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Biomedical subjects

A Tanaka

Publications and source records attributed to A Tanaka.

At least 343 records · Page 19Linked to original sources
PubMed2000

The characteristic pattern of aminoaciduria in patients with aristolochic acid-induced Fanconi syndrome: could iminoaciduria be the hallmark of this syndrome?

BACKGROUND: In Japan the patients with Chinese herbs nephropathy (CHN), aristolochic acids-(AAs) associated renal failure, often present Fanconi syndrome. The aim of this study was to investigate the pattern of aminoaciduria in patients with AAs-induced Fanconi syndrome and to clarify whether it is different from other Fanconi syndromes reported in the literature. SUBJECTS AND METHODS: The subjects consisted of 4 patients with Fanconi syndrome due to AAs. We studied biochemical data and urinary excretion of amino acids in the 4 patients. Amino acids in their urine were analyzed by high performance liquid chromatography (HPLC). RESULTS: Three out of 4 patients showed in common very increased excretion ofproline, hydroxyproline and citruline. Last patient showed the very increased levels of proline and valine. Regarding glycine, which is considered to belong to the same group as imino acid and to be shared with high-affinity transport system ofproline, there was not very increased excretion. CONCLUSION: These findings suggest that AAs would predominantly affect the low-affinity transport system of proline in the brushborder membrane of proximal tubules because the low-affinity system is considered not to be shared with glycine transport.

Adult↗
PubMed2000

[Prognostic significance of chromosome analysis in childhood acute lymphoblastic leukemia. Children's Cancer and Leukemia Study Group (CCLSG)].

We analyzed the prognostic significance of chromosomal findings in children with acute lymphoblastic leukemia (ALL), treated according to the Children's Cancer and Leukemia Study Group protocols between 1987 and 1993. Patients were classified into 5 groups according to chromosome number. The patients with a hyperdiploid(> 50) karyotype(13%) had the best prognosis [4-year event-free survival (EFS): 83 +/- 6%], while those with a pseudodiploid karyotype (24%) had the worst prognosis(4-year EFS: 52 +/- 6%) (log-rank, p = 0.03). However, multivariate analysis revealed that the ploidy classification had no prognostic significance in terms of EFS. When patients were classified according to chromosome abnormalities, those with any type of translocation had a worse outcome (4-year EFS: 33 +/- 9%) than those with hyperdiploidy(> 50), normal diploidy, and other abnormalities(log-rank, p < 0.0001). Multivariate analysis revealed that chromosome abnormalities were an independent prognostic factor (relative risk 3.98; p < 0.0001). Patients with t(1; 19) had an EFS similar to that of patients with chromosome abnormalities other than translocations or normal diploidy. We conclude that chromosomal findings have prognostic significance, although some chromosome abnormalities lost their statistical significance after modern intensified chemotherapy. Childhood ALL should be further stratified according to chromosome classification.

Child↗
PubMed2000

[A study on the appropriate time point for the assessment of Helicobacter pylori eradication--evaluation from the re-positive rate of H. pylori after successful eradication and delayed decrease of 13C-urea breath test levels].

We attempted to evaluate the appropriate time point for the assessment of Helicobacter pylori eradication after treatment. One hundred and nine patients with gastroduodenal diseases were enrolled this study. All of them were received proton pomp inhibitor based triple therapy and diagnosed as eradication of H. pylori infection at initial assessment. They were followed up over six months. The diagnosis of H. pylori eradication was determined by rapid urease test, culture, histology and 13C-urea breath test (UBT), and the initial assessment of the eradication was performed on 31-90 days after finishing eradication therapy. Re-appearance rate of H. pylori after initial diagnosis of eradication was 4.6% (5/109), and the mean follow-up period of them was 16.3 months. The time period of initial assessment of eradication in these 5 patients were 35, 37, 42, 49 and 60 days after treatment, respectively. On the other hand, there were 6 patients who were diagnosed as failed of eradication therapy by 13C-UBT, and being success at following period. All of the 13C-UBT levels of these 6 patients were less than 10/1000 and were decreased within negative range subsequently. The time periods of initial diagnosis of these patients except one were within 2 months after treatment. It was concluded that the assessment time of H. pylori eradication should be performed over 2 months after eradication therapy.

Adult↗
PubMed2000

Telemedicine system for home automated peritoneal dialysis.

