Studies on some edible and medicinal plants of Mesoamerica.
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Animals↗
Biomedical subjects
A Ito
Publications and source records attributed to A Ito.
Toxigenicity of Helicobacter pylori isolates possessing cagA gene and vacuolating cytotoxin.
Inflammatory cells in the gastric epithelium and direct cell damage are important effects of H. pylori infection in causing gastroduodenal diseases. The aim of this study was to determine whether H. Pylori possessing the cagA gene and vacuolating cytotoxin activity (cagA+/tox+) has these toxigenicities. The detection of cagA was performed by the polymerase chain reaction method. Culture supernatants of H. pylori were tested on rabbit gastric epithelial cell culture for intracellular vacuolation. H. pylori isolates were divided into two major types, cagA+/tox+ and cagA-/tox- strains. Ten Japanese monkeys were allocated to two groups, with six animals inoculated with the cagA+/tox+ strain and four animals inoculated with the cagA-/tox- strain. Five other Japanese monkeys served as controls. They were observed endoscopically every week and the severity of gastritis was evaluated in biopsy specimens obtained from the antral mucosa. Histopathological examination of the gastric mucosa revealed a more severe neutrophil infiltration caused by the cagA+/tox+ strain than that caused by the cagA-/tox- strain for 3 months after inoculation. These findings indicate that cagA and vacuolating cytotoxin may be important factors in causing the severe damage of the human gastric mucosa produced by H. pylori.
Animals↗
Urinary trypsin inhibitor suppresses the production of interstitial procollagenase/proMMP-1 and prostromelysin 1/proMMP-3 in human uterine cervical fibroblasts and chorionic cells.
The mechanisms by which urinary trypsin inhibitor (UTI) prevents preterm premature rupture of fetal membrane and premature cervical ripening were investigated. We, therefore, examined the effects of UTI on the production of matrix metalloproteinases (MMPs) which closely participate in the breakdown of extracellular matrix in cultured human uterine cervical fibroblasts and human chorionic cells. UTI suppressed specifically the production of interstitial procollagenase/proMMP-1 and prostromelysin 1/proMMP-3 from both cells in a dose-dependent manner (0.32-1.28 microM). This suppression was accompanied by a decrease in steady-state levels of their mRNAs. These results indicate for the first time that UTI down-regulates the production of proMMP-1 and proMMP-3 accompanying with the decrease in the expression of their mRNAs, and therefore UTI actually participates in the maintenance of fetal membranes and/or uterine cervix by overall suppression of MMP production along with the known inhibitory actions towards serine proteinases.
Blotting, Northern↗
Solubility product of OH-carbonated hydroxyapatite.
Information on the solubility of OH-carbonated hydroxyapatite, Ca10(PO4)6(CO3)x(OH)2-2x, previously has not been available. In the present study the solubility product (Ksp) of OH-carbonated hydroxyapatite was measured in a 0.1 M acetic acid and sodium acetate buffer solution in a pH range of 4.0-5.8 at a CO2 partial pressure of 10(-3.52) atm. The equilibrium solubility increased with the increase of carbonate content. The Ksp values decreased with the decrease of pH. For example, Ksps were 10(-119), 10(-123), and 10(-130) for pure hydroxyapatite at pH 4.9, 4.5, and 4.1, respectively. The decrease of Ksp was not accounted for by calcium-carbonate complexation. Ksp measured at isoelectric points (L) was expressed as pL = 118.65 - 0.47316 x (CO2 wt%)2.4176. From this formula, the L values were calculated for pure and fully carbonated hydroxyapatite as 10(-118.7) and 10(102.8), respectively. The L value for pure hydroxyapatite agreed with values measured under carbonate-free conditions. Therefore, the L values were regarded as the Ksp for OH-carbonated hydroxyapatite excluding errors arising from carbonate contamination in the solution.
Air Pressure↗
Donor-specific tolerance by perioperative intrathymic injection of bone marrow cells in the rat cardiac allograft model: use of FK506 can shorten the necessary duration of pretransplant intrathymic conditioning.
