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Biomedical subjects

H Yoshida

Publications and source records attributed to H Yoshida.

At least 271 records · Page 15Linked to original sources
PubMed2001

Interferon-gamma stimulates fractalkine expression in human bronchial epithelial cells and regulates mononuclear cell adherence.

Bronchial epithelial cells may contribute to airway inflammation by releasing chemokines and expressing surface membrane molecules involved in the adhesion of leukocytes. We found that interferon (IFN)-gamma stimulates expression of fractalkine, a potent chemoattractant for monocytes and T lymphocytes, in a time- and concentration-dependent manner by normal human bronchial epithelial cells in culture. Enhanced expression of fractalkine messenger RNA was confirmed by both reverse transcription/polymerase chain reaction and Northern blotting. IFN-gamma also stimulated fractalkine protein production and most of the protein was found in cell lysates. The adherence of blood mononuclear cells to the monolayers of bronchial epithelial cells stimulated with IFN-gamma was partly inhibited by an antifractalkine antibody. An antibody against intercellular adhesion molecule-1 was similarly effective in inhibiting the adhesion. Fractalkine protein levels in bronchoalveolar lavage fluids from patients with inflammatory diseases correlated positively with mononuclear cell counts in the fluids. The bronchial epithelium in a biopsy specimen of lung cancer was stained positively by immunofluorescent staining for fractalkine. We conclude that IFN-gamma stimulates fractalkine expression by bronchial epithelial cells, which may play an important role in inflammatory responses by recruiting mononuclear leukocytes to the bronchial epithelium.

Base Sequence↗
PubMed2001

Alcohol consumption and risk for increased aortic pulse wave velocity in middle-aged Japanese men.

A 9-year longitudinal study was performed to prospectively examine the association of alcohol consumption with development of increased aortic pulse wave velocity (PWV) in 1,358 Japanese men aged 35 to 59 years with a PWV less than 8.0 m/sec and without antihypertensive medication. Three hundred fifty-nine men developed increased aortic PWV of 8.0 m/sec or more during 10,598 person-years follow-up. After controlling for potential predictors of aortic PWV, the relative risk for increased aortic PWV compared with that in nondrinkers was 1.05 (95% confidence interval [CI], 0.70 to 1.58) for those who drank 0.1 to 22.9 g/day of ethanol, 1.58 (95% CI, 0.89 to 1.91) for those who drank 23.0 to 45.9 g/day of ethanol, 1.77 (95% CI, 1.24 to 2.53) for those who drank 46.0 to 68.9 g/day of ethanol, and 1.81 (95% CI, 1.23 to 2.66) for those who drank 69.0 or more g/day of ethanol (p for trend <0.001). The relative risk for increased aortic PWV in current drinkers vs nondrinkers was stronger among men with a body mass index (BMI) less than 24.2 kg/m2 and nonsmokers than among men with a BMI 24.2 kg/m2 or more and current smokers, respectively. These results suggest that alcohol consumption is closely associated with risk for increased aortic PWV in middle-aged Japanese men.

Adult↗
PubMed2001

Mouse Wnt receptor gene Fzd5 is essential for yolk sac and placental angiogenesis.

Wnts are secreted signaling molecules implicated in various developmental processes and frizzled proteins are the receptors for these Wnt ligands. To investigate the physiological roles of frizzled proteins, we isolated and characterized a novel mouse frizzled gene Fzd5. Fzd5 mRNA was expressed in the yolk sac, eye and lung bud at 9.5 days post coitum. Fzd5 specifically synergized with Wnt2, Wnt5a and Wnt10b in ectopic axis induction assays in Xenopus embryos. Using homologous recombination in embryonic stem cells, we have generated Fzd5 knockout mice. While the heterozygotes were viable, fertile and appeared normal, the homozygous embryos died in utero around 10.75 days post coitum, owing to defects in yolk sac angiogenesis. At 10.25 days post coitum, prior to any morphological changes, endothelial cell proliferation was markedly reduced in homozygous mutant yolk sacs, as measured by BrdU labeling. By 10.75 days post coitum, large vitelline vessels were poorly developed, and the capillary plexus was disorganized. At this stage, vasculogenesis in the placenta was also defective, although that in the embryo proper was normal. Because Wnt5a and Wnt10b co-localized with Fzd5 in the developing yolk sac, these two Wnts are likely physiological ligands for the Fzd5-dependent signaling for endothelial growth in the yolk sac.

Amino Acid Sequence↗
PubMed2001

Prevention of the adverse effects of aprotinin in autologous fibrin glue.

