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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 397 records · Page 22Linked to original sources
PubMed1998

Nonadrenergic, noncholinergic relaxation mediated by nitric oxide with concomitant change in Ca2+ level in rectal circular muscle of rats.

The mediators of nonadrenergic, noncholinergic (NANC) relaxation of the circular muscle of rat rectum were examined in vitro. In the circular muscle of rat rectum, NG-nitro-L-arginine (L-NOARG) at 10 microM did not affect electrical field stimulation-induced relaxation but at 100 microM it inhibited electrical field stimulation-induced relaxation by about 75% and 1-mM L-arginine reversed the inhibition. Exogenous nitric oxide (NO) (1-10 microM) concentration dependently relaxed the circular muscle. Electrical field stimulation increased the cyclic GMP content of the circular muscle to about twice its resting level. L-NOARG, even at 10 microM, completely inhibited the electrical field stimulation-induced elevation of cyclic GMP content. However, L-arginine at 1 mM did not reverse the inhibition in cyclic GMP content. Inhibitory junction potentials (i.j.ps) induced by electrical field stimulation in the circular muscle cells were not affected by L-NOARG, 100 microM. Apamin ( < or = microM) did not affect the electrical field stimulation-induced relaxation, but almost completely inhibited electrical field stimulation-induced i.j.ps. NO (0.3-10 microM) induced relaxation of the circular muscle with a concomitant decrease in intracellular Ca2+ level ([Ca2+]i). Abundant immunoreactivity of NO synthase was found in the circular muscle layer, in addition to myenteric and submucosal plexus. The results suggest that NO induces NANC relaxation with a concomitant change in [Ca2+]i in the circular muscle of rat rectum. However, the involvement of changes in cyclic GMP level and in membrane potentials in the mechanism was not shown in the present experimental conditions.

Animals↗
PubMed1998

A Randomized Controlled Trial on the Prevention of Seroma after Partial or Total Mastectomy and Axillary Lymph Node Dissection.

BACKGROUND: Wound seroma is one of the most frequent complications of mastectomy, but an effective strategy for its prevention has not yet been established. The purpose of this study was to determine the effectiveness of delayed shoulder exercise on the prevention of wound seroma after partial or total mastectomy with axillary dissection for the treatment of cancer. METHODS: This study prospectively randomized two exercise schemes after mastectomy with axillary lymph node dissection. The immediate exercise group (n =58) started shoulder exercise on the first postoperative day. In the delayed exercise group (n =58) the movement of the upper limb was limited to usual daily activities during the first postoperative week. RESULTS: Preoperative levels of shoulder function were regained within one month when shoulder exercise was delayed for one week after operation. Significant decrease of drainage volume and lower incidence of seroma formation were seen in the delayed exercise group. CONCLUSION: These observations suggest that seven days of unrestricted moverment and avoiding active exercise of the shoulder joint, is the optimal routine reduce seroma formation after mastectomy.

Journal Article↗
PubMed1998

Chromosomal mapping and expression of the human B120 gene.

We previously reported a novel human cDNA, designated B120, containing a CAG repeat length polymorphism and many repeat units, loosely identified as YXQQP which is found in several human RNA binding proteins. In the present study, the B120 gene was mapped to human chromosome 1p35-36.1 by fluorescence in situ hybridization (FISH). Several human disorders, including that of Schnyder crystalline corneal dystrophy, have been mapped to this region by genetic linkage. Schnyder crystalline corneal dystrophy is thought to be a primary abnormality of corneal lipid metabolism, resulting in opacification secondary to lipid accumulation. In order to examine the function of B120, we introduced B120 cDNA with an expression vector into various cell lines including Cos1, C3H/10T1/2 and NIH/3T3 cells. These transfected cells exhibited small cytoplasmic spherical bodies. The cytoplasmic bodies appeared to be fat droplets on electron microscopy and histochemical staining. These findings suggested that B120 gene expression is associated with lipid metabolism, and that overexpression of B120 may result in lipid deposition in various cells, including those of fibroblastic cell lines. Since the cornea is composed of fibroblastic cells, overfunction of B120 could be related to the pathogenesis of Schnyder crystalline corneal dystrophy.

3T3 Cells↗
PubMed1998

Identification and characterization of the gene encoding a second proteolipid subunit of human vacuolar H(+)-ATPase (ATP6F).