BACKGROUND: Many strategies of tolerance induction by intrathymic (IT) injection of donor alloantigens have been reported to date; however, the timing of IT injection is usually 1-3 weeks before transplantation. METHODS: To apply IT injection to cadaveric organ transplantation, 1 x 10(8) fully allogeneic bone marrow cells (BMC) of Buffalo (BUF; RT1b) rats were intrathymically injected into Wistar Furth (WF; RT1u) rats at the time of BUF cardiac allografting with short-course therapy of antilymphocyte serum (ALS) and FK506 in our experimental model. RESULTS: Allogeneic IT injection of BUF BMC with ALS and FK506 indefinitely prolonged graft survival (mean survival time > 210 days) in all WF rats. On day 130 after grafting, tolerant WF rats accepted donor BUF skin grafts (> 120 days) but not third-party Lewis skin grafts. In control groups, syngeneic IT injection of WF BMC or intravenous injection of donor BUF BMC in combination with ALS/FK506 therapy failed to induce tolerance. In vivo testing was performed during induction (1 month) or during maintenance (6 months of tolerance. In the mixed lymphocyte reaction (MLR), spleen T cells of tolerant rats at 1 month after grafting displayed hyporesponsiveness after stimulation with donor cells. The addition of interleukin (IL)-2 to MLR culture did not restore T-cell responsiveness. Tolerant rats had a significantly decreased frequency of T cytotoxic cell precursors (fTcp) of 1:4,926, and frequency of IL-2-producing T helper cell precursors (fThp) of 1:23,925, compared with naive rats (1: 2,158 and 1:4,266, respectively). By 6 months after grafting, however, the anti-donor MLR proliferative responses of tolerant rats had been restored to the levels of naive splenic T cells. These tolerant rats displayed restoration of the (fTcp) of 1:2,842 and of the (fThp) of 1:5,630, which were comparable frequencies of naive rats. Suppressor T cells did not contribute in this model. In cardiac grafts of tolerant rats induced by IT injection, expression of both Th1 (interferon-gamma and IL-2) and Th2 (IL-4 and IL-10) cytokines was detected in the early phase; thereafter, expression was completely inhibited, except for interferon-gamma in the chronic phase. CONCLUSIONS: Perfect donor-specific tolerance was obtained by IT injection of donor BMC at the time of transplantation, while alloimmune responses were maintained at levels similar to those of naive rats.
Adoptive Transfer↗
Substituted 3-(phenylsulfonyl)-1-phenylimidazolidine-2,4-dione derivatives as novel nonpeptide inhibitors of human heart chymase.
A series of 3-(phenylsulfonyl)-1-phenylimidazolidine-2,4-dione derivatives have been synthesized and evaluated for their ability to selectively inhibit human heart chymase. The structure-activity relationship studies on these compounds gave the following results. The 1-phenyl moiety participates in a hydrophobic interaction where an optimum size is required. At this position, 3,4-dimethylphenyl is the best moiety for inhibiting chymase and showed high selectivity compared with chymotrypsin and cathepsin G. A 3-phenylsulfonyl moiety substituted with hydrogen-bond acceptors such as nitrile and methoxycarbonyl enhances its activity. Molecular-modeling studies on the interaction of 3-[(4-chlorophenyl)sulfonyl]-1-(4-chlorophenyl)-imidazolidine-2,4-dione (29) with the active site of human heart chymase suggested that the 1-phenyl moiety interacts with the hydrophobic P1 pocket, the 3-phenylsulfonyl moiety resides in the S1'-S2' subsites, and the 4-carbonyl of the imidazolidine ring and sulfonyl group interact with the oxyanion hole and the His-45 side chain of chymase, respectively. The complex model is consistent with the structure-activity relationships.
Binding Sites↗
A hairpin-loop conformation in tandem repeat sequence of the ice nucleation protein revealed by NMR spectroscopy.
The 1H-NMR spectrum of a synthetic 24-residue peptide (A1-G-V-D-S-S-L-I-A-G-Y-G-S-T-Q-T-S-G-S-D-S-A-L-T24; INP24), comprising three repeats of the 8-residue consensus sequence of Pseudomonas syringae ice nucleation protein, was fully assigned using 2-dimensional (2D) NMR spectroscopy at 4 degrees C and 30 degrees C. Close proximity of the aliphatic protons between Leu7, Ile8, Ala9, and the ring-protons of Tyr11 was indicated from the observation of the inter-molecular nuclear Overhauser enhancement (NOE) effect. Hydrogen-bonding was strongly suggested for the NH group of Leu7 from its extremely low-temperature coefficient estimated from the temperature dependence of the chemical shift. These results indicate the formation of a hairpin-loop conformation constructed by a hexapeptide segment of INP24, -Leu7-Ile8-Ala9-Gly10-Tyr11-Gly12.
