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Biomedical subjects

K Inaba

Publications and source records attributed to K Inaba.

At least 91 records · Page 5Linked to original sources
PubMed1997

Hepatic damage influences the decay of nitroxide radicals in mice--an in vivo ESR study.

To determine the role of the liver in the elimination of free radicals from the body, the clearance rate (K) of nitroxide radicals (Tempol) at the hepatic domain was compared with that at the pelvic domain of live mice, using L-band ESR spectroscopy. The reduction of Tempol in biopsy specimens (liver tissue and femoral muscle) and blood obtained from Tempol-treated mice was also monitored using X-band ESR spectroscopy. Results indicated that the reduction of nitroxide radicals was delayed in both the liver and peripheral tissues when the liver was damaged. The decrease in both blood supply and reductants in the damaged liver might be involved in delaying the reduction in the whole body, because the liver can reduce the radicals supplied via the blood from the peripheral tissues, and the reductants such as reduced, glutathione in the peripheral tissues are supplied from the liver.

Animals↗
PubMed1996

Evidence of a direct action of taurine and calcium on biological membranes. A combined study of 31P-nuclear magnetic resonance and electron spin resonance.

To determine the actions of taurine and calcium on biological membranes, the effects of these compounds on the mobility of phospholipids of resealed and sonicated ghosts of human erythrocytes were investigated, using 31P-NMR spectroscopy. In addition, the effects of taurine and calcium on lipid fluidity were investigated by ESR spectroscopy, using a spin-labeling method with 5-doxyl stearic acid. The mobility of the membranes decreased following treatment with 10 mM taurine, but coadministration of 2.5 mM calcium blocked this effect. The fluidity of the membranes was not changed following treatment with 10 mM taurine, but decreased following coadministration of 2.5 mM calcium. These actions of taurine and calcium on the dynamics of biological membranes might explain, in part, the observation that most of the pharmacological effects of taurine on mammalian organs occur in the presence of calcium ions.

Calcium↗
PubMed1996

An improved isolation method for murine migratory cutaneous dendritic cells.

Dendritic cells are highly specialized accessory cells for the initiation of primary immune responses. They occur as trace populations in non-lymphoid and lymphoid organs. Therefore, the isolation and enrichment of primary dendritic cells is difficult and time-consuming. This applies also to dendritic cells from skin, i.e. epidermal Langerhans cells and dermal dendritic cells. Recently introduced skin organ cultures serve as a convenient source for primary cutaneous dendritic cells. We report here a refinement of such cultures in which cutaneous dendritic cells emigrate spontaneously into the culture medium. Murine ear skin is cultured for a total of 3 days in three sequential 24 h steps. This simple modification doubles or triples the yields of dendritic cells that can be obtained and up to 30,000 dendritic cells can be recovered from one ear half. This represents 50-70% (range 30-80%) of all viable cells. The cells are mature dendritic cells that possess potent T cell stimulatory function. Compared to the classical methods of preparing epidermal Langerhans cells by trypsinization this technique is easier and quicker; it does not require enzymes such as trypsin, and it yields similar numbers of mature dendritic cells. It should prove useful for further studies of dendritic cells of the skin.

Animals↗
PubMed1996

Cloning and sequencing of the gene for Na+/H+ antiporter of Vibrio parahaemolyticus.

A gene encoding an Na+/H+ antiporter was cloned from vibrio parahaemolyticus into the plasmid pBR322 and expressed in Escherichia coli cells. The gene enabled mutant E. coli cells to grow in the presence of 0.2 M NaCl (or 10 mM LiCl). These cells were originally unable to grow under such conditions because of the lack of major Na+(Li+)/H+ antiporters. We detected Na+/H+ antiporter activity due to the gene in membrane vesicles. The gene was sequenced and the deduced amino acid sequence was found to be 72% identical to the NhaB Na+/H+ antiporter of E. coli.

Amino Acid Sequence↗
PubMed1996

Normalization of diabetes by xenotransplantation of cryopreserved microencapsulated pancreatic islets. Application of a new strategy in islet banking.

