Biomedical subjects

T Sudo

Publications and source records attributed to T Sudo.

At least 55 records · Page 3Linked to original sources

PubMed2000

Responses of tracheobronchial receptors to inhaled furosemide in anesthetized rats.

Inhalation of furosemide, a loop diuretic, has shown favorable effects on experimentally induced cough, bronchoconstriction, and dyspnea. The effect of inhaled furosemide on tracheobronchial receptors was studied in anesthetized, spontaneously breathing rats. Single unit or pauci unit activity was recorded from the right vagus nerve. Tracheobronchial receptors were classified into slowly and rapidly adapting receptors (SARs and RARs, respectively), based on their adaptation index (AI), which was derived from the decrease in spike frequency (sf) over 2 s, expressed as a percentage of the peak firing rate. There were 43 SARs (AI </= 25%) and eight RARs (AI >/= 50%). Inhalation of furosemide (n = 29) increased the slope of airway pressure (Paw) versus sf of SARs from 8.6 to 14.8 Hz/cm H(2)O with an increase in sf at Paw = 0 cm H(2)O from 18.0 to 49.5 Hz, resulting in an upward shift of the line. Neither inhalation of vehicle (n = 9) nor intravenous injection of furosemide (n = 5) changed this relationship. In addition, inhalation of furosemide attenuated the activity of RARs. These findings indicate that SARs are sensitized and RARs desensitized by inhalation of furosemide. We discuss possible mechanisms for this, and its relevance to clinical problems of dyspnea, bronchoconstriction, and cough.

Administration, Inhalation↗

PubMed2000

Basic helix-loop-helix transcription factors regulate the neuroendocrine differentiation of fetal mouse pulmonary epithelium.

To clarify the mechanisms that regulate neuroendocrine differentiation of fetal lung epithelia, we have studied the expression of the mammalian homologs of achaete-scute complex (Mash1) (Ascl1 - Mouse Genome Informatics); hairy and enhancer of split1 (Hes1); and the expression of Notch/Notch-ligand system in the fetal and adult mouse lungs, and in the lungs of Mash1- or Hes1-deficient mice. Immunohistochemical studies revealed that Mash1-positive cells seemed to belong to pulmonary neuroendocrine cells (PNEC) and their precursors. In mice deficient for Mash1, no PNEC were detected. Hes1-positive cells belong to non-neuroendocrine cells. In the mice deficient in Hes1, in which Mash1 mRNA was upregulated, PNEC appeared precociously, and the number of PNEC was markedly increased. NeuroD (Neurod1 - Mouse Genome Informatics) expression in the lung was detected in the adult, and was enhanced in the fetal lungs of Hes1-null mice. Expression of Notch1, Notch2, Notch3 and Notch4 mRNAs in the mouse lung increased with age, and Notch1 mRNA was expressed in a Hes1-dependent manner. Notch1, Notch2 and Notch3 were immunohistochemically detected in non-neuroendocrine cells. Moreover, analyses of the lungs from the gene-targeted mice suggested that expression of Delta-like 1 (Dll1 - Mouse Genome Informatics) mRNA depends on Mash1. Thus, the neuroendocrine differentiation depends on basic helix-loop-helix factors, and Notch/Notch-ligand pathways may be involved in determining the cell differentiation fate in fetal airway epithelium.

Aging↗

PubMed2000

[The mechanism of alteration of monoamine metabolism in brain regions in marble burying behavior-isolated housing mice and effect of oren-gedoku-to on this alteration].