Amino Acid Sequence↗
A key amino acid responsible for substrate selectivity of monoamine oxidase A and B.
Monoamine oxidase (MAO) oxidizes biologically important amines including neurotransmitters and plays a central role in the regulation of intracellular level of these amines. Two distinct forms of MAO (MAO A and MAO B) were defined based on differences in substrate and inhibitor specificities. We earlier reported that the region between about residues 120 and 220 of rat MAO is responsible for determination of the substrate selectivity of MAO A and B (Tsugeno, Y. Hirashiki, I., Ogata, F., and Ito, A. (1995) J. Biochem. (Tokyo) 118, 974-980). To determine the essential amino acids in this region that participate in substrate recognition, a series of mutant enzymes in which amino acid residues that are conserved among various species but are different between the two forms of the enzyme were replaced with the corresponding amino acids of the counterpart and were engineered from the cDNAs of rat liver MAO A and B, and affinities for several substrates were examined. A single mutation in which Phe-208 in MAO A was substituted by the corresponding residue of Ile in MAO B was sufficient to convert the A-type substrate selectivity, and the reverse was exactly the case. Phe at this position was replaceable with Tyr for the A-type specificity and Ile was replaceable with Val and Ala for the B-type. Thus, aromatic and aliphatic residues seem to contribute to render substrate selectivity of MAO A and MAO B, respectively.
Amino Acid Sequence↗
Peripheral framework of carrot cell nucleus contains a novel protein predicted to exhibit a long alpha-helical domain.
A monoclonal antibody, CML-1, raised against carrot (Daucus carota L.) nuclear-matrix proteins selectively labeled the nuclear periphery of carrot protoplasts when visualized by confocal and electron microscopy. To identify the constituent proteins of higher plant cells structurally homologous to the vertebrate nuclear lamina, we cloned overlapping cDNAs partially encoding a CML-1-recognized protein and determined the entire sequence including the open reading frame. When the deduced amino acid sequence was compared with other known protein sequences contained in major databases, no protein was found to show high sequence identity across the whole region of the protein, while the partial sequence showed strong similarities with myosin, tropomyosin, and some intermediate filament proteins. The protein, designated NMCP1, had an estimated molecular mass of 133.6 kDa and showed three characteristic domains. The central domain contains long alpha-helices exhibiting heptad repeats of apolar residues, demonstrating structural similarity to that of filament-forming proteins. The terminal domains are predominantly nonhelical and contain potential sequence motifs for nuclear localization signals. NMCP1 has many recognition motifs for different types of protein kinases, including cdc2 kinase and PKC. These results suggest that NMCP1 protein forms coiled-coil filaments and is a constituent of the peripheral architecture of the higher plant cell nucleus.
Amino Acid Sequence↗
Fretting corrosion resistance and fretting corrosion product cytocompatibility of ferritic stainless steel.
To avoid nickel ion release from SUS317L as an implant material, a new type of nickel, commercially free, of high purity, and high chromium ferritic stainless steel, was developed. The new stainless steel (FJ) was studied for aspects of fretting corrosion and cytocompatibility compared with SUS317L. A pin-on-plate fretting corrosion test in an artificial physiologic solution, and cell culture in media with the addition of the artificial physiologic solution used for fretting was conducted. Resistance to the fretting induced crevice corrosion of FJ was higher than that of SUS317L because of the favorable electrochemical stability of the FJ alloy. The amount of iron ion or colloidal fine particles released from FJ was about a quarter of that from SUS317L, although the weight loss of a pin of FJ was almost 5/3 that of SUS317L. The artificial physiologic solution used for SUS317L fretting was more harmful to the growth of L929 and MC3T3-E1 cells than that used for FJ fretting. FJ was therefore superior to SUS317L as a biomaterial, judging from the resistance to fretting-induced crevice corrosion, electrochemical stability, and the cytocompatibility of fretting corrosion products.