We have developed a new telemedicine system to monitor elderly and handicapped patients that use an automated peritoneal dialysis (APD) system to perform continuous ambulatory peritoneal dialysis (CAPD) at home. The system has two parts: (1) a data collection and transport system, and (2) an interview system ("View Send" system). The former is assembled from the APD cycler, an automated blood-pressure recorder, and a scale. The latter is a combination of a digital camera, television, and set-top box (a kind of computer). The APD system contains recording and data transport junctions, a monitoring device, and a data tabulation function. All data collected by the APD system are sent directly in real time to the physician's office. Patients can easily use this telemedicine system to contact the medical staff at the Saitama Medical School CAPD center and to consult concerning their condition. Furthermore, the staff can directly change the CAPD schedule (dose and duration). Seven patients, including some who are older than 90 years or who are handicapped, have been using this telemedicine system for between 1 and 6 months (average: 3 months). From our recent experience, our tentative conclusions are that (1) elderly and handicapped patients benefit from this system by being able to maintain CAPD without major problems and accidents; (2) other problems are mainly due to simple mistakes such as accidentally pushing the on and off switches; (3) quality of life is improved for the patients.

Aged↗
PubMed2000

[A case of Sjögren's syndrome with pleural effusion].

A 45-year-old woman was admitted to our hospital because of a fever. A round erythema was noted on the skin, suggesting collagen disease. Bilateral pleural effusion developed during hospitalization, and serum and pleural effusion were positive for antinuclear antibody, RA factor, anti-SS-A antibody, and anti-SS-B antibody. A diagnosis of Sjögren's syndrome was made on the basis of reduced lacrimation and the histological findings in a biopsy specimen from the lip. The cells in the pleural effusion were predominantly lymphocytes, and so a pleural lesion associated with Sjögren's syndrome was suspected, but reports of this condition have been scarce. Good therapeutic results were obtained by corticosteroid administration. Sjögren's syndrome should be considered in the differential diagnosis of pleural effusion associated with collagen disease.

Female↗
PubMed2000

Integration of proviral sequences, but not at the common integration sites of the FGF8 locus, in an androgen-dependent mouse mammary Shionogi carcinoma.

A retroviral insertional mutation, especially by mouse mammary tumor virus (MMTV), is a major cause of murine mammary tumorigenesis. Prompted by our previous finding that FGF8, an insertionally activated cellular oncogene, is highly expressed in androgen-dependent mouse mammary Shionogi carcinoma cells, we here investigated retroviral integration adjacent to the fgf8 locus in Shionogi carcinoma. In the genomic Southern blots for fgf8 and its 5'-upstream gene npm3, the hybridized fragments were identical to the host DD/Sio mice, the original Shionogi carcinoma 115 tumor, and a pair of cultured Shionogi carcinoma cell lines of SC-3 and SC-4, suggesting that no retroviral integration occurred around either loci. The genomic cloning for the fgf8 locus from SC-3 cells also confirmed no MMTV integration. In addition, npm3, which is usually coactivated with fgf8 by MMTV insertion,was not up-regulated by androgens in SC-3 cells. All these findings led us to conclude that no retroviral insertion was present at the common integration sites adjacent to the fgf8 locus in Shionogi carcinoma although we demonstrated in this study that multiple proviral sequences of MMTV, Moloney murine sarcoma virus and FBJ-murine sarcoma virus are integrated into SC-3 cells in association with their distinct promoter activity in SC-3 cells.

Animals↗
PubMed2000

[Biopsy].

We reviewed the current devices, techniques, guiding images, indications and complications of needle biopsy with CT guidance. The development of new devices such as automated cutting needle has enabled radiologists to obtain tissue specimens of good quality at biopsy. Techniques such as the tandem or coaxial method ensure more a more accurate biopsy route. And helical CT and CT fluoroscopy have markedly shortened the time required for needle biopsy. However, we sometimes encounter minor complications, and rarely major ones, during and after needle biopsy. Some of these complications may be caused by malpractice. Therefore it is important always to pay attention to the possibility of complications of needle biopsy and to minimize radiation exposures from CT fluoroscopy.

Biopsy, Needle↗
PubMed2000

Cell surface engineering of yeast: construction of arming yeast with biocatalyst.