The mechanism of the alteration in marble burying behavior-isolated housing (MBB-IH) mice was investigated. The determination of hypothalamus monoamine and serum corticosterone contents indicated that MBB-IH mice readily responded to the stress stimuli in conditioned fear stress. Six drugs, such as buspirone (10 mg/kg, p.o.), zimelidine (10 mg/kg, p.o.), clomipramin (10 mg/kg, p.o.), yohimbine (5 mg/kg, p.o.), ethyl beta-carboline-3-carboxylate (beta-CCE, 5 mg/kg, p.o.) and flumazenil (15 mg/kg, p.o.) were singly and/or three times administered to MBB-IH mice. Their inhibitory activity on the MBB-IH mice was considered by the use of activity profiles consisting of spontaneous locomotor activity, marble burying behavior and hypothalamus monoamine content. Using these profiles, we calculated the activities as vector in three-dimensional space, and compared the distance from the control point (DCP). DCPDOPAC and DCP5-HIAA were shortened by single administration of beta-CCE and flumazenil. Oren-gedoku-to (30 and 300 mg/kg, p.o.) shortened the DCPDOPAC and DCP5-HIAA similarly to beta-CCE. The blended crude drugs in Oren-gedoku-to, Coptis rhizome (636.0 mg/kg, p.o.), Scutellaria root (644.4 mg/kg, p.o.) and Gardenia fruit (894.8 mg/kg, p.o.) shortened the DCPDOPAC. Coptis rhizome and Scutellaria root also shortened the DCP5-HIAA. These results suggest that GABA neuron function intensely affects the alteration of MBB-IH and Oren-gedoku-to has the intrinsic benzodiazepine-like activity.

Animals↗

PubMed1999

Commitment and differentiation of osteoclast precursor cells by the sequential expression of c-Fms and receptor activator of nuclear factor kappaB (RANK) receptors.

Osteoclasts are terminally differentiated cells derived from hematopoietic stem cells. However, how their precursor cells diverge from macrophagic lineages is not known. We have identified early and late stages of osteoclastogenesis, in which precursor cells sequentially express c-Fms followed by receptor activator of nuclear factor kappaB (RANK), and have demonstrated that RANK expression in early-stage of precursor cells (c-Fms(+)RANK(-)) was stimulated by macrophage colony-stimulating factor (M-CSF). Although M-CSF and RANKL (ligand) induced commitment of late-stage precursor cells (c-Fms(+)RANK(+)) into osteoclasts, even late-stage precursors have the potential to differentiate into macrophages without RANKL. Pretreatment of precursors with M-CSF and delayed addition of RANKL showed that timing of RANK expression and subsequent binding of RANKL are critical for osteoclastogenesis. Thus, the RANK-RANKL system determines the osteoclast differentiation of bipotential precursors in the default pathway of macrophagic differentiation.

Animals↗

PubMed1999

Interaction of NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase protein, with calmodulin and PSD-95/SAP90. A possible regulatory role in molecular clustering at synaptic sites.

NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase family protein, is known to bind to C-terminal ends of N-methyl-D-aspartate receptor 2B (NR2B) through its PDZ (PSD-95/Dlg/ZO-1) domains. NE-dlg/SAP102 and NR2B colocalize at synaptic sites in cultured rat hippocampal neurons, and their expressions increase in parallel with the onset of synaptogenesis. We have identified that NE-dlg/SAP102 interacts with calmodulin in a Ca2+-dependent manner. The binding site for calmodulin has been determined to lie at the putative basic alpha-helix region located around the src homology 3 (SH3) domain of NE-dlg/SAP102. Using a surface plasmon resonance measurement system, we detected specific binding of recombinant NE-dlg/SAP102 to the immobilized calmodulin with a Kd value of 44 nM. However, the binding of Ca2+/calmodulin to NE-dlg/SAP102 did not modulate the interaction between PDZ domains of NE-dlg/SAP102 and the C-terminal end of rat NR2B. We have also identified that the region near the calmodulin binding site of NE-dlg/SAP102 interacts with the GUK-like domain of PSD-95/SAP90 by two-hybrid screening. Pull down assay revealed that NE-dlg/SAP102 can interact with PSD-95/SAP90 in the presence of both Ca2+ and calmodulin. These findings suggest that the Ca2+/calmodulin modulates interaction of neuronal membrane-associated guanylate kinase proteins and regulates clustering of neurotransmitter receptors at central synapses.

