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Biomedical subjects

Y Inada

Publications and source records attributed to Y Inada.

At least 73 records · Page 4Linked to original sources
PubMed1989

In vivo binding of circulating immune complexes by C3b receptors (CR1) of transfused erythrocytes.

The effects of packed erythrocyte transfusion with high CR1 activity on circulating immune complex concentrations were studied in 14 transfusion experiments involving 12 patients with immune complex related diseases. Before erythrocyte transfusion circulating immune complex concentrations ranged from 8 to 128 micrograms/ml. After transfusion (2-3 units) immune complex concentrations decreased depending on the levels of CH50 titres in the recipients. In 11 experiments, in which the patients' CH50 titres ranged from 21 to 44, immune complex concentrations decreased by 75-100% within five days. The CH50 titres were also decreased after erythrocyte transfusion but subsequently increased to initial ranges within 6-35 days. In three patients with low CH50 titres (1.0-10.0) decreases in immune complexes were not observed. Direct Coombs' tests for IgG and C3 were performed before and after erythrocyte transfusion to determine potential in vivo binding of circulating immune complexes. Thus in eight of 14 experiments, in which erythrocytes carried no IgG before packed erythrocyte transfusion, seven became Coombs' positive for IgG after the transfusion. In seven of 14 experiments, in which erythrocytes were negative for complement before transfusion, five became positive afterwards. Moreover, in 12 instances slight increases of CR1 activity of patients' erythrocytes were observed within eight days, which improved further within 35 days after erythrocyte transfusion. These studies suggest that transfusion of erythrocytes with high CR1 activity results in the removal of circulating immune complexes and that this process is dependent on complement consumption. These experiments support the hypothesis that erythrocyte-CR1 has a functional role in the removal of circulating immune complexes and may thereby inhibit the deposition of immune complexes within body tissue constituents.

Antigen-Antibody Complex↗
PubMed1989

[Histopathological and clinical studies of acute necrotizing ulcerative gingivitis and evaluation of treatment].

We report the clinical data, light and electron microscopic findings, therapy and clinical course of three cases treated for acute necrotizing ulcerative gingivitis. The following results were obtained. 1. An ulcerous lesion was observed in the gingiva of all three cases, with case I also showing a depressed lesion in the ulcerous region. 2. In all three cases, the gingival sections displayed ulceration and showed fibrin deposition and neutrophil infiltration on the surface of the ulcerous region. Congested blood vessels and neutrophil infiltration also were observed in the connective tissue beneath the ulcerous region. 3. Many microorganisms, fibrin, cell debris, and enlarged intercellular spaces of the epithelium were seen on the surface on the ulcerous region. 4. Localized treatment, mainly plaque control, was found to be effective clinically and histopathologically.

Gingivitis, Necrotizing Ulcerative↗
PubMed1989

[Comparison of effects on carbohydrate metabolism of hypotension induced by sodium nitroprusside and a nitroprusside-trimetaphan mixture in rabbits].

Effects on carbohydrate metabolism of hypotension induced by sodium nitroprusside and a nitroprusside-trimetaphan mixture were studied in 29 male rabbits under halothane anesthesia. They were randomly divided into three groups; Nitroprusside (Group N; n = 10), A Nitroprusside-Trimetaphan Mixture (Group M; n = 10), Control (Group C; n = 9). No changes were noted in blood glucose, blood lactate, blood pyruvate and lactate/pyruvate ratio in Group C throughout the experiment. During induced hypotension, blood glucose, blood lactate, blood pyruvate and L/P ratio of group N were significantly higher than the control value. On the other hand, in group M, blood glucose and blood pyruvate tended to increase slightly but not significantly. In contrast, in group M, L/P ratio remained unchanged. The results suggest that sodium nitroprusside tended to cause tissue hypoxia more markedly than a nitroprusside-trimetaphan mixture. The mechanism may be that a mixture of nitroprusside and trimetaphan maintained the carbohydrate metabolism (including gluconeogenesis, glucogenolysis) during induced hypotension. In conclusion, our results suggest that a nitroprusside-trimetaphan mixture is a safe method for hypotensive anesthesia.

Animals↗
PubMed1989

Esterification of chiral secondary alcohols with fatty acid in organic solvents by polyethylene glycol-modified lipase.