To develop a requisite islet bank for the clinical implementation of an injectable bioartificial endocrine pancreas, microencapsulated islets were cryopreserved and assessed both in vitro by static glucose challenge and in a transplantation study. The insulin response of cryopreserved encapsulated rat islets was comparable with fresh islets. Transplantation of 800-900 banked rat islets resulted in the normalization of the metabolic blood glucose perturbation, body weight, and general health characteristics in 8 out of 8 diabetic mice for the study duration of 90 days. Whereas free islets are easily fragmented and lost during the freezing process, the capsule protects the fragile islets from freezing damage, increasing the retrieval rate from 79.5 +/- 9.8% to 97.2 +/- 1.3.

Animals↗
PubMed1996

Calcitonin gene-related peptide enhances apoptosis of thymocytes.

The effect of calcitonin gene-related peptide (CGRP), a neuropeptide, on the apoptosis of murine thymocytes was investigated. CGRP enhanced apoptosis of thymocytes beyond the spontaneous level at concentrations of 10(-11) M or higher, and the effect attained a plateau at 10(-9) M, mainly by stimulating cAMP formation. Implication of cAMP-independent mechanism was also suggested in the CGRP-induced apoptosis. Flow cytometric analysis revealed that CGRP caused apoptosis preferentially in CD4+8+ thymocytes. In addition, RNA and protein synthesis was required for apoptosis induced by CGRP.

Animals↗
PubMed1996

Upregulation of MHC class II antigen on dendritic cells from hepatitis B virus transgenic mice by interferon-gamma: abrogation of immune response defect to a T-cell-dependent antigen.

The experiments presented here were performed to see whether the level of expression of major histocompatibility complex (MHC) class II antigen (Ia antigen) on dendritic cells, one of the most critical antigen presenting cells (APC), influences the humoral immune response in hepatitis B virus (HBV) transgenic mice. We have reported that transgenic mice had a low responsiveness in specific antibody production to keyhole limpet haemocyanin (KLH), a T-cell dependent, HBV-unrelated antigen compared with the age, sex, and major histocompatibility-matched normal mice, due to a significantly lower T-cell stimulatory capacity of transgenic mice-derived dendritic cells, possibly as a result of significantly lower level of Ia antigen. Immunohistochemical staining has shown that treatment of transgenic mice with mouse recombinant interferon-gamma (IFN-gamma), daily for six consecutive days resulted in an increased expression of Ia antigen on splenic dendritic cells. Again, flow cytometric analyses have further confirmed the significant increase in the expression of Ia antigen on dendritic cells, isolated from transgenic mice treated with IFN-gamma compared with the same from the untreated or phosphate-buffered saline (PBS)-treated transgenic mice. Transgenic mice immunized with two optimum doses of KLH (5 micrograms/mouse) could not produce anti-KLH antibodies in sera, but injecting transgenic mice with the same doses of KLH together with IFN-gamma resulted in the production of anti-KLH antibodies in sera. Again, KLH-primed normal mice-derived T/B lymphocytes produced anti-KLH antibody, when cultured with dendritic cells from IFN-gamma-treated transgenic mice expressing a higher level of Ia antigen, but not with the same from PBS-treated or untreated transgenic mice. Treatment of transgenic mice with IFN-gamma resulted in a reduced level of hepatitis B virus (HBV) DNA in liver and in sera. These experiments have shown that the level of expression of Ia antigen on dendritic cells is a critical factor for its APC capability and its modulation of IFN-gamma may be used for immune therapy in HBV carriers.

Animals↗
PubMed1996

Is outer arm dynein intermediate chain 1 multifunctional?