Amino Acid Sequence↗

PubMed1999

Characterization of the calcyclin (S100A6) binding site of annexin XI-A by site-directed mutagenesis.

Residues in annexin XI-A essential for binding of calcyclin (S100A6) were examined by site-directed mutagenesis. GST fusion proteins with the calcyclin binding site of annexin XI-A, GST-AXI 34-62 and GST-AXI 49-77 bound to calcyclin-Sepharose Ca2+-dependently. The mutants GST-AXI L52E, M55E, A56E and M59E lost the binding ability, whereas GST-AXI A57E retained the ability. These results demonstrate that the hydrophobic residues L52, M55, A56 and M59 on one side surface of the alpha-helix are critical for the binding. Assays with GST fusion proteins and synthesized peptides corresponding to the calcyclin binding site indicated that other regions around the calcyclin binding site are important to stabilize the conformation.

Amino Acid Sequence↗

PubMed1999

Ultrasound-guided follicle aspiration: the collection of bovine cumulus-oocyte complexes from ovaries of slaughtered or live cows.

To increase the collection efficiency of bovine cumulus-oocyte-complexes (COCs) by transvaginal aspiration, the effects of aspiration pressure and needle diameter on bovine follicular oocyte collection were assessed. Oocytes were aspirated from ovaries of slaughtered cows using 2 different diameter needles (18- or 21-gauge) with 4 different aspiration pressures (40, 80, 120 or 160 mmHg) and of live cows using 18-gauge needles with 40 or 80 mmHg, or using 21-gauge needles with 80 or 120 mmHg. The recovered oocytes were divided into 4 categories according to the surrounding cumulus cells and quality of oocytes: 1) 4 or more layers, 2) between 1 and 3 layers, 3) completely or partially denuded and 4) all others, including expanded cumulus cells and degenerated oocytes. The highest oocyte recovery rates from Categories 1 and 2 were obtained using 18-gauge needles with 40 mmHg pressure and 21-gauge needles with 120 mmHg pressure, respectively, from the ovaries of slaughtered cows. When oocytes were collected from live cows, the highest recovery rates for Categories 1 and 2 were obtained using an 18-gauge needle and 40 mmHg pressure, and 21-gauge needle and 80 mmHg, respectively. In addition, the proportion of oocytes in each category were compared between ovaries from slaughtered and live cows. The proportion of Category 1 oocytes collected from live cows was lower than from slaughtered cows when 18-gauge needles at 80 mmHg (P<0.05). The results show that the combination of aspiration pressure and needle diameter is crucial for COC collection, and they suggest that optimal aspiration conditions for ovaries of slaughtered cows are not necessarily applicable to live cows.

Animals↗

PubMed1999

Gene therapy by transforming growth factor-beta receptor-IgG Fc chimera suppressed extracellular matrix accumulation in experimental glomerulonephritis.

BACKGROUND: The evidence that transforming growth factor-beta (TGF-beta) is a key mediator in the pathogenesis of fibrotic diseases is now supported by several lines of investigation. This evidence provides a certain base for targeting TGF-beta as an antifibrotic agent. METHODS: We generated a chimeric cDNA, termed TGF beta RII/Fc, encoding an extracellular domain of the TGF-beta type II receptor fused to the IgG-Fc domain, and tested whether TGF beta RII/Fc could be a novel strategy for treating glomerular diseases. RESULTS: In cultured BNul-7 cells, recombinant TGF beta RII/Fc reversed the antiproliferative response induced by TGF-beta 1. In addition, TGF beta RII/Fc diminished the TGF-beta 1-induced production of EIIIA-positive fibronectin in cultured normal rat kidney cells. We then introduced the chimeric cDNA into the muscle of the nephritic rats by the hemagglutinating virus of Japan liposome-mediated gene transfer method in order to block the TGF-beta activity in nephritic glomeruli through systemic delivery of chimeric molecules. Treatment with TGF beta RII/Fc gene transfection could suppress the glomerular TGF-beta mRNA in nephritic rats with a comparable effect in the reduction of extracellular matrix accumulation. CONCLUSION: TGF beta RII/Fc successfully inhibited the action of TGF-beta in vitro and in vivo, and gene therapy by chimeric TGF beta RII/Fc might be feasible for the therapy of glomerulosclerosis.