A cell surface engineering system of yeast Saccharomyces cerevisiae has been established and novel yeasts armed by biocatalysts (enzymes-glucoamylase, alpha-amylase, CM-cellulase, beta-glucosidase, and lipase), termed "arming yeasts", were constructed. The gene encoding Rhizopus oryzae glucoamylase with its secretion signal peptide was fused with the gene encoding the C-terminal half of yeast alpha-agglutinin and expressed in S. cerevisiae. Glucoamylase was shown to be displayed on the cell surface in its active form and anchored covalently to the cell wall. S. cerevisiae itself is unable to utilize starch, while the surface-engineered yeast could grow on starch as the sole carbon source. For further improvement of the ability to directly ferment starchy materials by the cell surface-engineered yeast, engineered yeasts displaying two amylolytic enzymes on the cell surface were constructed. The gene encoding R. oryzae glucoamylase with its own secretion signal peptide and a truncated fragment of the alpha-amylase gene from Bacillus stearothermophilus with the prepro secretion signal sequence of the yeast alpha-factor were fused with the gene encoding the C-terminal half of the yeast alpha-agglutinin. The surface-engineered yeast co-displaying glucoamylase and alpha-amylase by the integration of their genes into the chromosomes could grow faster on starch as the sole carbon source than the engineered cells displaying only glucoamylase. The system was further applied to the construction of a novel cellulose-utilizing yeast by displaying cellulolytic enzymes in their active form on the cell surface of S. cerevisiae. Engineered yeasts co-displaying FI-carboxymethylcellulase (CM-cellulase), one of the endo-type cellulases, and beta-glucosidase from Aspergillus aculeatus on their cell surface were also constructed. The yeasts displaying these cellulases were given the ability to assimilate cellooligosaccharide, suggesting the possibility that the assimilation of cellulosic materials may be carried out by S. cerevisiae displaying heterologous cellulase proteins on the cell surface. The system has also been used for the cell surface display of R. oryzae lipase (ROL). Linker peptides (spacers) consisting of the Gly/Ser repeat sequence were inserted at the C-terminal portion of ROL to enhance the lipase activity. The insertion of an appropriate length of a linker peptide as a spacer is effective in the display of ROL, having the active region at the C-terminal portion, on the cell surface. Thus, cell surface engineering will be capable of conferring novel additional abilities upon living cells and will herald a new era in the field of biotechnology.

Journal Article↗
PubMed1999

Generic tendency of metal salt cytotoxicity for six cell lines.

Systematic cytotoxicity evaluation of various metallic elements may contribute to the development of new metallic biomaterials with superior biocompatibility. It is generally reported that the cytotoxicity of a chemical differs with cell lines. However, our previous study revealed a high correlation in the cytotoxicity of 43 metal salts between two murine cell lines. If there is any generic tendency toward metal salt cytotoxicity for many kinds of cells, that information is helpful for the determination of the chemical composition of new metallic biomaterials that are expected to have lower cytotoxicity. In this study, the cytotoxicity of 12 metal salts was evaluated using four cell lines, and the results were compared, including those for two other cell lines obtained in our previous study. A metal salt concentration that reduced cell viability to 50% of that without any metal salt (IC(50)) was used as an index to compare the metal salt cytotoxicity between cell lines. The correlation was statistically proved by the IC(50)s of 12 metal salts among these cell lines (p < 0.01), suggesting the existence of a generic tendency to metal salt cytotoxicity beyond cell lines. The metal salt order of toxicity from the highest was K(2)Cr(2)O(7), AgNO(3), VCl(3), SbCl(3), CuCl(2), CoCl(2), NiCl(2), ZnCl(2), Cr(NO(3))(3), FeCl(3), TiCl(4), and Al(NO(3))(3). The sensitivity for metal salt cytotoxicity differed with cell lines; IMR-32 had the highest sensitivity among the six cell lines.

Animals↗
PubMed1999

Human serum immunoglobulin G3 subclass bound preferentially to asialo-, agalactoimmunoglobulin A1/Sepharose.

As we reported before, exoglycosidase treatment of human serum IgA1 changed it to a sticky molecule. In order to examine the presence of the specific binding protein to the sticky IgA1 in human serum, IgA1, asialo-IgA1 (IgA1-S) and asialo-, agalacto-IgA1 (IgA1-SG)/Sepharose column chromatography of normal human serum was carried out. Purified hinge glycopeptide (HGP33) prepared from IgA1 was used for the preparation of HGP/Sepharose. A portion of the serum protein was bound to those columns and eluted with the buffer containing 1.0 M NaCl. About four times the amount of protein was eluted from the IgA1-SG/Sepharose column than that from IgA1/Sepharose. Most of the eluted protein was IgG, and the IgG1 and IgG3 subclasses but neither IgG2 nor IgG4 was dominant. Under the lower salt concentration, a portion of IgG was also bound to the HGP-SG/Sepharose column. The obtained results coincide well with the previous report of the co-present of IgG1 and IgG3 with deposited IgA1 in IgA nephropathy patients (Aucouturier, P., et al. (1989) Clin. Immunol. Immunopathol. 51, 338-347). Thus, the results solved the question of why the IgG3 was co-present with deposited IgA1 in IgA nephropathy patients.