The proteolipid domain of vacuolar H(+)-ATPase (V-ATPase) plays a major role in H+ transport in microvesicles and other acidic organelles. We have cloned the second human proteolipid of the V-ATPase (designated hATP6F), a homologue of the Saccharomyces cerevisiae proteolipid VMA16, which is an essential subunit of yeast V-ATPase. hATP6F is a hydrophobic protein with five putative transmembrane segments, having 61% amino acid identity and 83% similarity to the yeast protein, except in the N-terminus, and contains a conserved glutamic acid residue (Glu98) that is essential for H(+)-transporting activity. The gene for hATP6F (gene symbol, ATP6F), which consists of eight exons and spans approximately 3.5 kb, was isolated and mapped to human chromosome band 1p32.3 and the region 10.81 cR centromeric of the STS marker SHGC36789 (LOD = 6.75) by fluorescence in situ hybridization and radiation hybrid mapping, respectively. This is the first evidence in human of the existence of a second gene encoding a distinct V-ATPase proteolipid.

Amino Acid Sequence↗
PubMed1998

Ion chromatography on anion exchangers modified with mucopolysaccharides.

Anion exchangers modified with mucopolysaccharides, such as chondroitin sulfates and heparin, were used for the stationary phase in ion chromatography. Unusual retention behavior of anions was observed for the modified stationary phases. A 50-microM concentration of tartaric acid could separate inorganic anions in a reasonable time. The retention of analytes could be changed by changing the eluent composition.

Chromatography, Ion Exchange↗
PubMed1998

Phenylethanolamine-N-methyltransferase - immunoreactive nerve terminals afferent to the mouse substantia nigra.

In the substantia nigra pars compacta, many phenylethanolamine-N-methyltransferase immunoreactive (PNMT-ir) terminals as well as serotonin-ir terminals were observed for the first time to be very closely situated to the tyrosine hydroxylase (TH)-ir, aromatic L-amino acid decarboxylase-ir, and GTP cyclohydrolase I (GCH)-ir dopaminergic cells [Nagatsu, I., Arai, R., Sakai, M., Yamawaki, Y., Takeuchi, T., Karasawa, N. and Nagatsu, T., Neurosci. Lett., 224 (1997) 185-188]. Immunohistochemical colocalization of TH with GCH or PNMT in the somata and dendrites of TH-positive neurons in the rostral ventrolateral reticular formation of the medulla oblongata (C1 region, [Hokfelt, T., Fuxe, K., Goldstein, M. and Johansson, O., Brain Res., 66 (1974) 235-251]) was proved by a double-labeling immunofluorescence method with a confocal laser-scanning microscope, indicating that the neurons are adrenergic. These results suggest that dopaminergic neurons in the substantia nigra receive PNMT-ir, adrenergic afferents from the C1 region of the medulla oblongata.

Animals↗
PubMed1998

Up-regulation of alphaEbeta7, a novel integrin adhesion molecule, on T cells from systemic lupus erythematosus patients with specific epithelial involvement.

OBJECTIVE: To determine the possible role of a novel integrin, alphaEbeta7, in the pathogenesis of systemic lupus erythematosus (SLE). METHODS: Expression of alphaEbeta7 was examined on peripheral blood lymphocytes (PBL) from normal subjects (n = 25) and patients with SLE (n = 31), primary Sjogren's syndrome (n = 7), or polymyositis/dermatomyositis (n = 8) by cytofluorometry and/or immunoprecipitation. Adhesion of alphaEbeta7+ T cells to HSG epithelial cells was investigated using a confocal image analyzer. RESULTS: After phytohemagglutinin stimulation, expression of alphaEbeta7 on PBL, especially on CD8+ T cells, was significantly higher in SLE patients than in normal subjects (P<0.01). Elevated alphaEbeta7 expression was associated with the presence of oral ulcers or serositis (P<0.05). Activated SLE T cells with enhanced alphaEbeta7 expression strongly adhered to HSG; this adhesion was partially blocked by anti-alphaEbeta7. CONCLUSION: Expression and adhesion of alphaEbeta7 on activated PBL was significantly increased in patients with SLE with epithelial involvement. This suggests a role of this novel integrin in tissue-specific retention of activated PBL, due to increased alphaEbeta7-E-cadherin interaction, which may contribute to epithelial inflammation.

Adult↗
PubMed1998

Neospora caninum: tachyzoites express a potent type-I nucleoside triphosphate hydrolase.

