Biomedical subjects
Publications and source records attributed to Y Mine.
Fourteen year old female visited our hospital suffering from anterior chest pain. Chest CT revealed anterior mediastinal mass which had multiple cystic lesions, 8.5 x 7.0 x 5.5 cm in size. Tumor extirpation had performed by median sternotomy and pathological diagnosis was mature teratoma. CA 19-9 and CEA in the cystic fluid had elevated 32,790 U/ml and 768 ng/ml, respectively.
Chemical modification of ovomucoid third domain (DIII) has been conducted to characterize the binding site residues that determine antigenecity and allergenecity of DIII. Nitration of Tyr, ethoxyformylation of His and succinylation of Lys residues led to a decrease of alpha-helix content of DIII. Modification of His, Tyr, Glu, Asp and Lys residues on DIII resulted in a reduction of human IgG binding activity, but little effect on IgE binding activity. These results suggest that hydrophilic residues appear to be more critical for human IgG binding site, whereas hydrophobic residues may be more important for IgG binding site.
Microbubble-based contrast agents can enhance echoes in areas of low blood flow, but the bubbles are extremely sensitive and collapse easily when exposed to ultrasound (US) irradiation. An experimental study of bubble collapse was carried out to design new functions for US diagnostic systems to detect echoes from microbubbles more efficiently. For contrast agent (Levovist) solution, a high-intensity, but momentary, echo (flash echo), was observed in the first frame image after a several-second suspension of transmission, but was not seen in the second frame image. These "flash echo" signals were analyzed and categorized based on microscopic observation, and the results showed that the longevity of the microbubbles was reduced by conditions such as B-mode imaging. Next, a numerical simulation of the bubbles in liquid was performed under the same conditions as in the in vitro experiment. The results showed that even bubbles less than 1 microm in diameter expand and collapse within one pulse drive, which would generate flash echoes. The flash echo imaging system described here permits flexible intermittent scanning with variable intervals, with a variable number of frames at the trigger, and with simultaneous monitoring at low power output. Animal experiments were also conducted to evaluate the system. As the interval between frames was increased, the flash echoes gradually increased, and perfusion in the parenchyma was clearly observed with an interval of 4 s.
The aim of this study was to evaluate in vivo kinetics of microbubbles of SH U 508 A, in comparison with Indocyanine Green, a dye used as an indicator of blood flow. Microbubble kinetics were evaluated in various vessels (i.e., vena cava, aorta, renal artery, renal vein and portal vein) in rabbits after injection of SH U 508 A by measuring Doppler signals (n = 5). The kinetics of Indocyanine Green were evaluated by measuring absorbance using a photodiode (n = 5). Test substances (SH U 508 A 300 mg/mL and Indocyanine Green 1.25 mg/mL) were injected IV at a dose of 0.1 mL/kg B.W. Peak signal intensity was observed immediately after injection of SH U 508 A, followed by biphasic decay. The rates of biphasic decay were similar in all vessels. A second peak of the signal, which indicated recirculation of the microbubbles, was observed in the vena cava. The circulation and recirculation times of the microbubbles after injection of SH U 508 A were similar to that of Indocyanine Green. These findings suggest that the majority of SH U 508 A microbubbles circulate through the body similarly to blood flow, without retention, in the vasculature.
To investigate the importance of linear and conformational structure and carbohydrate chains in hen ovomucoid epitopes, the IgG and IgE binding activities of three native and reduced carboxymethylated (RCM) domains (DI, DII, and DIII) were compared using human sera from egg-white-allergic patients. There was significantly more IgG and IgE binding activity to DIII than to DI and DII. The IgG binding activity to RCM domains was similar to the native form, while RCM-DIII had significantly greater binding activity to IgE antibody (p < 0.05). It indicated that the main IgE and IgG epitopes on each domain were of linear structure. However, the total reactivity of the three domains was estimated to be about 50-60% (IgG binding) and 55-75% (IgE binding) compared with total reactivity in ovomucoid, resulting in some ovomucoid epitopes consisting of conformational epitopes on domain I-II or II-III. The carbohydrate moieties in DIII had a rather inhibiting effect on its IgG and IgE binding activities.
We evaluated the relationship between the onset of DNA damage and the characteristics of 5 model chemical mutagens with the single-cell gel electrophoresis (SCG) assay using L5178Y mouse lymphoma cells. We treated the cells with each chemical for 3 h and sampled them 0.21, and 45 h after treatment. DNA damage induced by UV mimetic mutagens MMS and MNU, and X-ray mimetic mutagen BLM was observed just after treatment, crosslinking agent MMC-induced DNA damage was detected 21 h after treatment, and 6-MP as an inhibitor of DNA synthesis did not induce DNA damage at any sampling time. These results suggest that the SCG assay detects DNA lesions just after treatment with UV and X-ray mimetic mutagens, but needs a waiting period after treatment with crosslinking agents.