Chromatography, Liquid↗
PubMed1999

Characterization of rodent liver and kidney AVP receptors: pharmacologic evidence for species differences.

Radioligand binding studies with [3H]vasopressin (AVP) were used to determine the affinities of AVP receptor agonists and antagonists for mouse liver and kidney plasma membrane preparations. Both membrane preparations exhibited one class of high-affinity binding site. AVP ligand binding inhibition studies confirmed that mouse liver binding sites belong to the V1A subtype while kidney binding sites belong to the V2 receptor subtype. The affinity of each ligand for mouse V1A receptors was very similar to that for rat V1A receptors, showing differences in Ki values of less than 3-fold. In contrast, several peptide (d(CH2)5Tyr(Me)AVP) and nonpeptide (OPC-21268 and SR 49059) ligands had different affinities for mouse and rat kidney V2 receptors, with differences in Ki values ranging from 14- to 17-fold. These results indicate that mouse and rat kidney V2 receptors show significant pharmacologic differences.

Animals↗
PubMed1999

Association between novelty seeking and dopamine receptor D4 (DRD4) exon III polymorphism in Japanese subjects.

In this study, we investigated the association between dopamine receptor D4 (DRD4) exon III polymorphism and novelty seeking in 69 Japanese women. The group of subjects with long allele (> or =5 repeats) exhibited significantly elevated novelty seeking scores in comparison with subjects lacking the long allele. By contrast, the scores for harm avoidance, reward dependence, and persistence were statistically indistinguishable in the two group of subjects. With regard to the subscales of novelty seeking, the scores for exploratory excitability and extravagance were significantly higher in subjects with the long allele than in subjects lacking the long allele. However, no significant associations with impulsiveness or disorderliness were recognized. Our results suggest that although long alleles of the polymorphic exon III repeats are low in the Japanese population, there is an association between long alleles of DRD4 exon III polymorphism and novelty seeking.

Adult↗
PubMed1999

Matrix metalloproteinase-9 production, a newly identified function of mast cell progenitors, is downregulated by c-kit receptor activation.

Mast cell precursors invade from the peripheral blood into local tissues where they differentiate to their mature phenotypes. However, the mechanism of this migration process has been unclear. We clearly demonstrated here the production and release of matrix metalloproteinase-9 (MMP-9), a matrix-degrading enzyme necessary for leukocyte transmigration, by interleukin-3-dependent mouse mast cell progenitors: bone marrow-derived cultured mast cells and IC-2 mast cells. Because several interleukin-3-independent mast cell lines with active mutations in the c-kit gene did not release MMP-9, the possible involvement of c-kit receptor activation in downregulation of MMP-9 production was predicted. c-kit receptor activation by stem cell factor led to a significant decrease in MMP-9 production of cultured mast cells and IC-2 mast cells transfected with the c-kit gene. Thus, the present results suggest that mast cell precursors are able to produce MMP-9, which may be essential for mast cell migration into tissues, and that stem cell factor may downregulate the MMP-9 production, resulting in engagement of mast cells to matrix components.

Animals↗
PubMed1999

Accommodation of foreign genes into the Sendai virus genome: sizes of inserted genes and viral replication.

Sendai virus (SeV) is an enveloped virus with a negative sense genome RNA of about 15.3 kb. We previously established a system to recover an infectious virus entirely from SeV cDNA and illustrated the feasibility of using SeV as a novel expression vector. Here, we have attempted to insert a series of foreign genes into SeV of different lengths to learn how far SeV can accommodate extra genes and how the length of inserted genes affects viral replication in cells cultured in vitro and in the natural host, mice. We show that a gene up to 3.2 kb can be inserted and efficiently expressed and that the replication speed as well as the final virus titers in cell culture are proportionally reduced as the inserted gene length increases. In vivo, such a size-dependent effect was not very clear but a remarkably attenuated replication and pathogenicity were generally seen. Our data further confirmed reinforcement of foreign gene expression in vitro from the V(-) version of SeV in which the accessory V gene had been knocked out. Based on these results, we discuss the utility of SeV vector in terms of both efficiency and safety.

Animals↗
PubMed1999

Study of the relationship between sticky human serum IgA1 and its O-glycan glycoform.