To avoid the adverse effects of aprotinin (Apr) in autologous fibrin glue, we compared the inhibitory properties of four commercial anti-fibrinolytic agents (tranexamic acid (Tra), epsilon-aminocaproic acid (Ips), gabexate mesilate (Gab) and nafamostat mesilate (Naf)). The optimum conditions for the lysing of fibrin glue were an incubation temperature of 37 degrees C, and incubation medium containing urokinase at 100 U/ml and plasminogen at 100 mU/ml (for the washed glue), or neither (for unwashed glue). Fibrin glues without an anti-fibrinolytic agent were quickly lysed in the incubation medium, while those with an anti-fibrinolytic agent were slowly lysed dose-dependently. Naf was the most potent inhibitor and had high affinity for the glue, but the other agents were poor inhibitors and had low affinity. The inhibition potency (IP) of each agent did not correlate with hydrophobicity, but a good correlation was obtained between the remaining coefficient (RC) and hydrophobicity. Naf did not affect the adhesive strength of the glue. These results indicate that Naf is the most suitable anti-fibrinolytic agent to replace Apr.

Aprotinin↗
PubMed2001

Stereoselectivity and species difference in plasma protein binding of KE-298 and its metabolites.

In vitro protein binding of KE-298 and its plasma metabolites, deacetyl-KE-298 (M-1) and S-methyl-KE-298 (M-2), was high in rat (>97%), dog (>89%) and human plasma (>99%), respectively. Human serum albumin (>93%) was the main protein involved in the binding to plasma proteins, while the binding to human serum globulins was low (16-33%). The binding of KE-298 and its metabolites in all species of plasma was stereoselective. The (+)-(S)-enantiomers of these compounds bound rat, dog and human plasma proteins to a greater extent than did the (-)-(R)-enantiomers, except that the case of KE-298 was opposite in rat plasma. The stereoselective plasma levels of these compounds in rats, dogs, or humans would likely be due to stereoselective differences in binding to plasma albumin. The protein binding of M-1 in adjuvant-induced arthritis rat plasma was >97%, and the stereoselectivity was similar to the case of normal rat plasma. KE-298 and its metabolites remarkably displaced [14C]warfarin, which bound on albumin in a solution of diluted rat serum albumin. Similarly, there was a displacement of [14C]warfarin in solutions of dog and human serum albumin, and concomitantly the displacement of [14C]diazepam. [3H]Digitoxin was not displaced by any of the enantiomers in each albumin solution. No stereoselectivity was found in displacement by enantiomers of the three compounds. These results suggest that stereoselective protein binding can be attributed to quantitative differences in binding to albumin rather than to the different binding sites.

Animals↗
PubMed2001

Galactosyldiacylglycerol, a mammalian DNA polymerase alpha-specific inhibitor from a sea alga, Petalonia bingbamiae.

The glycolipid galactosyldiacylglycerol (GDG), containing C16:0 and C18:1 fatty acids, was isolated from the sea alga Petalonia bingbamiae as a potent inhibitor of the activities of mammalian DNA polymerase alpha (pol. alpha). GDG, however, had no effect on pol. alpha from a fish or a higher plant. The inhibition of pol. alpha by GDG was dose-dependent with an IC50 value of 54 microM. The compound did not influence the activities of other replicative DNA polymerases such as mammalian pol. delta, or repair-related enzymes such as mammalian pol. beta. GDG also did not influence the activities of prokaryotic DNA polymerases such as the Klenow fragment of DNA polymerase I, T4 DNA polymerase, Taq DNA polymerase, DNA polymerases from the higher plant, cauliflower, or DNA metabolic enzymes such as calf thymus terminal deoxynucleotidyl transferase, human immunodeficiency virus type 1 reverse transcriptase and deoxyribonuclease 1. Kinetic analysis of the compound showed that pol. alpha was non-competitively inhibited with respect to both the DNA template and the nucleotide substrate. In this study, we demonstrated the structure-function relationship in the selective inhibition of pol. alpha by the glycolipid group.

Animals↗
PubMed2001

Potential use of ultrasound in creating transmyocardial channels.