Adsorption behavior of egg yolk low-density lipoprotein (LDL) constituents in oil-in-water emulsions (20% triolein) was examined. The mean particle size was decreased with increase in LDL concentrations and reached a plateau at 60 mg/mL of LDL concentrations. The average particle size and concentration of lipoproteins at the interface were greater for emulsions made at pH 3.0 and 5.0 than at pH 7.0 and 9.0, resulting from the formation of lipoprotein dimers at acid pHs. Electrophoretic analysis revealed that the three polypeptides (64, 43, and 19 kDa) in LDL constituents did not adsorb at the interface, independent of the LDL concentration, pHs, and NaCl content. On the other hand, cholesterol in LDL was preferentially adsorbed to the interfaces at the low LDL concentration. The ratio of phosphatidylcholine and phosphatidylethanolamine was increased with increased of LDL concentration. These results suggest that egg yolk LDL micelles breakdown when the micelles come into contact with the interface and rearrangement of lipoproteins, cholesterol, and phospholipids take place following adsorption at an O/W interface.
We examined the binding affinity of mosapride citrate (mosapride) (4-amino-5-chloro-2-ethoxy-N-[[4-(4-fluorobenzyl)-2-morpholinyl]me thyl] benzamide citrate), a novel gastroprokinetic agent, for the 5-hydroxytryptamine (5-HT) 4 receptors in guinea pig ileum using a selective 5-HT4-receptor radioligand, [3H]GR113808. In membrane preparations from longitudinal muscle with myenteric plexus in guinea pig ileum, specific [3H]GR113808 binding revealed a single saturable site of high affinity (Kd=0.28 +/-0.02 nM, Bmax = 45+/- 3 fmol/mg protein). Mosapride and other 5-HT4-receptor agonists inhibited the specific binding of [3H]GR113808 in guinea pig ileum. The 5-HT4 agonists examined displayed the following inhibition potency order: BIMU-8 > cisapride > mosapride > renzapride > 5-HT > zacopride > metoclopramide. Mosapride exhibited monophasic inhibition of the specific [3H]GR113808 binding in the ileum (Ki value: 84.2 nM). The presence of mosapride (30 nM) significantly increased the Kd value to 0.44+/-0.05 nM in the Scatchard analysis of [3H]GR113808 binding. Bmax of [3H]GR113808, however, was not affected (48 +/-4 fmol/mg protein) by mosapride. As for the affinity of mosapride, the addition of GppNHp (100microM) slightly increased the Ki value to 104 nM. These results indicate that mosapride has an affinity for 5-HT4 receptors in guinea pig ileum in the radioligand binding study.
The complete amino acid sequence of gladiolus bulb chitinase-a (GBC-a) was determined. First the tryptic peptides from GBC-a after it was reduced and S-carboxymethylated were sequenced and then the peptides were further studied by chemical cleavage of the enzyme. GBC-a consisted of 274 amino acid residues and had a molecular mass of 30,714 Da. Two consensus sequences essential for chitinase activity by plant class III chitinases were conserved in GBC-a, although its sequence similarity with plant class III chitinases was less than 20%. Sequence comparison of GBC-a with sequences of other proteins in a protein identification resource (PIR) showed that the GBC-a sequence was 33% similar to that of narbonin, a seed storage 2S globulin from narbon beans.
Microbubbles undergoing resonant oscillation in a diagnostic ultrasound field can be induced to exhibit nonlinear motion. The ultrasound signals emitted by such microbubbles contain strong harmonics at twice the frequency of the transmitted ultrasound beam. Second harmonic imaging improves tissue-agent contrast. The usefulness of second harmonic imaging was evaluated in vivo experiments. The hepatic parenchyma was clearly enhanced in dogs. Second harmonic imaging can be expected to expand the capabilities of diagnostic ultrasound systems in visualizing tissue perfusion.
We evaluated the relationship between the onset of DNA damage and the characteristics of 5 model chemical mutagens with the single-cell gel electrophoresis (SCG) assay using L5178Y mouse lymphoma cells. We treated the cells with each chemical for 3 h and sampled them 0, 21, and 45 h after treatment. DNA damage induced by UV mimetic mutagens MMS and MNU, and X-ray mimetic mutagen BLM was observed just after treatment, crosslinking agent MMC-induced DNA damage was detected 21 h after treatment, and 6-MP as an inhibitor of DNA synthesis did not induce DNA damage at any sampling time. These results suggest that the SCG assay detects DNA lesions just after treatment with UV and X-ray mimetic mutagens, but needs a waiting period after treatment with crosslinking agents.