The high-affinity IgA1 toward jacalin was mostly composed of aggregated IgA1 and abundantly contained the asialo disaccharide, Galbeta1,3GalNAc, in the O-linked oligosaccharide in the hinge region [Journal of Biochemistry 120, 92-97 (1996)]. Meanwhile, the removal of sialic acid from IgA1 accelerated the aggregation of the IgA1 molecule [J. Am. Soc. Nephrol. 9, 2048-2054 (1998)]. In order to examine the nature of such a sticky IgA1, affinity chromatography using asialo-IgA1 (deSIgA1)-Sepharose was carried out. Seventeen percent of normal human serum IgA1, 27% of asialo-IgA1 (IgA1-S), and 48% of asialo-, agalacto-IgA1 (IgA1-SG) were bound to the column. Removal of the N-acetylgalactosamine residue from IgA1-SG resulted in a decreasing affinity toward deSIgA1-Sepharose. Thus, the binding ability toward the column was the highest for the IgA1-SG among the deglycosylated IgA1s. On the other hand, heat treatment of IgA1 accelerated the aggregation but decreased its binding ability toward the column. Such heat denaturation probably destroys the structure of the binding site. Since the enzymatic removal of the N-glycan sugar chains did not induce the aggregation and exhibited no effect on the binding, the incomplete O-linked sugar chain on the hinge portion should be directly related to the sticky characteristics of the IgA1 molecule. The binding was non-covalent and not strong because the asialo-, agalacto-hinge glycopeptide was eluted slightly slower than the native one from the column and the bound IgA1 was dissociated in the presence of 1 M NaCl.

Chromatography, Affinity↗
PubMed1999

Comparison of vasopressin binding sites in human uterine and vascular smooth muscle cells.

Several studies indicate that oxytocin and vasopressin receptors in the human uterus are heterogeneous. We have investigated whether oxytocin and vasopressin bind to separate receptors or one class of receptors in human uterine smooth muscle cells. [3H]d(CH2)5Tyr(Me)AVP, the vasopressin V1A receptor selective radioligand, was used for comparison of vasopressin binding sites in human uterine and vascular smooth muscle cell membranes. Both membrane preparations exhibited one class of high-affinity binding sites with Kd values of 6.44 and 0.47 nM, Bmax values of 166 and 34.8 fmol/mg protein for uterine and vascular smooth muscle cells, respectively. In vascular preparations, the selective vasopressin V1A receptor antagonist, SR 49059 ((2S) 1-[(2R 3S)-(5-chloro-3-(2-chlorophenyl)- -(3.4-dimethoxybenzenesulfonyl)-3-hydroxy-2,3-dihydro-1H-indole-2- carbonyl]-pyrrolidine-2-carboxamide), showed high affinity with Ki value of 0.98 nM, confirming that these receptors belong to the vasopressin V1A receptor subtype. On the contrary, in uterine preparations, binding of [3H]d(CH2)5Tyr(Me)AVP was more effectively displaced by oxytocin and the oxytocin receptor selective antagonist, L-371257, (1-[1-[4-[ N-Acetyl-4-piperidinyl)oxy]2-methoxybenzoyl]piperidin-4-yl]- 4H-3,1-benzoxazin-2(1H)-one), than vasopressin and SR 49059, suggesting that binding may be due to cross-reaction with the oxytocin receptors. These results suggest that human uterine smooth muscle cells express only a high density of oxytocin receptors.

Binding Sites↗
PubMed1999

Cardiovascular and renal effects of conivaptan hydrochloride (YM087), a vasopressin V1A and V2 receptor antagonist, in dogs with pacing-induced congestive heart failure.

The systemic hemodynamic and renal responses to conivaptan hydrochloride (YM087; 4'-(2-methyl-1,4,5,6-tetrahydroimidazo[4,5-d][1]benzoazepine -6-carbonyl)-2-phenylbenzanilide monohydrochloride), a vasopressin V1A and V2 receptor antagonist, were determined in pentobarbital-anesthetized dogs after 2 to 3 weeks of rapid right ventricular pacing. Congestive heart failure, characterized by decreases in first derivative of left ventricular pressure (left ventricular d P/dt(max)) and cardiac output, and increases in left ventricular end-diastolic pressure and total peripheral vascular resistance, was induced by chronic rapid right ventricular pacing at 260-280 beats/min. Intravenous administration of conivaptan (0.1 mg/kg) significantly increased left ventricular dP/dt(max) and cardiac output and significantly decreased left ventricular end-diastolic pressure and total peripheral vascular resistance. Conivaptan also increased urine flow and reduced urine osmolality by markedly increasing free water clearance. These results indicate that conivaptan produced hemodynamic improvement and marked aquaresis in dogs with congestive heart failure. Therefore, conivaptan may find clinical use in treating patients with congestive heart failure.

Animals↗