Although the mechanisms of the clinical benefits of transmyocardial laser revascularization (TMLR) are considered to be angiogenesis with increased perfusion, denervation and placebo effect, it is unknown whether laser energy is a prerequisite in obtaining these beneficial effects. The present study investigated whether it is possible to create transmyocardial channels and induce angiogenesis by ultrasound. Myocardium was penetrated with an ultrasonically activated surgical blade by advancing the blade tip perpendicularly to the left ventricular free wall of the beating heart of 6 mongrel dogs. The power of ultrasound was set at either the lowest or highest of the system. The animals were killed 30 min (acute; n=3) and 2 weeks (chronic; n=3) after channel creation. Holmium:YAG laser, which is currently used for clinical TMLR, was used to create myocardial channels in 4 other dogs, which were also killed 30 min (n=2) and 2 weeks (n=2) after channel creation. The areas of acute channel core, acute thermal damage and chronic fibrosis were compared between the laser and ultrasound channels by Masson's trichrome stain. Factor VIII and proliferating cell nuclear antigen (PCNA) immunostaining were carried out on the samples obtained from chronic animals. The density of vessels and that of proliferating vascular endothelial cells and vascular smooth muscle cells around the channels were measured. The area of acute core was larger in the lowest and highest outputs of ultrasound than in laser channels (0.78+/-0.09, 1.0+/-0.12 vs 0.38+/-0.04 mm2; p<0.01). The area of acute damage in both laser and the highest output of ultrasound channels was greater than in the channels produced by the lowest output of ultrasound (4.43+/-0.28, 4.63+/-0.44 vs 2.90+/-0.29 mm2; p<0.01). The ratio of acute damage area to acute core area was greater in laser channels than in either type of ultrasound channel (16.86+/-1.66 vs 6.04+/-0.67, 7.86+/-1.07; p<0.01) and the area of chronic fibrosis was greater (3.23+/-0.20 vs 1.59+/-0.18, 2.24+/-0.20 mm2; p<0.01). Factor VIII and PCNA immunostaining revealed new vessels not only inside the areas of chronic fibrosis, but also in the surrounding myocardium, in both laser and ultrasound channels. Ultrasound created transmyocardial channels histologically similar to laser channels and angiogenesis was induced in the normal myocardium surrounding ultrasound channels.

Animals↗
PubMed2001

Major isoforms of starch branching enzymes in premature seeds of kidney bean (Phaseolus vulgaris L.).

Developing seeds of the kidney bean (Phaseolus vulgaris L.) contain several isoforms of starch branching enzymes. Two of them, KBE1 and KBE2, which are the major forms in the premature seeds, were purified as a single band of protein on SDS-PAGE and native PAGE by chromatographies on DEAE-Sepharose, Bio-Gel P-200, and amylose-binding Sepharose 6B. The enzymes had similar pH optimum (7.0), pH stability (7.0-9.5), temperature optimum (25-30 degrees C), and temperature stability (up to 40 degrees C). Additionally, both were inhibited by various divalent metal ions and activated by citrate. Finally, though their N-terminal amino acid sequences were identical, their molecular masses and affinities for amylose differed; 80 kDa and 1.27 mM for KBE1 and 77 kDa and 0.74 mM for KBE2.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2001

Glycitein effect on suppressing the proliferation and stimulating the differentiation of osteoblastic MC3T3-E1 cells.

Glycitein, as one of the three major isoflavones in soybeans, directly but significantly (about 5%) suppressed the proliferation of MC3T3-E1 and stimulated bone-related protein (alkaline phosphatase (ALP) and osteocalcin (OC)) expression. These results indicate that glycitein suppresses the proliferation of osteoblasts and promotes differentiation from its progenitor.

3T3 Cells↗
PubMed2001

Acute cholecystitis caused by a cholesterol polyp.

A 39-year-old man hospitalized with upper abdominal pain had been found to have a 3mm polyp in the body of the gallbladder 3 years previously. Laboratory tests on admission showed mild liver dysfunction. Ultrasonography depicted a dilated gallbladder with increased wall thickness; the polyp could no longer be seen. Computed tomography with drip infusion cholangiography again showed a dilated gallbladder, and also stenosis of the distal cystic duct. The resected specimen obtained by laparoscopic cholecystectomy showed disappearance of the polyp from the body of the gallbladder. A cholesterol stone was incarcerated in the cystic duct, representing an impacted detached cholesterol polyp causing acute cholecystitis. Spontaneous detachment of a cholesterol polyp from the gallbladder mucosa, then, can result in acute cholecystitis.

Acute Disease↗
PubMed2001

Celiac artery aneurysm: a case evaluated preoperatively with three-dimensional computed tomographic angiography.