Animals↗

PubMed1999

Increase production of lactonizing lipase (LipL) from Pseudomonas sp. strain 109 by lipids and detergents.

LipL of Pseudomonas sp. strain 109 is a unique lipase capable of catalyzing macrocyclic lactone synthesis using omega-hydroxyfatty acid esters as substrates. Several fatty acid esters were tested as inducers of LipL production. The addition of either soybean oil or a non-ionic detergent (Noigen HC) resulted in a 44 to 45-fold increase in extracellular LipL, and the presence of both resulted in a further 56-fold increase. Among the triglycerides tested, triolein was the most effective, with a 50-fold increase in LipL production. A Northern blot hybridization analysis found that the lipL transcript increased in the presence of soybean oil or Noigen HC, indicating that the production of LipL is regulated at the transcriptional level.

Amino Acid Sequence↗

PubMed1999

Tumor angiogenesis factors produced by cancer cells.

Tumor angiogenic activity from tumor angiogenesis factors (TAFs) produced by 25 cell lines was assayed onto chorioallantoic membranes (CAMs). Neovascularization occurred prominently in such cell lines, as HTBOA (poorly differentiated ovarian carcinoma), HUOCA-II (poorly differentiated clear cell adenocarcinoma), HWUA (poorly differentiated endometrial adenocarcinoma), HKUS (uterine cervical small cell carcinoma), and in HOTHC (anaplastic thyroid carcinoma). The cell lines which secreted TAF showed high heterotransplantability in nude mice and produced rapidly growing tumors which were rich in blood vessels. The TAFs polypeptides of 14,000 and 78,000 molecular weight, were extracted and purified from the conditioned medium of HUOCA-II or W3UF (sub-line of HUOCA-II) lines, respectively. TAFs at concentrations of 10 ng/ml and 100 ng/ml promoted proliferation of the endothelial cells and induced tube formation. Microsequencing analysis revealed that TAF of 78,000 molecular weight has sequence identity with human hepatocyte growth factor (hHGF).

Angiogenesis Inducing Agents↗

PubMed1998

Promotion of early osteoclastogenesis and B lymphopoiesis in the bone marrow of transgenic rats with the env-pX gene of human T-cell lymphotropic virus type I.

Human T-cell lymphotropic virus type I (HTLV-I) is associated with various clinical disorders including adult T cell leukemia, myelopathy, arthropathy. Hypercalcemia resulting from osteoclast activation and a variety of hematopoietic abnormalities have been also observed in HTLV-I infected patients, however, precise mechanism about initial trigger(s) prior to presenting symptoms is still unknown. In this study, to assess effects of HTLV-I on hematopoiesis, we analysed characteristics of early hematopoietic precursors in HTLV-I env-pX transgenic rats. Progenitor cells for osteoclasts were significantly increased even in the marrow of asymptomatic env-pX rats. Progenitors for B cells were also highly enriched, while colony forming cells (CFC) elicited by GM-CSF(CFU-GM) and M-CSF(CFU-M) were comparable to normal littermates. Following arthritis in env-pX transgenic rats, osteoclastogenesis was further augmented and the CFCs were increased. Bone marrow cells carrying adjuvant-induced arthritis retained a constant number of progenitors for osteoclast and B lymphocytes, whereas the number of CFU-GM and CFU-M increased. These results indicate that the env-pX transgene affect early stages of osteoclast and B-cell lineages prior to developing diseases, in contrast, an increase of the CFCs was caused indirectly by arthritis. This study provides a novel standpoint for the mechanisms of pathogenesis by HTLV-I.

