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Biomedical subjects

Y Gotoh

Publications and source records attributed to Y Gotoh.

At least 199 records · Page 11Linked to original sources
PubMed1990

[Free and conjugated catecholamines in gastric and bile juice during surgical operations].

From 40 patients under surgical operation, gastric or bile juice was obtained to determine the possible excretion of free and conjugated catecholamine (CA) into the two kinds of juice. The patients were divided into normal renal function group and chronic renal failure group and former group was further divided into the dopamine (DA)-administered group and the non-DA-administered group. In the non-DA group with normal renal function, the gastric juice contained 0.30 +/- 0.11ng.ml-1 of free and 0.12 +/- 0.06ng.ml-1 of conjugated norepinephrine (NE) and also 0.09 +/- 0.07ng.ml-1 of free and 0.40 +/- 0.10ng.ml-1 of conjugated DA. In DA group, the gastric juice contained 2.01 +/- 0.41ng.ml-1 of free and 3.66 +/- 0.84ng.ml-1 of conjugated DA respectively. Significant differences in DA were observed between two groups. In the bile juice, the conjugated NE increased significantly from 0.15 +/- 0.05 ng.ml-1 to 1.24 +/- 0.34ng.ml-1 and also the conjugated DA increased significantly from 2.17 +/- 0.77ng.ml-1 to 21.33 +/- 5.23ng.ml-1 by infusion of DA at the rate of 2 micrograms.kg-1.min-1 for 197 +/- 48min. In chronic renal failure group, the conjugated NE and DA increased significantly to 1.04 +/- 0.27ng.ml-1 and 1.64 +/- 0.61ng.ml-1 respectively compared to that of normal renal group. It was confirmed that gastric juice and bile juice contain the free and conjugated CA during surgical operation and by the infusion of DA, free and conjugated DA are excreted into gastric juice and bile juice and also conjugated CA in the gastric juice from chronic renal failure group is increased.

Adult↗
PubMed1990

[Relief of intractable post-herpetic neuralgia with gasserian ganglion block using methyl prednisolone acetate and with TENS].

A 58 year old man had been suffering from intractable left ophthalmic post herpetic neuralgia (PHN) for 7 years. He has also been treated for polyarteritis nodosa for 10 years. For pain relief, he was treated initially with frequent (4 times a day) stellate ganglion block (SGB) and peripheral ophthalmic nerve block for a month without relief. Then supraorbital nerve block with neurolytics, TENS and acupuncture were done with a slight relief of his pain. Recently his pain became worse even with imipramine 75 mg and carbamazepine 100 mg a day which relieved effectively the patient from the pain for the last 3 years. The pain was so severe to disturb his usual daily activity. Gasserian ganglion block with methyl prednisolone acetate 10 mg was done. After the block, his ADL improved markedly. Three months after the block, he had no spontaneous pain and slight pain with light touch on the injured skin did not annoy him. Several days before the block, electric stimulation to control his pain was tested. Stimulation with the electricity (4.5 mA, 10 cycle and 400 microseconds) brought him complete relief from the pain during the stimulation. Trigeminal SEP showed no response to the stimulation of injured skin.

Anti-Inflammatory Agents↗
PubMed1990

[Treatment of chronic retinal artery obstruction with stellate ganglion block and electric acupuncture].

A 56-year-old man (160 cm, 64 kg) having right visual field defect due to obstruction of the central retinal artery for 6 months was treated with stellate ganglion block and electric acupuncture. His visual field improved slightly immediately after preliminary treatment with stellate ganglion block and electric acupuncture judging from perimeter recording and his complaints. Stellate ganglion block on every day and electric acupuncture on every other day were performed for 10 days and there after these treatments were done two times a week. Twenty days after starting the treatment, his visual field improved on his perimeter examination. We discussed that the cause of improvement was activation of slept cone cells which needed more energy for activation than rod cells by increasing retinal blood flow with stellate ganglion block and electric acupuncture. We recommend vasodilating treatments such as stellate ganglion block and electric acupuncture for visual field defect due to obstruction of central retinal artery even in chronic state.