Lipase from Pseudomonas fragi 22.39B was modified with polyethylene glycol. The modified lipase (PEG-lipase) was soluble and active in organic solvents such as benzene and 1,1,1-trichloroethane. PEG-lipase catalyzed esterification of chiral secondary alcohols with fatty acids in benzene and exhibited preference for R isomers over S isomers. Km and Vmax values for each isomer of various alcohols were obtained by kinetic study of the esterification in benzene. PEG-lipase-catalyzed esterification leads to optical resolution of a racemic alcohol.

Alcohols↗
PubMed1989

[Comparison of endocrine effects of hypotension induced by sodium nitroprusside, trimetaphan camsylate and a nitroprusside-trimetaphan mixture in rabbits].

Endocrine effects of hypotension induced by nitroprusside, trimetaphan and a nitroprusside-trimetaphan mixture were studied in 34 male rabbits under halothane anesthesia. They were randomly divided into four groups; nitroprusside (group N; n = 8), trimetaphan (group T; n = 10), a nitroprusside-trimetaphan mixture (group M; n = 8) and controls (group C; n = 8). No change was noted in plasma catecholamines measured in group C throughout the experiment, but plasma renin activity decreased progressively. During induced hypotension, plasma catecholamines and plasma renin activity of group N were significantly higher than the control value. In contrast, in group T plasma epinephrine decreased significantly. On the other hand, in group M, plasma renin activity showed a slight but not significant increase, while plasma catecholamines remained unchanged. This may have occurred since a mixture of nitroprusside and trimetaphan produced the dissociation of renin-angiotensin-sympathoadrenal loop. In conclusion, these results suggest that a nitroprusside-trimetaphan mixture is a useful method for hypotensive anesthesia by inhibiting the excessive activation of renin-angiotensin-sympathetic system.

Animals↗
PubMed1989

[The clinical application of ultra-low field (0.02 T) MRI for the diagnosis of lung tumors].

Seventy-one patients with lung tumors were studied by thoracic Ultra-low field MRI (L-MRI) and the efficacy of L-MRI is evaluated as compared with the dynamic CT scan. In staging of lung cancer, L-MRI is not useful because of its poor spatial resolution. Both T1 (Inversion recovery) and T2 (long SE) weighted images can differentiate secondary atelectasis from central tumors in 15 out of 18 (78%). This sensitivity is almost equal as that of dynamic CT. IR images with short inversion time (STIR) are particularly useful for their differentiation.

Adult↗
PubMed1988

Subunit B of factor XIII is present in bovine platelets.

Distribution of B subunit of coagulation factor XIII(FXIII B) in bovine platelets was determined. Intracellular location of FXIII B in platelets was confirmed by fluorescent antibody technique. Positive staining of FXIII B was observed with Triton-permeabilized platelets but not with non-permeabilized platelets. Immunoblots of plasma and platelet lysate revealed that the antibody was specific for FXIII B and this antigen existed in the supernatant of sonication-solubilized platelets. The amount of FXIII B in platelets was determined to be 17.3 +/- 6.7 ng/10(8) platelets by radioimmunoassay. This is the first visual and quantitative demonstration of intracellular FXIII B.

Animals↗
PubMed1988

Plasma albumin is essential for collagen-induced platelet aggregation.

We found that platelets must have albumin on the surface to respond to collagen and aggregate. Albumin, however, was not absolutely necessary for ADP-, platelet activating factor-, serotonin- or thrombin-induced aggregation, while fibrinogen was required for ADP- or serotonin-induced aggregation. Immunofluorescent microscopy revealed that albumin was retained on gel-filtrated platelets but not on washed platelets. Albumin was not required for platelet adhesion to immobilized collagen. Without albumin thromboxane formation upon collagen-stimulation was diminished. These data suggest that albumin is essential in some step(s) that results in production of thromboxane A2.

Animals↗
PubMed1988

Magnetic urokinase: targeting of urokinase to fibrin clot.

A plasminogen activator of human origin, urokinase, was endowed with magnetic property. The magnetic urokinase was composed of magnetite, polyethylene glycol derivative and urokinase, and dispersed in saline. Its particle size of magnetite was approximately 30-60 nm. It was selectively delivered to fibrin clot by magnetic force in continuously circulating plasma and exerted fibrinolytic activity without degrading fibrinogen.