3T3 Cells↗
Bending strength of synthetic OH-carbonated hydroxyapatite single crystals.
Although hydroxyapatite (HAP) is applied to medical implants because of its biocompatibility, no data on mechanical strength of HAP single crystals were yet available, partly due to the difficulty in obtaining sufficiently large single crystals. In the present study the bending strength of OH-carbonated hydroxyapatite (CHAP) single crystals containing carbonate of 0.09 CO2 wt % prepared hydrothermally was determined in three-point bending tests. The three-point bending tests were performed using a modified ultra micro-hardness tester with a span of 380 micrograms and a bending direction of <210>. The CHAP single crystals were broken in air, water, and air after immersion in alpha minimum essential medium (alpha MEM) + 10% fetal bovine serum (FBS) for 3 weeks. The average bending strength of the CHAP single crystals was 468 +/- 205, 361 +/- 199 and 501 +/- 212 MPa in air, water, and air after immersion in alpha MEM + 10% FBS, respectively. In all cases the maximum strength at each crystal thickness value decreased in inverse proportion to the thickness.
Animals↗
Postural sway frequency analysis in workers exposed to n-hexane, xylene, and toluene: assessment of subclinical cerebellar dysfunction.
To clarify the effects of organic solvents on the postural balance system, 29 male sandal, shoe, and leather factory workers exposed to n-hexane, xylene, and toluene (solvent workers) were examined by computerized static posturography with sway frequency analysis. Concentrations of metabolites of solvents in urine samples taken from the workers in the morning before work ranged from 0.41 to 3.06 (mean, 1.20) mg/g creatinine (Cn) for 2,5-hexanedione, from 0.10 to 0.43 (mean, 0.19) g/g Cn for methylhippuric acid, and from 0.05 to 2.53 (mean, 0.37) g/g Cn for hippuric acid; estimated concentrations of n-hexane in workplace air ranged from 13 to 100 (mean, 40) ppm. Control subjects were 22 healthy males without exposure to solvents. With eyes open, postural sway with a frequency of 2-4 Hz in solvent workers was significantly larger than that in controls in the anteroposterior direction. With eyes closed, sway with a frequency of 0-1 Hz was significantly larger in solvent workers in the mediolateral and anteroposterior directions. Results of multiple regression analysis showed that with eyes open the 1- to 2-Hz and 2- to 4-Hz sways were related positively to 2,5-hexanedione and inversely with methylhippuric acid. The pattern of changes suggests that the vestibulocerebellar and spinocerebellar afferent systems are asymptomatically affected by n-hexane; the effect of n-hexane on the vestibulocerebellar system is possibly inhibited by xylene.
Cerebellum↗
Regulation of autoimmune diabetes by interleukin 3-dependent bone marrow-derived cells in NOD mice.
Interleukin-3 (IL-3), a multilineage colony stimulating factor, has been shown to augment alloreactive bone marrow-derived suppressor cell activity in vivo and in vitro. The present study examined the effect of IL-3 on autoimmune-mediated diabetes in NOD mice. Administration of IL-3 twice weekly starting at 2-4 weeks of age delayed the onset and reduced the overall incidence of diabetes. Bone marrow cells obtained from IL-3-treated NOD mice protected NOD mice from cyclophosphamide-induced diabetes but failed to prevent adoptively transferred diabetes. In vitro culture of bone marrow cells in medium containing IL-3 produced a Thy-1+CD3epsilonloCD4-CD8-CD25- immature T cell clone which prevented cyclophosphamide-induced diabetes. The cloned cells also effectively delayed the development of diabetes induced by transfer of T cells in adult thymectomized, irradiated, bone marrow-reconstituted NOD mice. These results suggest that IL-3 is capable of regulating extrathymic T cell development from the bone marrow and that these cells mediate strong immunoregulatory function.
Adoptive Transfer↗
Compartmental analysis of asialoglycoprotein receptor scintigraphy for quantitative measurement of liver function: a multicentre study.