The outer arm dynein of sea urchin sperm axoneme contains three intermediate chains (IC1, IC2, and IC3; M(r) 128,000, 98,000, and 74,000, respectively). IC2 and IC3 are members of the WD family; the WD motif is responsible for a protein-protein interaction. We describe here the molecular cloning of IC1. IC1 has a unique primary structure, the N-terminal part is homologous to the sequence of thioredoxin, the middle part consists of three repetitive sequences homologous to the sequence of nucleoside diphosphate kinase, and the C-terminal part contains a high proportion of negatively charged glutamic acid residues. Thus, IC1 is a novel dynein intermediate chain distinct from IC2 and IC3 and may be a multifunctional protein. The thioredoxin-related part of IC1 is more closely related to those of two redox-active Chlamydomonas light chains than thioredoxin. Antibodies were prepared against the N-terminal and middle domains of IC1 expressed as His-tagged proteins in bacteria. These antibodies cross-reacted with some dynein polypeptides (potential homologues of IC1) from distantly related species. We propose here that the three intermediate chains are the basic core units of sperm outer arm dynein because of their ubiquitous existence. The recombinant thioredoxin-related part of IC1 and outer arm dyneins from sea urchin and distantly related species were specifically bound to and eluted from a phenylarsine oxide affinity column with 2-mercaptoethanol, indicating that they contain vicinal dithiols competent to undergo reversible oxidation/reduction.

Amino Acid Sequence↗
PubMed1996

Inhibitory effects of traditional Chinese medicine Shimotsu-to and its included crude fractions on adjuvant-induced chronic inflammation of mice.

Effects of a traditional Chinese medicine, Shimotsu-to (a combined prescription of cnidium rhizome, peony root, angelica root and rehmannia root), and its included crude fractions were investigated on an adjuvant-induced chronic inflammation model of mice. The aqueous extract (30, 100 and 300 mg/kg, i.p.) of Shimotsu-to reduced the carmine content, granuloma weight, inflammation cell count and pouch fluid weight in the inflammation model, respectively. The extract of Shimotsu-to without cnidium at the same doses did not produce significant changes in these four inflammatory parameters. The same doses of extracts of Shimotsu-to without peony, and without angelica, weakly reduced these parameters, except for pouch fluid weight. The extract (30, 100 and 300 mg/kg) of cnidium significantly reduced these four parameters. The same doses of peony extract reduced carmine content, granuloma weight and pouch fluid weight, but less than those of the cnidium extract. The extract of cnidium and peony at the same doses reduced in an additive manner these inflammatory parameters in their combination. These results demonstrated that the Shimotsu-to extract reduced angiogenesis, granuloma formation, inflammatory cell migration and pouch fluid exudation in the adjuvant-induced chronic inflammation model. Cnidium represented the main ingredient for producing the anti-chronic inflammatory effects of Shimotsu-to extract. Cnidium and peony exhibited additive anti-inflammatory effects in combination.

Animals↗
PubMed1996

Benzoxazines. II. Synthesis, conformational analysis, and structure--activity relationships of 3,4-dihydro-2H-1,4-benzoxazine-8-carboxamide derivatives as potent and long-acting serotonin-3 (5-HT3) receptor antagonists.

A series of 3,4-dihydro-2H-1,4-benzoxazine-8-carboxamide derivatives was synthesized and evaluated for serotonin-3 (5HT3) receptor antagonistic activities by means of assays of 5-HT3 receptor binding and the ability to antagonize the von Bezold-Jarisch reflex in rats. Replacement of the 1,4-benzoxazine ring with a 1,4-benzthiepine ring or seven-membered ring (i.e., 1,5-benzoxepine or 1,5-benzthiepine) resulted in decreased affinity for 5-HT3 receptor. Introduction of substituents at the 2 position of the 1,4-benzoxazine ring increased the antagonistic activities (dimethyl > methyl > dihydro > phenyl). The compounds bearing a 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety as the basic part of 3,4-dihydro-2H-1,4-benzoxazine-8-carboxamide derivatives were equipotent to those bearing 1-azabicyclo[2.2.2]oct-3-yl moiety. The 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety was confirmed to adopt a boat-chair conformation on the basis of both NMR studies and X-ray analysis. In this series, endo-6-chloro-3,4-dihydro-N-(9-methyl-9-azabicyclo[3.3.1]non-3-yl)-2,2, 4-trimethyl-2H-1,4-benzoxazine-8-carboxamide showed the highest affinity for 5-HT3 receptors (Ki = 0.019 nM), and a long-lasting 5-HT3 receptor antagonistic activity as evidenced by antagonism to the von Bezold--Jarisch reflex in rats. Such a long-lasting 5-HT3 receptor antagonism would be attributed to the introduction of both two methyl groups at the 2 position of the benzoxazine ring and the 9-methyl-9-azabicyclo[3.3.1]non-3-yl moiety, which adopts the boat-chair conformation.