Blood Coagulation Tests↗
PubMed1988

"A" subunit of factor XIII is present on bovine platelet membrane and mediates collagen-induced platelet activation.

The Fab fragment of a polyclonal antibody against platelet factor XIII inhibited the collagen-induced platelet aggregation in a dose-dependent manner. This inhibitory effect was specific for collagen, and it had no effect on arachidonic acid-, ADP-, and serotonin-induced aggregations. This finding strengthens our notion that platelet factor XIII is involved in collagen-induced platelet aggregation. (Saito, Y., Imada, T., Takagi, J., Kikuchi, T. and Inada, Y. J. Biol. Chem. 261, 1355-1358, 1986). We have investigated membrane localization of bovine platelet factor XIII using immunological techniques. Immunofluorescent visualization revealed that the factor XIII was expressed on the surface of non-permeabilized bovine platelets, where we detected neither lactate dehydrogenase, a cytoplasmic enzyme marker, nor B subunit of factor XIII, which is present in plasma. Cell surface iodination and immunoprecipitation also confirmed that it existed on the surface of platelets.

Animals↗
PubMed1988

Venom from southern copperhead snake (Agkistrodon contortrix contortrix). II. A unique phospholipase A2 that induces platelet aggregation.

A platelet aggregation factor was purified from the venom of southern copperhead snake (Agkistrodon contortrix contortrix) by DEAE-cellulose ion-exchange chromatography, precipitation with ammonium sulfate, affinity chromatography using bovine serum albumin as ligand, and gel filtration on Cellulofine GCL-2000. It had molecular weights of 11,000 and 14,000, as determined by gel filtration chromatography and sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS-PAGE), respectively. It consists of a single polypeptide, and was identified as a phospholipase A2. It was quite resistant to heat and various denaturing reagents including urea and SDS. It lost both phospholipase A2 activity and platelet aggregating activity upon modification of histidine residue(s) with p-bromophenacyl bromide. Its specificity towards the beta-position of phospholipid in esterolytic reaction was confirmed by gas-liquid chromatography using a pure synthetic phosphatidylcholine. Platelet aggregation by this phospholipase A2 was completely inhibited by prostacyclin, but was little inhibited by aspirin which indicates almost no direct participation of released arachidonic acid in the aggregation mechanism.

Animals↗
PubMed1988

Skin graft including subcutaneous vein: experimental study and clinical applications.

Skin grafting, using full and split thickness techniques, may yield poor results when satisfactory circulation is not restored in the recipient bed. Using a rabbit ear model with a vein located in the center of the graft, donor skin and subcutaneous vein were raised simultaneously, and the vein was preserved, resulting in a viable passage for inflow and outflow. Grafts were shown to survive in this experimental group when circulation was satisfactory after venous preservation. In the control group with no vein preservation, all grafts became necrotic. These results were clinically applied for cases in which skin defects, caused by finger trauma, resulted in poor circulation in the recipient bed. Skin and subcutaneous vein were simultaneously taken from the forearm and grafted successfully, resulting in excellent prognoses.

Adult↗
PubMed1988

(R)-3-[(S)-1-carboxy-5-(4-piperidyl)pentyl]amino-4-oxo-2,3,4,5- tetrahydro-1,5-benzothiazepine-5-acetic acid (CV-5975): a new potent and long-lasting inhibitor of angiotensin converting enzyme.

The synthetic design and the biological activities of structurally new angiotensin converting enzyme (ACE) inhibitors, (R)-3-amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetic acid derivatives, are described. A number of compounds in this series showed potent ACE inhibitory activity in vitro and in vivo. Structure-activity studies indicated that a piperidyl moiety on the amino group at the 3-position in this series conferred long-lasting ACE inhibitory activity and that the duration of activity depended on the length of the carbon chain in the 1-carboxy-omega-(4-piperidyl)alkyl group. (R)-3-[(S)-1-carboxy-5-(4-piperidyl)-pentyl]amino-4-oxo-2,3,4,5-tetrahydro- 1,5-benzothiazepine-5-acetic acid (CV-5975) was selected as the most promising ACE inhibitor for further studies because of its marked inhibitory activity.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Antihypertensive action of a new angiotensin converting enzyme inhibitor, (R)-3-[(S)-1-carboxy-5-(4-piperidyl)pentyl]amino-4-oxo-2,3,4,5-tetr ahy dro-1,5-benzothiazepine-5-acetic acid (CV-5975), in various hypertensive models.