In a 63-year-old woman computed tomography (CT) incidentally detected a celiac artery aneurysm approximately 3 cm in diameter. While conventional angiography suggested that the splenic artery and common hepatic artery arose from the celiac artery aneurysm, three-dimensional CT angiography indicated that the aneurysm involved only the mid portion of the celiac artery. Considering the risk of eventual aneurysm rupture, surgery was performed. Aneurysmectomy and devascularization of hepatic, splenic, and celiac arteries were carried out following complete cross-clamping of the celiac artery. The distal segment of the celiac artery was directly anastomosed to the proximal segment in an end-to-end fashion. Histologically, the aneurysm wall showed atheromatous changes. Contrast-enhanced abdominal CT confirmed complete removal of the celiac artery aneurysm, and postoperative angiography confirmed good arterial flow. The patient recovered uneventfully after surgery, with normalization of transiently abnormal hepatic function parameters. In this case of celiac artery aneurysm, three-dimensional CT angiography was found to be valuable in determining the relationships of the aneurysms to important arterial branches.

Aneurysm↗
PubMed2001

Liver cell adenoma in a 26-year-old man.

This is a report of a case of liver cell adenoma (LCA) in a 26-year-old man with no prior history of liver disease or glycogen storage disease and no record of hormonal therapy. He was found to have an asymptomatic hepatic mass during a routine medical examination. The physical findings were unremarkable, and the results of routine laboratory studies were all within normal limits. Selective hepatic arteriography showed a hypervascular mass within the right lobe of the liver. Despite the radiological examination, the nature of the mass was unknown, and preoperative biopsy was unadvisable because of the risk of bleeding. Because of the difficulty of determining the malignancy of the hepatic tumor preoperatively, elective laparotomy for diagnosis and hepatectomy as treatment appeared to be the best available approach. Pathological examination of the surgical specimen resulted in a diagnosis of LCA. A review of the literature revealed that LCA unassociated with the use of oral contraceptives is rare.

Adenoma, Liver Cell↗
PubMed2001

Spontaneous disappearance of a hepatic cyst.

The spontaneous disappearance of a hepatic cyst is described. A 62-year-old woman presented with symptoms of general fatigue in August 1992. Her past medical history was significant for chronic hepatitis, which was diagnosed in 1990 but not treated. Initial laboratory tests revealed mild liver dysfunction with a positive serologic test for hepatitis C. In August 1992, ultrasonography and computed tomography disclosed a cystic lesion along the middle hepatic vein in the right anterior segment of the liver, which was 40 mm in diameter. Repeat radiologic studies in June 1994 demonstrated that the size of the cyst was unchanged. In May 1995, the cyst was only 25 mm in diameter, and it continued to decrease in size thereafter, to 10 mm in September 1995 and 7 mm in September 1996. No hepatic cyst was visualized in December 1996, though the region in which the cyst existed was hyperechoic. Laboratory data were essentially unchanged from August 1992 to December 1996. Clinically the patient remained asymptomatic.

Cysts↗
PubMed2001

Cilnidipine more highly attenuates cold pressor stress-induced platelet activation in hypertension than does amlodipine.

The clinical significance of N-type calcium channel blockade has not been fully examined. We here compared the effects of the N-type calcium channel blockers cilnidipine and amlodipine on the sympathetic nervous system and platelet function in hypertension under resting and stressed conditions. Thirty-two patients with hypertension (58+/-9 years) received cilnidipine or amlodipine for 4 weeks in this crossover study. On day 28 of each treatment, plasma levels of epinephrine (EP), norepinephrine (NEP), and beta-thromboglobulin (BTG), and EC50 of ADP-induced platelet aggregation (ADPE50) were determined at rest and after a cold pressor test. On day 29, the group receiving cilnidipine was switched to amlodipine treatment, and vice versa. At rest, the blood pressure, heart rates, EP, NEP, ADPEC50, and BTG, were similar in both treatments. After the cold pressor test, increases in EP (35+/-17 to 44+/-25 pg/ml; p<0.05) and BTG (40+/-13 to 49+/-22 ng/ml; p<0.01) and a decrease in ADPEC50 (32+/-26 to 27+/-24 micromol; p<0.05) were observed in the amlodipine treatment, but not in the cilnidipine treatment. In addition, the increase in NEP was significantly greater (p<0.05) in the amlodipine (276+/-78 to 318+/-87 pg/ml; p<0.01) than in the cilnidipine treatment (273+/-88 to 291+/-100 pg/ml; p<0.05). Cilnidipine more highly attenuates the activation of platelet function in response to cold pressor stress than does amlodipine. Attenuated activation of the sympathetic nervous system via N-type calcium channel blockade may contribute to this phenomenon.