We have identified type I nucleoside triphosphate hydrolase (NTPase; EC 3.6. 1.3) activity, previously thought to be restricted to the virulent strains of Toxoplasma gondii, in the cell extracts of Neospora caninum tachyzoites. Sequence analysis of a complete cDNA from Nc-1 strain indicated that N. caninum NTPases shared approximately 69% identity to the NTPases of T. gondii and are most similar to the NTPase-I isozyme. Southern blot analysis of genomic DNA and sequence analysis of two independent NTP clones from the Nc-1 strain revealed the presence of multiple genes, at least two of which are transcribed. Substrate specificity and Km values for MgATP2- and MgADP- hydrolysis for recombinant or partially purified native NcNTPase were the same as those for the type I isozyme (NTPase-I). Significantly, no type II enzyme (NTPase-II) activity for NDP hydrolysis was detected in cell extracts of N. caninum, although it is universally present in all T. gondii strains that have been tested. This intriguing difference between these two closely related apicomplexan parasites may provide insight into the function of the NTPases during intracellular parasitism.

Acid Anhydride Hydrolases↗
PubMed1998

Mutations in T cell receptor zeta chain mRNA of peripheral T cells from systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease of unknown aetiology. Although it has been reported that T cells might be responsible for the pathogenesis of SLE, it remains unclear whether immune aberrations of SLE T cells are the primary event in this pathological process. We have recently reported that tyrosine phosphorylation and expression of the T cell receptor zeta chain (TCR zeta) was significantly decreased in SLE T cells and that two SLE patients exhibited a 36 bp, exon 7 deletion of the TCR zeta mRNA. To investigate further common mutations in TCR zeta mRNA among SLE patients, mRNA was isolated from the peripheral blood T cells of two normal controls, two systemic sclerosis (SSc) patients, and eight SLE patients. TCR zeta cDNA was amplified by RT-PCR. Five out of the eight SLE patients exhibited abnormal migration patterns of the TCR zeta cDNA in PCR single stranded conformational polymorphism analysis. PCR products were ligated into pUC18 and five clones obtained were sequenced. Analysis of the nucleotide sequences revealed that all of the five pUC18 clones from the normal controls and SSc patients had the normal nucleotide sequence, whereas all eight SLE patients had mutations in TCR zeta cDNA accompanied by predicted amino acid substitutions. Mutations found in six of these patients corresponded to those of the third immunoreceptor tyrosine-based activation motif (ITAM) domain or the GTP/GDP binding site in TCR zetaThus, these mutations in TCR zeta mRNA could be responsible for the decreased expression of the TCR zeta protein in SLE T cells.

Amino Acid Substitution↗
PubMed1998

Granulomatous amoebic encephalitis caused by Acanthamoeba in a patient with systemic lupus erythematosus.

A 25-year-old chronically immunosuppressed woman with systemic lupus erythematosus (SLE) died after developing subacute granulomatous encephalitis caused by Acanthamoeba. Amoebic trophozoites were also found in the lung, suggesting a primary pulmonary focus of infection. The infectious encephalitis was difficult to differentiate from a flare-up of central nervous system lupus. This case illustrates that Acanthamoeba can cause fatal encephalitis in lupus patients, as well as in patients with acquired immunodeficiency syndrome as previously reported. To our knowledge, this is the first reported case of granulomatous amoebic encephalitis due to Acanthamoeba in a patient with SLE.

Acanthamoeba↗
PubMed1998

Serum soluble Fas/APO-1 is increased in patients with primary Sjögren's syndrome.

The aim of the study was to elucidate the involvement of Fas antigen in human autoimmune disease, by analysing serum levels of soluble Fas/APO-1 protein in patients with various autoimmune diseases, including system lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM), Behçet's syndrome and Sjögren's syndrome (SjS). The levels of soluble Fas/APO-1 in sera were quantitated by a sandwich enzyme-linked immunosorbent assay. Soluble Fas/APO-1 levels were significantly increased in serum from patients with primary Sjögren's syndrome (primary SjS) compared with control subjects. However, no significant differences in soluble Fas/APO-1 levels were noted in patients with secondary Sjögren's syndrome (secondary SjS) nor in patients with any of the other autoimmune diseases. The soluble Fas/APO-1 level in primary SjS patients with extraglandular diseases was significantly higher than that in patients without extraglandular diseases. These results suggest that soluble Fas/APO-1 protein may play an important role in the pathogenesis of primary SS.