A multicentre study on multicompartmental analysis of hepatic scintigraphy using technetium-99m labelled galactosyl serum albumin (GSA), which binds to the asialoglycoprotein receptor, was carried out at seven institutions in Japan. Seventy-four patients with liver disease received 3 mg (185 MBq) of 99mTc-GSA by intravenous injection. Sequential scanning was performed 30 min after injection to obtain anterior images of the heart and liver, followed by single-photon emission tomography (SPET). The indices included in this analysis were hepatic blood flow (Q) and maximal receptor binding rate (Rmax), which showed a good correlation with semiquantitative ratio indices for 99mTc-GSA, namely the retention rate in blood (HH15) and the hepatic uptake rate (LHL15). Q and Rmax also showed a significant correlation with other measures of hepatic function. When patients were grouped according to the severity of chronic liver damage (hepatocellular functional damage), Q was reduced in the moderate and severe groups, while Rmax was reduced in proportion to the functional stage. Both parameters showed no inter-institution difference using analysis of co-variance with the functional stage as a co-variant. With regard to the hepatic uptake rate, anterior planar images and SPET images gave similar results for Q and Rmax. Acquisition times of 15 or 30 min provided the same results. The multicompartmental model analysis permitted comparable results to be obtained at institutions using different gamma cameras, and is therefore considered a universally applicable method. These results indicate that Q and Rmax are useful general indices for evaluating the functional reserve capacity of the liver.
Asialoglycoprotein Receptor↗
Strain differences in the induction of intestinal metaplasia by X-irradiation in rats.
Strain differences in the susceptibility of rats to induction of intestinal metaplasia by X-irradiation were examined. The gastric regions of 5-week-old males of five inbred strains of rats (F344/NSlc, Copenhagen, Buffalo/NacJcl, and ACI/NHos) and three strains of randomly bred rats (HOS:Donryu, Slc:Wistar, Slc:SD) were irradiated with a total dose of 20 Gy X-ray given in two equal fractions at 3-day interrals. When examined after the rats were killed, 6 months after the last irradiation, the number of intestinal metaplastic crypts positive for alkaline phosphatase (ALP) was highest in the Donryu and lowest in the Copenhagen rats. Morphologically, the number of crypts with intestinal metaplasia in the glandular stomachs of Donryu, Wistar, SD, and Buffalo rats was higher than the number in ACI, F344, and Copenhagen rats. Intestinal metaplasia was more frequently observed in the pyloric than in the fundic glands. These results demonstrate that the induction of intestinal metaplasia by X-irradiation in rats is greatly influenced by the rat strain.
Animals↗
Monte Carlo simulation of physicochemical processes of liquid water radiolysis. The effects of dissolved oxygen and OH scavenger.
The paper describes developments of the physicochemical part of a computer code system that estimates DNA strand break induction on plasmid pBR322 DNA. In order to test the reliability of the model, we evaluated the dielectric function and the time-dependent yield of chemical species in the presence of OH radical scavenger or dissolved oxygen. Results agree with measurements on the radiolysis of liquid water. When a hybrid model of a liquid inelastic cross-section and a vapour elastic cross-section is used, energy deposition by vibrational excitations is estimated to be approximately 11% of total energy deposition.
Free Radical Scavengers↗
Usefulness of contrast-enhanced endoscopic ultrasonography with intravenous injection of sonicated serum albumin.
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Albumins↗
In vitro hatched oncospheres of Asian Taenia from Korea and Taiwan develop into cysticerci in the peritoneal cavity of female scid (severe combined immunodeficiency) mice.
In vitro hatched (but not activated) oncospheres of Asian Taenia obtained in Korea and Taiwan, prepared by the sodium hypochlorite method, rinsed with sterile PBS several times and adjusted to 5 x 10(4)/0.5 ml PBS, were injected intraperitoneally or subcutaneously into male or female scid mice of 3 different strains. When these scid mice were sacrificed 4 months later, the females harboured fully developed cysticerci either in the peritoneal cavity or under the back skin, whereas males did not. All cysticerci from the peritoneal cavity were easily recovered by rinsing the abdomen with PBS. Although most cysticerci recovered from pig liver usually become calcified within 1-2 months, in female scid mice they all increased in size and were viable. Intraperitoneal (i.p.) injection of in vitro hatched oncospheres is recommended for easier recovery of Asian Taenia metacestodes in laboratory animals.
Animals↗