Acupuncture Therapy↗
PubMed1990

[An analysis of ictal EEGs by a newly developed ambulatory cassette EEG system].

We evaluated the efficiency of a newly developed cassette EEG recording device and our system for detecting and analyzing ictal EEGs in epileptic children. We got 13 ictal records from 16 epileptic children. We could precisely differentiate and diagnose their classifications of seizures by comparative analyses of ictal records and clinical symptoms. We discussed the characteristics of our system, and described actual analysis methods in 3 cases as examples. It was concluded that our system offered valuable information about ictal events in epileptic children.

Adolescent↗
PubMed1989

Specific lesions of rat spinal interneurons induced by systemic administration of acromelic acid, a new potent kainate analogue.

A single systemic injection of acromelic acid, a potent kainate analogue, caused behavioral and pathological effects distinct from those seen after systemic kainate. There was an initial marked tonic extension of the rat hindlimb, followed often by convulsions and, in surviving rats, by a transient flaccid paralysis and, ultimately, a persistent spastic paraplegia. Pathological examination suggested specific lesions of interneurons in the lower spinal cord with little or no damage to the hippocampal neurons preferentially affected by systemic kainate.

Animals↗
PubMed1989

Mineralization induced by beta-glycerophosphate in cultures leads to a marked increase in collagenase synthesis by mouse osteogenic MC3T3-E1 cells under subsequent stimulation with heparin.

The clonally derived mouse osteoblast-like cell line MC3T3-E1 was shown to produce latent collagenase (approximately 0.2 units/ml) under stimulation with either heparin or parathyroid hormone in confluent cultures. However, it was found that MC3T3 E1 cultures which were first induced to undergo mineralization by the addition of beta-glycerophosphate and were subsequently stimulated with heparin showed an approximately ten-fold increase in collagenase synthesis. MC3T3-E1 cell collagenase from a small sample of serum-free culture medium was purified 49-fold to a specific activity of 200 units/mg protein with a yield of 14% by heparin-sepharose affinity chromatography and ion-exchange high performance liquid chromatography. This new mineralization-primed cell culture system may be a valuable model for the study of osteoblast collagenase.

Alkaline Phosphatase↗
PubMed1989

Purification and characterization of 20-hydroxy-leukotriene B4 dehydrogenase in human neutrophils.

Leukotriene B4 (LTB4) is converted to 20-hydroxy-LTB4 (20-OH-LTB4) which is subsequently oxidized to 20-carboxy-LTB4 (20-COOH-LTB4). The oxidation of the hydroxy LTB4 to the carboxy LTB4 by human neutrophils was associated with the reduction of NAD+ and required both cytosolic and microsomal fractions. We isolated a cytosolic protein which oxidized the hydroxy LTB4 in the presence of NAD+ and the microsomal fraction. It was homogeneous on SDS/PAGE, with a subunit molecular mass of 37 kDa, and may be a dimeric protein with two identical or similar subunits because its molecular mass, estimated by Sephadex G-100 column chromatography, was about 80 kDa. The protein was an alcohol dehydrogenase with high affinity for omega-hydroxy fatty acids, such as 12-hydroxylaurate and 16-hydroxypalmitate. We conclude that the cytosolic protein oxidizes 20-OH-LTB4 to 20-oxo-LTB4 and the microsomal fraction oxidizes the oxo-LTB4 to the carboxy-LTB4, based on the finding that the activity which oxidizes omega-hydroxy fatty acids is present only in the cytosol fraction, while that which oxidizes hydrophobic aldehydes is found only in the microsomal fraction and that the stoichiometry of the formation of 20-COOH-LTB4 to the reduction of NAD+ was 1:2. The affinity of the dehydrogenase for 20-OH-LTB4 may be higher than that for 12-hydroxylaurate (Km = 70 microM), because the latter inhibited the oxidation of the former by only 40%, at a concentration of 12-hydroxylaurate 10 times higher than that of 20-OH-LTB4. The enzyme activity was not affected by pyrazole and 4-methylpyrazole at millimolar concentrations. These characteristics indicate that the dehydrogenase is a unique type of alcohol dehydrogenase.