Adult↗
PubMed1998

[Two surgical cases of right parasternal minimal incision for aortic valve replacement].

Although median sternotomy has been used as a good approach to all cardiac valves and coronary arteries, advantages of the minimal invasive cardiac operation have been reported recently. We employed the right parasternal minial incision, reported by Cosgrove et al. for two cases of aortic valve replacement. In the first case, we were able to get a good operation field and easily implanted a mechanical prosthesis. In contrast, we had some difficulties with the second case where in addition to the third and fourth cartilages, a second cartilage resection was necessary because the aortic root lay at a cephalic level. Moreover, the operation field was restricted because we left several rib cartilages to preserve the right internal thoracic artery. The cannula had to be inserted via the right atrium as we failed to insert it in the right femoral vein, and the aortic root deviated more medially than usual. From these experiences, it is important to check the position of aortic root, and if the cannula cannot be inserted in the femoral vein, cannulation via the right atrium can ve utilized in the minimal invasive cardiac operation.

Aortic Valve↗
PubMed1998

Mutations in the hepatocyte nuclear factor-1 alpha gene (MODY3) are not a major cause of early-onset non-insulin-dependent (type 2) diabetes mellitus in Japanese.

Maturity-onset diabetes of the young (MODY3), a monogenic subtype of non-insulin-dependent diabetes mellitus (NIDDM) with an early age of onset, is characterized by a primary defect in insulin secretion. Recently, it has been shown that mutations of the gene encoding the transcription factor hepatocyte nuclear factor-1 alpha (HNF-1 alpha) cause MODY3. Since NIDDM in Japanese is characterized by insulin secretory defects due to primary beta-cell dysfunction, we screened 60 Japanese nonobese subjects with early-onset NIDDM for mutations in this gene, 45 of whom had a first-degree relative with NIDDM. Direct sequencing of the ten exons and flanking introns of the gene in these subjects identified eight nucleotide substitutions including two amino acid changes, Ile-27-Leu and Ser-487-Asn, the frequencies of which were not significantly different in subjects with early-onset NIDDM and nondiabetic subjects. These results suggest that mutations in the HNF-1 alpha gene are not a major cause of early-onset NIDDM in Japanese.

Adolescent↗
PubMed1998

Effects of surfactants on glucosyltransferase production and in vitro sucrose-dependent colonization by Streptococcus mutans.

The presence of Tween 80 in media was associated with a significant increase in three glucosyltransferases(GTFs)(I, SI and S), especially GTF-I, produced by Streptococcus mutans strain PS14, indicating that the surfactant is a major cause of the enhanced GTF production observed in cultures in M4 medium. Lecithin and Tween 20 also enhanced GTF-I production, while Triton X-100 depressed it. At a lot concentration of 0.00125%, Tween 80 enhanced markedly only GTF-I production and its effect reached maximum at a concentration of 0.0025%. Water-insoluble glucan synthesis and artificial plaque formation (in vitro sucrose-dependent colonization) by PS14 were significantly enhanced by the addition of Tween 80 at concentrations over 0.00125%. These results suggest that surfactants might vary the cariogenic potential of Strep. mutans even at low concentrations.

Bacterial Adhesion↗
PubMed1998

Oral glucose challenge effects on growth and sex steroid hormones in normal women and women with hypothalamic amenorrhea.

OBJECTIVE: To investigate the effect of growth hormone (GH) on the serum levels of ovarian and adrenal sex steroid hormones in women with hypothalamic amenorrhea (HA). METHODS: A standard 75-g oral glucose tolerance test (OGTT) was performed in 12 normal women and 16 women with stress-related or weight-loss-related amenorrhea. RESULTS: Significant progressive declines in GH, testosterone (T), estradiol (E2) and dehydroepiandrosterone sulfate (DHEAS) were observed during the OGTT in the normal and HA groups. Significant positive correlations were observed between GH and T, E2 and DHEAS. The area under the curve (AUC) for the GH response was significantly greater in the HA group than in the normal group. The ratio of the AUC of insulin-like growth factor to that of GH was significantly lower in the HA group. CONCLUSIONS: Growth hormone may modify ovarian and adrenal sex steroidogenic responses to tropic hormones. A significant degree of GH resistance exists in HA patients. This GH resistance may be related to an ovulatory disturbance.

Adrenal Glands↗