The antihypertensive activity of a new angiotensin converting enzyme (ACE) inhibitor, CV-5975, (R)-3-[(S)-1-carboxy-5-(4-piperidyl)pentyl] amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetic acid, was examined in normotensive rats and various hypertensive animal models. In spontaneously hypertensive rats, CV-5975 (1 to 10 mg/kg, p.o.) had a dose-related, sustained antihypertensive action, which was more potent and longer than that of enalapril. The potency and duration of action of CV-5975 was intensified when it was administered repeatedly or combined with hydrochlorothiazide. CV-5975 (1 mg/kg, p.o.) inhibited the ACE activity of plasma and tissues; inhibition on the ACE activity of the aorta, kidney, and brain was marked when CV-5975 was administered repeatedly. In 2-kidney, 1 clip hypertensive rats (1 to 10 mg/kg, p.o.) and dogs (0.3 and 1 mg/kg, p.o.), CV-5975 had a marked, sustained antihypertensive action, which was more marked than that of enalapril. In normotensive rats (10 mg/kg), 1-kidney, 1 clip hypertensive rats (3 and 10 mg/kg), and hyporeninemic DOCA/salt hypertensive rats (1 to 10 mg/kg/day), CV-5975 administered orally once or repeatedly reduced blood pressure, whereas enalapril did not. These results indicate that CV-5975 is a potent and long-lasting antihypertensive agent, the action of which is mediated primarily by inhibiting ACE activity and partly by some unknown mechanisms.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1988

Inhibition of angiotensin converting enzyme by (R)-3-[(S)-1-carboxy-5-(4-piperidyl)pentyl]amino-4-oxo-2,3,4,5-tetra- hydro-1,5-benzothiazepine-6-acetic acid (CV-5975), a non-sulfhydryl compound.

CV-5975, (R)-3-[(S)-1-carboxy-5-(4-piperidyl)pentyl]amino-4-oxo- 2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetic acid, was found to inhibit rabbit lung angiotensin converting enzyme (ACE) activity with an IC50 of 3.1 x 10(-9) M and a Ki of 2.6 x 10(-9) M, inhibit the angiotensin I (A-I)-induced contraction of the guinea pig ileum with an IC50 of 1.3 x 10(-8) M, and augment the bradykinin (BK)-induced contraction of the ileum with an AC50 of 9.2 x 10(-10) M. The activity of CV-5975 was comparable to or slightly more potent than that of enalaprilat. The overall inhibition constant (Ki*), calculated from a steady-state analysis of enzyme reactions, was 4.4 x 10(-12) M for CV-5975; this indicates that the inhibition was about 5 times more potent than that of enalaprilat (2.0 x 10(-11) M). In rats, CV-5975 (0.03 and 0.3 mg/kg, i.v. and 3 and 10 mg/kg, p.o.) inhibited the A-I-induced pressor action more potently and for a longer period than did the corresponding doses of enalaprilat and enalapril. CV-5975 and enalapril (3 mg/kg, p.o.) augmented the BK-induced depressor action to a similar extent. In dogs, CV-5975 (0.3 and 1 mg/kg, p.o.) markedly inhibited the A-I-induced pressor action in a dose related manner, and the duration of this inhibitory activity was longer than with the corresponding doses of enalapril. These data provide evidence for the proposal that CV-5975 is a highly potent and long lasting ACE inhibitor.

Angiotensin I↗
PubMed1988

[A study of ultrasonic scaler. The effect of the different frequencies of the ultrasonics in the experimental calculus removal and roughness of the metallic plate after scaling].

In an attempt to determine how the degree of the experimental calculus removal on the metallic plate and its roughness after scaling would be affected by ultrasonics under high or low frequency, quantitative measurement and morphological observation were made. The results obtained were as follows: 1. On the calculus removal, larger effect was obtained by high frequency unit than low frequency. 2. On the roughness of the metallic plate after scaling, larger defect was observed by high frequency unit than low frequency. 3. Scanning electron microscopically, strip like defects were observed under low frequency unit, while exfoliation of the metallic plate in addition to the strip like defects were observed under high frequency.

Dental Calculus↗