Amides↗
PubMed1996

Expression of CD45-restricted form B in (NZW x BXSB) F1 and MRL/Mp-lpr/lpr mice.

Expression of CD45RB on CD4+ or CD8+ cells in combination with TCRV beta usages (V beta 6, V beta 8.1, V beta 8.2, V beta 11 and V beta 17a) in normal mouse strains (BALD/c and C57BL/6) was compared with autoimmune-prone strains (NZW x BXSB) F1 and MRL/lpr) at young and old ages. The frequencies, and also the numbers of CD45RB- cells in CD4+ T cells with various TcR repertoires was significantly less in the autoimmune-prone stains at old ages, while, in normal control strains, they remained unchanged. Furthermore, CD4+/CD45RB- cells are CD44high and CD62L (L- selectin).low These findings suggest that most T cells, especially CD4+ T cells, in old W/BF1 and old MRL/lpr mice, were activated and this may reflect the elevation of autoantibodies and the progress of autoimmune status in aged autoimmune-prone mice. This will be discussed in relation to the progress of the autoimmune diseases.

Aging↗
PubMed1996

Taurine in the liver. The function of taurine conjugated with bile acids.

1. Taurine had cytoprotective effects on hepatocytes under hyperoxic or hypoxic condition in the presence of Ca2+. 2. Bile acids had toxic effects on hepatocytes; there was no significant difference in the toxicity between free bile acids and taurine-conjugated bile acids. 3. The mobility of the membranes, examined by 31P-NMR, decreased after treatment with taurine or free bile acids, but increased after treatment with taurine-conjugated bile acids. 4. The fluidity of the membranes, measured by ESR, did not change after treatment with taurine, but decreased after treatment with free bile acids and increased after treatment with taurine-conjugated bile acids. In conclusion, because most bile acids are conjugated with taurine in the liver after administration of taurine, the influence of taurine-conjugated bile acids has to be taken into consideration in estimating the functions of taurine in the liver.

Animals↗
PubMed1996

[A case of catamenial pneumothorax with elevated level of serum CA 125].

A 40-year old woman had experienced repeated spontaneous pneumothorax on the right side at the beginning of each menstrual period for one year. The level of serum CA125 was high at 60 ng/ml. Right thoracotomy revealed the presence of multiple darkly-pigmented spots and several pinhole like perforations near the central tendon of the diaphragm. The partial resection of the diaphragm was done, endometrial tissues were detected histologically. Tha patient has been asymptomatic after operation and the level of serum CA125 is normal.

Adult↗
PubMed1995

Coexpression of NF-kappa B/Rel and Sp1 transcription factors in human immunodeficiency virus 1-induced, dendritic cell-T-cell syncytia.

Productive infection of T cells with human immunodeficiency virus 1 (HIV-1) typically requires that the T cells be stimulated with antigens or mitogens. This requirement has been attributed to the activation of the transcription factor NF-kappa B, which synergizes with the constitutive transcription factor Sp1 to drive the HIV-1 promoter. Recently, we have found that vigorous replication of HIV-1 takes place in nonactivated memory T cells after syncytium formation with dendritic cells (DCs). These syncytia lack activated cells as determined by an absence of staining for Ki-67 cell cycle antigen. The expression and activity of NF-kappa B and Sp1 were, therefore, analyzed in isolated T cells and DCs from humans and mice. We have used immunolabeling, Western blot analysis, and electrophoretic mobility shift and supershift assays. T cells lack active NF-kappa B but express Sp1 as expected. DCs express high levels of all known NF-kappa B and Rel proteins, with activity residing primarily within RelB, p50, and p65. However, DCs lack Sp1, which may explain the failure of HIV-1 to replicate in purified DCs. Coexpression of NF-kappa B and Sp1 occurs in the heterologous DC-T-cell syncytia that are induced by HIV-1. Therefore, HIV-1-induced cell fusion brings together factors that upregulate virus transcription. Since DCs and memory T cells frequently traffic together in situ, these unusual heterologous syncytia could develop in infected individuals and lead to chronic HIV-1 replication without ostensible immune stimulation.

