of the p21 cyclin-dependent kinase inhibitor, which may regulate cellular proliferation after vascular injury. Uninjured, control veins had few detectable TUNEL-positive cells in the intima and media (0.829 +/- 0.413%). At 4 weeks after stent implantation, TUNEL-positive cells significantly increased to 50.5 +/- 4.639%. These cells were predominantly located around the stent struts, and appeared to be smooth muscle cells morphologically. At 12 weeks, 44.7 +/- 6.178% of the intimal and medial cells were still TUNEL positive, and there was no significant difference between 4 and 12 weeks. P21 was not detected in uninjured, normal veins. At 4 and 12 weeks after stent implantation, positive p21 immunostaining was sparsely expressed in the intima and media adjacent to the stent struts. Thus, stent implantation induced a prolonged apoptotic response and increased expression of p21 in the portal venous system. This prolonged apoptotic response, possibly regulated by p21, may have a significant role in modulating the cellularity of intimal formation.

Animals↗

PubMed2002

Visualization of thermally fluctuating surface structure in noncontact atomic-force microscopy and tip effects on fluctuation: theoretical study of Si(111)-(square root[3] x square root[3])-Ag surface.

We investigated noncontact atomic-force microscopy (NC-AFM) images of a thermally fluctuating surface structure together with tip effects based on the first-principles electronic state calculation. As an example the Si(111)-(square root[3] x square root[3])-Ag (square root[3]-Ag) surface is studied. We have succeeded in theoretically visualizing the thermal fluctuation of the square root[3]-Ag surface at room temperature, and in reproducing the observed NC-AFM image for the first time. Further, the pinning effect of the thermal fluctuation of the square root[3]-Ag surface by the tip is clarified, which shows a novel ability of NC-AFM to modify the surface structure.

Journal Article↗

PubMed2002

Inflammatory myofibroblastic tumor (IMT) of the pancreas.

Inflammatory myofibroblastic tumor (IMT) is an uncommon mass lesion composed of a variety of inflammatory and other mesenchymal cells. Although IMT was originally reported in the lung, it is now recognized that IMT can occur in a variety of organs. The occurrence of IMT in the pancreas, however, is rare. Here, we report a case of IMT arising from the head of the pancreas in a 55-year-old man. He underwent pancreaticoduodenectomy, with the diagnosis of carcinoma of the pancreas; the pathological diagnosis of the tumor was IMT. By referring to previously reported cases, we conclude that, in the management of IMT in the pancreas, surgical excision is the primary choice, in order to obtain a definitive diagnosis as well as to relieve symptoms, and strict follow-up after surgery is required.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed2002

Surgical procedures for digestive fistulae caused by radiation therapy.

PURPOSE: We evaluated the effectiveness of surgery to treat ileal fistulations associated with radiation exposure. SUBJECTS. An ileal fistula developed in eight patients, 13-102 months after 60 Gy of irradiation to the pelvic cavity, given as initial treatment or supportive therapy following resection of the primary tumor. The underlying diseases were cervical cancer in seven women and bladder cancer in one man. RESULTS: Two patients had an ileorectal fistula, two had an ileosigmoidal fistula, three had an ileovesical fistula, and one had an ileourethral fistula. We performed a partial enterectomy in one patient, a simple bypass operation without exclusion in one, and bypass operations with exclusion in the other six. Intestinal expansion in the exclusion site occurred in one patient, but there were no other complications related directly to surgery, such as sutural insufficiency. The patient who underwent a simple bypass operation died of emaciation 2 months after the surgery, but all of the other patients were discharged capable of oral ingestion. CONCLUSION: Our findings showed that surgery was beneficial for alleviating the various conditions related to digestive fistulation following radiation therapy.

Adult↗

PubMed2002

A single-base deletion in soybean flavonoid 3'-hydroxylase gene is associated with gray pubescence color.