Amlodipine↗
PubMed2001

Organization of cytoskeletal F-actin, G-actin, and gelsolin in the adhesion structures in cultured osteoclast.

Immunofluorescence using Gc protein (group-specific component or vitamin D binding protein [DBP]) as a marker of G-actin showed that nonfilamentous, monomeric G-actin is a component of the podosomes of osteoclasts cultured on glass plates or bone slices. Typical individual podosomes of the well-spread cells on glass plates were rosette in form. When viewed from the basolateral surface, the core portion of the dotlike podosomes was associated with packed F-actin filaments surrounded by G-actin organized in a ringlike structure. The podosomes, when viewed perpendicular to the substrate, showed a conical shape as a bundle of short F-actin core and a ring of G-actin. With cell spreading on glass plates, the clustering of the podosomes formed a continuous belt of tightly packed podosomes as an adhesion structure at the paramarginal area. In addition, these structures were seen on the ventral cell surface. Similar changes in cell shape were seen in the osteoclasts when they were plated on bone slices. With the loss of dotlike podosomes, a continuous band of F-actin was formed around the resorption lacunae. It became evident then that F- and G-actin dissociated from each other in the podosomes. The staining patterns of G-actin varied from a discrete dot to a diffuse one. Toward the nonresorption phase, the osteoclasts lost their continuous F-actin band but dotlike podosomes appeared in the leading and the trailing edges. In such a cell undergoing translational movements, G-actin was located diffusely in the cytoplasm behind the lamellipodia and along some segments of the leading edge. Cytochalasin B treatment caused cells to disorganize the actin cytoskeletal architecture, which indicated the disassembling of F-actin into G-actin in podosomes and disappearance of actin-ring of cultured osteoclasts. Staining with polyclonal actin antibody or monoclonal beta-actin was overlapped with the distribution pattern of G- and F-actin. Gelsolin was detected in the region of the adhesion area corresponding to the podosome. The observation that F-actin, G-actin, and gelsolin were detected in the osteoclastic adhesion structures suggests that the podosomes may represent sites where a rapid polymerization/depolymerization of actin occurs. These dynamic changes in cytoskeletal organization and reorganization of G-actin may reflect changes in the functional polarization of the osteoclast during the bone resorption cycle and suggest the important role of G-actin in the regulation of osteoclast adhesion.

Actins↗
PubMed2001

Management of hepatocellular carcinoma: advances in diagnosis, treatment and prevention.

Since the major causes of hepatocellular carcinoma are hepatitis viruses, the difference and similarity of clinical features in relation to the causative virus may indicate that persistent inflammation of the liver is a major role in hepatocellular carcinoma development in both HBV and HCV infection. However, there is a variety of molecular products of virus-inducing mutagenesis, especially in HBV. An advance in the diagnosis of hepatocellular carcinoma is imaging modality to detect hemodynamics of hepatocellular carcinoma with noninvasive methods of ultrasonography and tumor markers. Chemoprevention using synthetic retinoid is another important issue for the prevention of hepatocellular carcinoma development, as well as viral eradication and suppression of inflammation in the liver using interferon and other drugs.

Carcinoma, Hepatocellular↗
PubMed2001

Liquid chromatographic determination of ornithine and lysine based on intramolecular excimer-forming fluorescence derivatization.

A highly sensitive and selective fluorometric determination method for ornithine and lysine has been developed. This method is based on an intramolecular excimer-forming fluorescence derivatization with a pyrene reagent, 4-(1-pyrene)butyric acid N-hydroxysuccinimide ester (PSE), followed by reversed-phase liquid chromatography (LC). The analytes, containing two amino moieties in a molecule, were converted to the corresponding dipyrene-labeled derivatives by reaction with PSE. The derivatives afforded intramolecular excimer fluorescence (450-550 nm) which can clearly be discriminated from the normal fluorescence (370-420 nm) emitted from PSE and monopyrene-labeled derivatives of monoamines. The structures of the derivatives and the emission of excimer fluorescence were confirmed by LC with mass spectrometry and with three-dimensional fluorescence detection system, respectively. The PSE derivatives of ornithine and lysine could be separated by reversed-phase LC on ODS column with isocratic elution. The detection limits (signal-to-noise ratio = 3) for ornithine and lysine were 3.5 and 3.7 fmol, respectively, for a 20-microl injection. Furthermore, this method had enough selectivity and sensitivity for the determination of ornithine and lysine in normal human urine.

Calibration↗