Alcohol Oxidoreductases↗
PubMed1989

Further purification of a fibroblast growth factor-like factor from chick embryo extract by heparin-affinity chromatography.

A mitogenic factor which promotes quail myoblast proliferation has been purified some 10(5)-fold from chick embryo extract by a combination of cation-exchange chromatography and heparin-affinity chromatography. The factor is eluted from heparin-Sepharose with 2 M NaCl and is a single-chain polypeptide with an apparent molecular weight of 15,000 to 17,000. It is active at subnanogram level in triggering the proliferation and thereby delaying temporarily fusion of myoblasts. It also stimulates the proliferation of quail fibroblasts in a similar effective concentration range. For both myoblasts and fibroblasts the dose-response to the factor is quantitatively and qualitatively comparable with that of bovine pituitary fibroblast growth factor. These observations strongly suggest that the factor very probably corresponds to chicken fibroblast growth factor or to a closely related molecule(s) and that it is possibly involved in the regulation of myogenesis.

Animals↗
PubMed1989

Comparison of the effects of amrinone and dobutamine on hemodynamics and myocardial oxygen balance in dogs with experimental left ventricular failure.

The purpose of the present study was to induce left ventricular failure in anesthetized dogs by repeated ventricular fibrillation and then to determine if amrinone is effective in circulatory support by comparing the effects of amrinone and dobutamine. After the repetitive ventricular fibrillation, mean arterial pressure and stroke volume index decreased, pulmonary capillary wedge pressure (PCWP) increased, and acute left ventricular failure occurred. Thereafter, dogs were divided into the following four groups. In Group C (n = 6), normal saline was administered; in Group D (n = 6), dobutamine was administered at 7 micrograms/kg/min; and in Groups A40 (n = 6) and A80 (n = 7), amrinone was administered at 40 micrograms/kg/min and 80 micrograms/kg/min, respectively. Stroke volume index increased by 78% in Group D and 46% in both Groups A40 and A80. Pulmonary capillary wedge pressure decreased by 44% in Group A40 and 38% in Group A80, but remained unchanged in Group D. Similarly, total peripheral resistance decreased by 32% in Group A40, 29% in Group A80, but remained unchanged in Group D. These results suggest that amrinone increased cardiac output and decreased both preload and afterload. In the coronary circulation, both drugs caused direct coronary vasodilation since they increased myocardial oxygen supply in excess of the increase in myocardial oxygen demand. Neither drug produced signs of myocardial ischemia, as indicated by myocardial lactate metabolism. Amrinone should be a useful drug after open heart surgery, especially in cases where significant adverse effects of catecholamines occur or where a low-output state with increased preload and afterload exists.

Amrinone↗
PubMed1989

Characterization of copper atoms in bilirubin oxidase by spectroscopic analyses.

Bilirubin oxidase [EC 1.3.3.5], purified from the culture medium of Myrothecium verrucaria, was found to contain two blue copper atoms per protein molecule with a molecular weight of ca. 52 kDa. The two copper atoms were estimated to be in the all cupric state by the cuproine colorimetric method and also atomic absorption analysis. We could remove the reduce cuprous ions from the holo enzyme by adding ascorbate, followed by a KCN solution, yielding an apo-enzyme with no activity. The apo-enzyme can be reconstituted with Cu or other divalent cations such as Co, Fe, and Cd, with accompanying recovery of the enzyme activity. The activity recovery depended upon the species of cation employed; Cu being most effective, an almost 100% recovery, and Cd the least, only a 25% recovery. We could obtain information on the copper ions and their coordination structure by spectroscopic analyses of the apo- and reconstituted enzymes, obtaining such as absorption, CD, MCD, and XPS spectra. The bilirubin oxidase catalyzed-reaction was a second order reaction with respect to copper bound with protein. The donor set was of the CuSS*N2 (S = Cys, S* = Met, N = His) type, i.e., the same as in the case of blue copper proteins. On studying the Co-substituted enzyme, it was revealed that the copper site of the enzyme had a 4-coordinated structure.