Animals↗

PubMed1998

Identification of a novel human homolog of the Drosophila dlg, P-dlg, specifically expressed in the gland tissues and interacting with p55.

We have identified a novel human homolog of the Drosophila dlg tumor suppressor gene, termed P-dlg, which has been mapped at chromosome 10q23. Unlike other human dlg homologs, P-dlg is expressed in placenta and various gland tissues but not in brain. The P-dlg protein is localized at the plasma membrane and cytoplasm, and it is expressed in the gland epithelial cells in normal prostate tissue but not in prostate cancer cell lines. Furthermore, we identified interaction between P-dlg and p55 palmitoylated membrane protein by yeast two-hybrid screening. These findings suggest that P-dlg forms a complex with p55 at the plasma membrane and plays roles in maintaining the structure of epithelial cells and transmitting extracellular signals to the membrane and cytoskeleton, which may negatively regulate cell proliferation.

Amino Acid Sequence↗

PubMed1998

Regulation of calcyclin (S100A6) binding by alternative splicing in the N-terminal regulatory domain of annexin XI isoforms.

Annexin XI is a Ca2+/phospholipid-binding protein that interacts with a member of S100 protein family, calcyclin (S100A6), in a Ca2+-dependent manner. There are two isoforms of annexin XI, annexin XI-A and -B, generated by alternative splicing in the N-terminal regulatory domain. To determine the role of the alternative splicing region in the calcyclin-binding, we identified and characterized its calcyclin binding site. Experiments with glutathione S-transferase fusion proteins with N-terminal sites of annexin XI-A showed the calcyclin binding site to be in residues Gln49-Thr62 of rabbit annexin XI-A, which contains part of the splicing region. A synthesized peptide corresponding to Tyr43-Thr62 of annexin XI-A inhibited the interaction of annexin XI with calcyclin in liposome co-pelleting assay. The calcyclin binding site possesses a hydrophobic residue cluster conserved among S100 binding sites of annexin I and II. Recombinant annexin XI isoforms were expressed in Sf9 cells using a baculovirus expression system. In contrast to annexin XI-A, it was found that annexin XI-B protein could not bind to calcyclin by the liposome co-pelleting assay. In Sf9 cells coexpressing calcyclin with annexin XI isoforms, the calcyclin binding was observed only for annexin XI-A isoform. These results indicate that the calcyclin binding ability of annexin XI is an annexin XI-A isoform-specific character, suggesting that annexin XI isoforms might play distinct roles in cells through each alternative splicing regions.

Alternative Splicing↗

PubMed1998

MHC class I bound peptides of a colon carcinoma cell line, a Ki-ras gene-targeted progeny cell line and a B cell line.

MHC class I associated peptides on cancer cells represent potential targets for CD8+ cytotoxic T cell activity against tumor cells. We eluted the naturally bound MHC class I peptides of a colon carcinoma cell line and compared them to peptides isolated from a B cell line and a slow-growing activated Ki-ras-disrupted colon cancer cell line. While we failed to detect any significant differences in class I associated peptides due to the presence or absence of activated Ki-ras in colon cancer cell lines, the colon cancer cell lines and B cell line presented vastly different peptide repertoires in the context of HLA-A*0201 molecules.

B-Lymphocytes↗

PubMed1998

An HLA-binding-motif-aided peptide epitope library: a novel library design for the screening of HLA-DR4-restricted antigenic peptides recognized by CD4+T cells.