RATIONALE AND OBJECTIVES: The authors evaluate the efficacy of SHU 508A, a galactose-based contrast agent used in gray-scale second harmonic imaging in vitro and in vivo experiments. METHODS: A Toshiba prototype harmonic imaging system (2.5/5.0 MHz) was used with SHU 508A in a phantom experiment and to image the liver in five healthy rabbits and one rabbit that had VX-2 tumors in the liver. RESULTS: In the second harmonic imaging, most of the fundamental components of the backscattered echo were eliminated, and good images with high contrast were obtained in the phantom experiment. Liver parenchyma was enhanced clearly in all rabbits at 0.3 mL/kg, an effect that lasted for 90 seconds. The tumor, which was mostly necrotic, was depicted clearly as a negative enhanced area surrounded by enhanced healthy liver. CONCLUSIONS: Gray-scale second harmonic imaging is a promising new method for visualization of perfusion of organs.
Two chitinase isoforms, designated GBC-a and GBC-b, were purified from the bulbs of gladiolus (Gladiolus gandavensis) using CM-cellulose column chromatography followed by Butyl-Toyopearl 650 M hydrophobic column chromatography, gel filtration on Sephadex G-75, and Mono-S FPLC. GBC-a and GBC-b are weakly acidic and weakly basic proteins with molecular masses of 30 kDa, and isoelectric points of 6.0 and 7.5, respectively. GBC-a and GBC-b were found to be homologous proteins with similar amino acid compositions and N-terminal sequences. The number of half-cystine residues in GBC-a and GBC-b was only one each, which is much lower than those of plant class I (15-17 Cys residues/mol), class II (5-8 Cys residues/mol), and class III (6 Cys residues/mol) chitinases. The N-terminal sequences of GBC-a and GBC-b were completely different from those of plant three classes of chitinases. The optimal pHs of these chitinases toward glycolchitin were pH 5. GBC-a hydrolyzed (GlcNAc)5 into (GlcNAc)2, (GlcNAc)3 and (GlcNAc)4, and (GlcNAc)5 into (GlcNAc)2 and (GlcNAc)3.
Mosapride citrate is a new gastroprokinetic agent that enhances the upper GI motility by stimulating 5-hydroxytryptamine4 (5-HT4) receptors. The purpose of this study was to compare the effects of mosapride and the existing 5-HT4 receptor agonists on GI motility in conscious dogs and on various 5-HT4 receptor-mediated responses in vitro. In conscious dogs with force transducers implanted, mosapride (0.3-3 mg/kg i.v.) stimulated the antral motility without affecting the colonic motility. However, cisapride, zacopride and BIMU 8 (0. 1-1 mg/kg i.v.) stimulated both antral and colonic motility. The enhanced GI motility induced by mosapride or cisapride was antagonized by pretreatment with GR113808 (1 mg/kg bolus i.v., thereafter 1 mg/kg/hr infusion), a selective 5-HT4 receptor antagonist. In the receptor binding studies, mosapride inhibited [3H]-GR113808 binding to 5-HT4 receptor sites of guinea pig striatum with an IC50 value of 113 nM. In addition, mosapride caused relaxation of the carbachol-precontracted rat esophagus, enhanced the electrically evoked contractions of guinea pig ileum and evoked the contractions of guinea pig distal colon with EC50 values of 208, 73, and 3029 nM, respectively; this indicates that mosapride has a low affinity for colon than for the rest of the GI tract. In contrast, cisapride, zacopride or BIMU 8 had similar potencies in all preparations examined. In conclusion, these studies indicate that mosapride selectively stimulates upper GI motility in vivo and in vitro. These results also suggest heterogeneity of 5-HT4 receptors in the GI tract.
Prograf (FK506) was given to male mature rats in a daily subcutaneous dose of 1 or 3 mg/kg/day for 2 weeks to investigate its effect on spermatogenesis. Prograf dose-dependently sperm counts and motility, but did not affect testosterone level in the serum of rats. Histopathologically, there were no abnormal changes in the testis, seminal vesicle or prostate in any rats dosed with Prograf, but intra-ductal eosinophilic globules, probably degeneration of the sperm cells, were observed in the epididymis of the 3 mg/kg/day group. Sperm counts and motility returned to the control levels after stopping of the drug. The results indicate that Prograf decreased sperm counts and motility through direct action on the sperm in the epididymis, but not the production of sperm in the testis. Cyclosporine A (CsA) was used as the reference drug in the present study. Thirty mg/kg/day of CsA also decreased sperm counts and motility, and stopping of the drug led to the recovery of these changes. The males dosed with Prograf for 2 weeks were mated with non-dosed females to investigate its effect on the fertility potential of the males. Prograf did not affect copulation or fertility index, but a decrease in the number of live fetuses associated with implantation loss was observed in the 3 mg/kg/day group. The changes were considered to be due to the decrease of sperm counts and motility, although 1 mg/kg/day of Prograf, 5-10 times the clinical dose, did not affect any fertility parameters including implantation index.