Animals↗
PubMed1995

Calcitonin gene-related peptide enhances cytokine-induced IL-6 production by fibroblasts.

The effect of calcitonin gene-related peptide (CGRP) was investigated on cytokine-induced IL-9 production by Swiss 3T3 fibroblasts. CGRP by itself had little effect on IL-6 production, and substantially enhanced that induced by IL-1 beta or TNF alpha at concentrations of 10(-8) M or higher. The action of CGRP was mediated by a CGRP-specific receptor. In contrast, calcitonin had no effect at all. A kinetic study of IL-6 activity in the culture supernatant showed that CGRP not only accelerated but also increased IL-6 production. Enhancement by CGRP of cytokine-dependent IL-6 production was ascribed to the increased accumulation of IL-6 mRNA. IL-1 beta-induced IL-6 production was maintained by CGRP after removal of IL1 beta. The addition of CGRP to the culture following stimulation with IL-1 beta or IL-1 beta plus CGRP decelerated the decay of IL-6 mRNA. These results indicate that the augmenting effect of CGRP is mediated, at least in part, by the stabilization of IL-6-specific mRNA.

3T3 Cells↗
PubMed1995

Vitellogenins of Oreochromis niloticus: identification, isolation, and biochemical and immunochemical characterization.

Two native forms of vitellogenin (EIP1 and EIP2) were identified in the plasma of Oreochromis niloticus. They were present in females and were estrogen-inducible in males. Both were phosphoglycolipoproteins and both immunoreacted with the antiserum raised against egg proteins. Two prominent bands (EIpp1 and EIpp2; corresponding to 185 and 120 kDa, respectively), observed on sodium dodecyl sulfate-polyacrylamide gels, were induced by estradiol treatment of males and immunoreacted with the antiserum against egg proteins. EIP1 and EIP2 were isolated by precipitation with Mg2+ ions and ethylenediamine tetraacetic acid, preparative polyacrylamide gel electrophoresis, and electroelution. During purification the fractions containing EIP1 and EIP2 also retained EIpp2 and EIpp1, respectively. Immunoblot analyses using affinity-purified antibodies against EIP1, EIP2, EIpp1, and EIpp2 confirmed that EIP1 and EIP2 were at least composed of EIpp2 and EIpp1, respectively. These results suggest that at least two immunochemically different proteins are induced and are secreted into the blood to serve as vitellogenin and to provide a source of nutrient for the developing embryo of Oreochromis niloticus.

Animals↗
PubMed1995

Enhancement of murine bone marrow macrophage differentiation by beta-endorphin.

The present study was performed to investigate the effect of beta-endorphin on macrophage colony-stimulating factor (M-CSF)-induced differentiation of macrophages from bone marrow cells in a semisolid culture system. beta-endorphin increased the number of macrophage colonies when bone marrow cells were cultured in the presence of M-CSF plus lipopolysaccharide (LPS). This was not the case with LPS-unresponsive C3H/HeJ mouse bone marrow cells. alpha-endorphin and gamma-endorphin were as effective as beta-endorphin in enhancing the colony formation. Exogenous interleukin-1 (IL-1), but neither IL-6 nor tumor necrosis factor (TNF), collaborated with beta-endorphin even in the absence of LPS, suggesting that IL-1 is a primary mediator of the effect of LPS. Indeed, anti-IL-1 antibody abolished the collaborative effect of beta-endorphin with LPS. Moreover, IL-1 was effective even for C3H/HeJ mouse bone marrow cells. Naloxone, an antagonist of endorphins for opioid-receptors, completely abrogated the effect of beta-endorphin. In a single-cell culture system, the collaboration between beta-endorphin and IL-1 was revealed by the increase in number and size of macrophage colonies, but collaboration between beta-endorphin and LPS did not occur. These results indicate that, in mixed cell culture, beta-endorphin acts in concert with paracrinal IL-1 induced by LPS to enhance M-CSF-dependent macrophage differentiation from immature precursor cells.

Animals↗