Susceptibility to a series of autoimmune diseases is strongly associated with particular HLA class II alleles. Identification of T cell clones and antigenic epitopes bound by HLA class II molecules involved in autoimmune diseases is critical to understanding the etiology of these HLA class II-associated diseases. However, establishment of T cell clones in autoimmune diseases is difficult because the antigenic peptides are unknown. Peptide library methods which include all possible peptide sequences offer a potentially powerful tool for the detection of cross-reactive antigenic peptides recognized by T cells. Here, we reduced the number of peptides per mixture by utilizing the known binding motifs of peptides for the HLA-DRB1*0405 molecule and evaluated the effectiveness of this library design. Each library mixture evoked a strong proliferative response in the unprimed peripheral blood lymphocytes (PBL) from HLA-DRB1*0405-positive donors but little or no response in the PBL from HLA-DRB1*0405-negative donors. The library also detected antigenic peptides that activated three antigen-specific T cell lines restricted by HLA-DRB1*0405, with different specificities. The motif-based approach thus presents a powerful method for monitoring T cells in large, heterogeneous T cell populations and is useful for the identification of the mimic peptide epitopes of T cell lines and clones.

Amino Acid Sequence↗

PubMed1998

Establishment and characterization of pro-B cell lines from motheaten mutant mouse defective in SHP-1 protein tyrosine phosphatase.

Mice homozygous for the motheaten (Hcph(me)) mutation lack a functional SHP-1 protein tyrosine phosphatase, show severe immunologic dysregulation and die at an early age. Severe pneumonitis in me/me mice is associated with abnormal proliferation of macrophages and granulocytes. Overgrowth of macrophages in long term cultures of me/me bone marrow has prevented analyses of lymphopoiesis in vitro. To establish hematopoietic cell lines from me/me mice, we cultured me/me bone marrow with the PA6 stromal cell line in the presence of antagonistic antibody against the receptor (c-Fms) for macrophage colony stimulating factor (M-CSF). In these cultures, overgrowth of M-CSF-dependent macrophages was suppressed by the antagonistic antibody and other hemopoietic cell lineages were generated efficiently from me/me bone marrow. By using this culture system, we established me/me pro-B cell clones (MEBs) with rearranged DH-JH but not VH-DJH. The growth of MEB clones required IL-7 and c-Kit ligand, corresponding to normal pro-B cells which express SHP-1. MEB cells were sensitive to starvation by either IL-7 or c-Kit ligand, resulting in apoptotic death. The present culture system, which supports hematopoiesis of me/me bone marrow, provides useful tools for the determination of the role of SHP-1 in signal transduction of B lymphopoiesis.

Animals↗

PubMed1998

Development of reference procedures for broth microdilution antifungal susceptibility testing of yeasts with standardized endpoint determination.

Standard guidelines for the broth microdilution antifungal susceptibility testing of amphotericin B, flucytosine, fluconazole, miconazole and itraconazole are reported. These are a modification of the method developed by the National Committee for Clinical Laboratory Standards (NCCLS) on the following two points: standardization of the means of endpoint determination and the inclusion of miconazole and itraconazole in the testing. MIC was determined to be when the positive control had a turbidity of 0.2 at the 630 nm wavelength. The endpoint was 80% inhibition for azoles and 100% inhibition for other drugs. The method provided good reproducibility, and a wide range of MIC distribution was observed in all antifungal agents except amphotericin B.

Antifungal Agents↗

PubMed1998

Identification of B cell epitopes of a 30 kDa Babesia equi merozoite surface protein.

A 30 kDa immunodominant surface antigen (p30) of Babesia equi has been used as a diagnostic antigen. The B cell epitopes on this molecule recognized by horse sera and monoclonal antibody (MAb) against p30, 36/133.97, were determined. A synthetic peptide of p30 with amino acid sequence of 123FYQEVLFKGFEAV135 exhibited strong positive reaction with the infected horse sera. In contrast, MAb 36/133.97 recognized different region of p30, as peptide synthesized with amino acid sequence of 27ASGAVVDFQLESI39 reacted strongly. In competitive inhibition ELISA, the binding of MAb 36/133.97 to recombinant p30 was inhibited by horse antibodies, although they did not recognize same or an overlapping epitope. The data on B cell epitopes in this study may be important in improving serodiagnostic methods of B. equi infection.

Amino Acid Sequence↗