The T locus of soybean (Glycine max (L.) Merr.) controls pubescence and seed coat color and is presumed to encode flavonoid 3'-hydroxylase (F3'H). The dominant T and the recessive t allele of the locus produce brown and gray pubescence, respectively. PCR primers were constructed based on the sequence of a soybean EST clone homologous to the F3'H gene. A putative full-length cDNA, sf3'h1 was isolated by 3' and 5' RACE. Sequence analysis revealed that sf3'h1 consists of 1690 nucleotides encoding 513 amino acids. It had 68% and 66% homology with corresponding F3'H protein sequences of petunia and Arabidopsis, respectively. A conserved amino acid sequence of F3'H proteins, GGEK, was found in the deduced polypeptide. Sequence analysis of the gene from a pair of near-isogenic lines for T, To7B (TT, brown) and To7G (tt, gray) revealed that they differed by a single C deletion in the coding region of To7G. The deletion changed the subsequent reading frame resulting in a truncated polypeptide lacking the GGEK consensus sequence and the heme-binding domain. Genomic Southern analysis probed by sf3'h1 revealed restriction fragment length polymorphisms between cultivars with different pubescence color. Further, sf3'h1 was mapped at the same position with T locus on LG3(c2). PCR-RFLP analysis was performed to detect the single-base deletion. To7B and three cultivars with brown pubescence exhibited shorter fragments, while To7G and three cultivars with gray pubescence had longer fragments due to the single-base deletion. The PCR-RFLP marker co-segregated with genotypes at the T locus in a F2 population segregating for the T locus. The above results strongly suggest that sJ3'h1 represents the T gene of soybean responsible for pubescence color and that the single-base deletion may be responsible for gray pubescence color.

Alleles↗

PubMed2002

Antioxidative collagen-derived peptides in human-placenta extract.

Human-placenta extract (PLx), has been widely used in clinical and cosmetic fields, and is known to possess marked antioxidant activity. We have attempted to identify the antioxidative components in PLx. Initially, we purified PLx using Sephadex G-10 column. The first eluted peak which had optical density at 280nm and exhibited approximately 20 per cent of antioxidant activity of the applied PLx, did not contain uracil, tyrosine, phenylalanine, or tryptophan which are the previously identified antioxidants from PLx. This fraction was further purified by reverse-phase high performance liquid chromatography. All eluted peaks containing antioxidant activity exhibited optical density at 280nm. Six separate fractions of eluent having antioxidant activity were analyzed by an amino acid sequencer, and each turned out to contain Glycine(G)-XY amino acid repeats, which appear to be derived from collagen. These results suggest that peptides produced from collagen are also antioxidative components of PLx.

Adult↗

PubMed2002

Halomicrobium mukohataei gen. nov., comb. nov., and emended description of Halomicrobium mukohataei.

Haloarcula mukohataei, previously isolated from soils of salt flats in Argentina, was originally placed in the genus Haloarcula on the basis of 16S rRNA gene sequence comparison. However, its morphology and polar lipid composition differs from that of the other Haloarcula species. In addition, its phylogenetic distance from other Haloarcula species is rather large, and the 16S rDNA sequence does not contain many of the signature bases characteristic of the genus. Transfer of the species to a new genus was therefore recommended by the International Committee on Systematic Bacteriology Subcommittee on the taxonomy of Halobacteriaceae. A full description of the isolate, proposed as a member of a new genus, Halomicrobium, as Halomicrobium mukohataei comb. nov., is presented. The type strain is strain arg-2T (= JCM 9738T = DSM 12286T = ATCC 700874T = NCIMB 13541T).

DNA, Archaeal↗

PubMed2002

Two types of network oscillations and their odor responses in the primary olfactory center of a terrestrial mollusk.