The effects of cisplatin on erythropoietin (EPO) production were investigated in comparison with the effects of phenylhydrazine in rats. Cisplatin (4.5 mg/kg i.p. bolus) decreased red blood cell count (RBC), hematocrit (Hct) and hemoglobin concentration (Hgb) for 14 days after dosing. These decreases were accompanied with increases of blood urea nitrogen (BUN) and serum creatinine (s-CRE). Both serum EPO concentration and kidney EPO mRNA content were significantly decreased in cisplatin-treated rats. On the other hand, phenylhydrazine (10 mg/kg p.o. once a day for 8 days) decreased RBC, Hct and Hgb, and increased serum EPO concentration and kidney EPO mRNA content. Phenylhydrazine had little effect on BUN or s-CRE. These results suggest that a suppression of EPO production is involved in the pathophysiology of cisplatin-induced renal anemia and that measurement of serum EPO concentration and kidney EPO mRNA content is available for distinguishing renal anemia from hemolytic anemia.
FK 453 ((+)-(R)-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl) acryloyl]-2-piperidine ethanol, CAS 121524-18-3) is a potent non-xanthine adenosine A1 receptor antagonist with diuretic and renal vasodilatory activity. The general pharmacology of FK 453 was investigated in mice, rats, guinea-pigs and dogs. In in vivo tests, FK 453 had little effect on the central nervous system (general behaviour, spontaneous motor activity, potentiation of barbiturate anesthesia, anticonvulsant activity, analgesic activity and body temperature), hematological system (bleeding time, coagulation time and recalcification time) and intestinal charcoal transit. FK 453 also did not show any cardiovascular (blood pressure, heart rate and femoral blood flow) or respiratory effects. In in vitro tests, although FK 453 had little effect on noradrenaline-induced contraction in rat vas deferens and histamine-induced contraction in guinea-pig trachea, FK 453 inhibited the acetylcholine-, histamine- and barium-induced contraction in isolated guinea-pig ileum and serotonin-induced contraction in isolated rat stomach. FK 453 also exerted significant inhibitory activity on collagen- and U 46619-induced platelet aggregation. However these effects of FK 453 on isolated tissue and platelet were observed only at high concentrations. These results suggest that FK 453 possesses a selective pharmacological profile, and one promising therapeutic site for this drug is in the kidney.
OBJECTIVES: The aim of this study was to examine the accuracy and validity of a newly developed tissue Doppler imaging system in in vitro and in vivo studies. BACKGROUND: Because quantitative measurement of wall motion velocity in real time is still difficult by conventional echocardiography, we developed a new system for evaluating ventricular wall motion by analyzing Doppler signals from cardiac tissue. METHODS: We used a modified Doppler color imaging system, omitting the high pass filter to allow Doppler signals from cardiac tissue to enter the auto-correlator. Ultrasound carrier and pulse repetition frequencies were 3.75 MHz and 3.0 to 6.0 kHz, respectively. Under these conditions, the lowest measurable velocity was 0.2 cm/s. RESULTS: In the rotating sponge model, the measured velocity correlated well with the actual velocity (y = 0.97x + 2.17, r = 0.99). In clinical settings, the mid-ejection mean velocity at either endocardial or epicardial sites of the left ventricular posterior wall measured by M-mode tissue Doppler imaging correlated well with that measured by conventional M-mode echocardiography (y = 0.94x + 0.64, r = 0.99). During systole, in healthy subjects, the anterior left ventricular wall was color-coded blue and the posterior wall was color-coded red, whereas the akinetic regions associated with myocardial infarction showed no color throughout the cardiac cycle. The ventricular posterior wall excursion velocity, defined as the difference between velocities at the endocardial and epicardial sites, was significantly slower in patients with dilated cardiomyopathy (0.4 +/- 0.3 cm/s) than in normal subjects (2.0 +/- 0.6 cm/s). CONCLUSIONS: These results indicate that the present system accurately represents tissue velocity and can create two-dimensional color images that facilitate visual assessment of ventricular wall motion.