We identified two classes of network oscillations with different frequency ranges in the tentacle ganglion (TG), the primary olfactory center of the terrestrial mollusk Limax marginatus, and investigated the responses of these oscillations to odor inputs. A recent study indicated that there are serotonergic terminals in the TG. We found that when serotonin was applied to the TG, the spontaneous network oscillation of about 1.5 Hz in the TG changed its oscillatory frequency to 0.5 Hz. These two oscillations are distinct, because 1) in most cases, the application of serotonin to the TG initially inhibited the 1.5-Hz oscillation and subsequently generated the slow 0.5-Hz oscillation; and 2) occasionally, the application of serotonin did not inhibit the spontaneous 1.5-Hz oscillation, resulting in the coexistence of two network oscillations. Thus the TG has two different oscillatory dynamics. We named the spontaneous 1.5-Hz oscillation the fast oscillation (FO), and the serotonin-induced 0.5-Hz oscillation the slow oscillation (SO). By calculating the spatial coherence of the TG oscillations, we found that the FO is a noncoherent oscillatory mode and the SO is a coherent oscillatory mode. Finally, odor presentation to the olfactory receptors selectively modulated the SO by decreasing the oscillatory amplitude, but the FO was not modulated by the odor input. These results indicate that 1) the TG has two oscillatory states (FO and SO) and these states are changed by the extracellular level of serotonin, and 2) these two oscillatory states have different responses to odors.

Animals↗

PubMed2002

Contribution of nitric oxide to potassium bromate-induced elevation of methaemoglobin concentration in mouse blood.

Bromate, an inorganic oxyhalide disinfection by-product, is known to cause kidney damage, haemolysis and methaemoglobinemia. In potassium bromate (KBrO3)-treated mice (1.2 mmol/kg), elevation of methaemoglobin (MetHb) concentration in blood was observed simultaneously with an elevation of the NO concentration and attenuation of glutathione peroxidase (GPx) activity. Renal oxidative stress and kidney damage were also confirmed in the KBrO3-treated mice. A pre-administered GPx-mimic ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) dose-dependently diminished the KBrO3-induced changes in MetHb concentration and GPx activity. Renal oxidative stress and kidney damage caused by the KBrO3 administration were also dose-dependently suppressed by ebselen. On the other hand, ebselen did not suppress the KBrO3-induced elevation of the NO concentration. KBrO3-induced methaemoglobinemia, renal oxidative stress and kidney damage, consequently, seemed to result from the attenuation of GPx activity. Besides, the enhancement of NO production was not likely to be a result but a cause for the KBrO3-induced attenuation of GPx activity. In in vitro experiments, oxidation of human oxyhaemoglobin (HbO2) to MetHb was observed in a reaction mixture containing HbO2 and an NO donor, NOC-7 (1-hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene) or SIN-1 (3-(4-morpholinyl)sydnonimine), and this oxidation was inhibited by the NO scavenger carboxy-PTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide). However, no MetHb formation was observed in a reaction mixture containing HbO2 and KBrO3. These results suggest that KBrO3-induced methaemoglobinemia results from the reduction of GPx activity in blood by the KBrO3-induced increases in superoxide, NO and ONOO-.

Animals↗

PubMed2002

L-tryptophan as an antioxidant in human placenta extract.

An antioxidant was purified from human placenta extract (HPE) by using gel filtration, liquid-liquid extraction, silicagel column chromatography, and HPLC. The purified antioxidant was identified to be L-tryptophan (L-Trp). L-Trp showed higher inhibitory activity than mannitol and DMSO on the Fenton reaction-induced degradation of 2-deoxy-D-ribose. L-Trp also had much higher inhibitory activity on the cytochrome P-450-dependent lipid peroxidation than the previously identified antioxidants of HPE, L-phenylalanine, L-tyrosine and uracil. On the other hand, the inhibitory effect of L-Trp on the Fenton reaction-induced protein oxidation was smaller than that of uracil. These results suggest that L-Trp is a main antioxidant of HPE of which the effect is based on the suppression of lipid peroxidation in the oxidative stress status.

Analysis of Variance↗