Apoproteins↗
PubMed1989

Slow onset of and recovery from Ca blocking action of benidipine in rat aorta and portal vein.

Effects of benidipine, a newly developed 1,4-dihydropyridine derivative, on the high K+-induced contraction in aorta and the spontaneous contraction in portal vein of the rat were examined. When either tissue was treated with a low concentration (0.1-10 nM) of benidipine for 90, 180 min or a longer period, the evoked or spontaneous contraction was reduced in a time- and concentration-dependent manner. The time required for 50% inhibition by 1 nM benidipine was approximately 60 and 120 min in the portal vein and aorta, respectively. Although the exact IC50 of benidipine was not determined because of the unexpectedly slow onset of the effect, it might have been overestimated previously and is apparently lower than 1 nM. After the withdrawal of 1 nM benidipine, its inhibitory action was not removed significantly even by washing for 5 hr. A partial or full recovery from the inhibition was observed in tissues pretreated with 0.3 nM benidipine. The persistent inhibition after withdrawal of 1 nM benidipine was not removed by Bay K 8644 treatment. The results strongly suggest that the slow recovery from the benidipine-induced inhibition is, at least in part, responsible for the long-lasting antihypertensive effects of benidipine.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1989

Ultrastructural immunolocalization of a major phosphoprotein in embryonic chick bone.

Immunocytochemistry utilizing the protein A-gold technique was used to examine the ultrastructural cellular and extracellular distribution of a major phosphoprotein in chick bone. HCl-extracts of embryonic and neo-natal chick bones contain a major 66kD phosphoprotein (BPP) which was purified and used to raise polyclonal antibodies in rabbits. The mid-diaphyseal regions of 8-, 12- and 18-day embryonic chick tibiae were fixed with 1% glutaraldehyde and embedded in Epon or Lowicryl. Electron microscopy following incubation of tissue sections with the antibody and the protein A-gold complex revealed specific immunolabeling over the rER and Golgi apparatus of osteoblasts and over those areas of bone matrix containing Ca and P as determined by electron probe x-ray microanalysis. These included extracellular areas in the matrix undergoing early mineralization and electron dense patches occurring at the mineralization front and extending throughout the more mature bone regions. Biochemical analyses of bone tissue processed similarly to that used for immunocytochemistry confirmed the retention of phosphoprotein in the tissue. The spatial correlation of phosphoprotein in the extracellular matrix with Ca-P mineral deposits confirms an earlier report using 33Pi and radioautography and may indicate a role for phosphoproteins in calcification.

Animals↗
PubMed1989

Use of cultured embryonic chicken osteoblasts as a model of cellular differentiation and bone mineralization.

When chicken embryonic progenitor cells were selected and grown in culture as previously described, by 30 days cellular differentiation could be demonstrated by expression of in vivo levels of osteocalcin, alkaline phosphatase (APase), type I collagen and phosphoproteins (PP). Ultrastructural analysis revealed that the cultures were similar morphologically to young osteoid in vivo with structural features including well-developed, orthogonally arranged collagen fibrils with 64-70 nm periodicity and electron opaque areas consisting of very poorly crystalline hydroxyapatite. Analysis of collagen synthesis versus collagen accumulation in the matrix indicated a temporal inconsistency between the time of synthesis and accumulation, suggesting that accumulation was largely controlled at the level of fibril formation. Analysis of PP accumulation demonstrated a 10-fold increase in total phosphoamino acid content over the 30 day time course. PP synthesis analyzed by [3H]-Ser(P) and [14C]-Thr(P) incorporation showed an induction similar to that seen for APase. Experiments undertaken to characterize the nature of PP synthesized by the cultures identified a unique 66 kD protein. This protein was purified from chick tibial and calvarial bone and a polyclonal antibody was raised in rabbits. Ultrastructural immunocytochemistry using this antibody and the protein A-gold technique revealed specific immunolabelling over regions of mineralizing matrix in vitro, a reaction identical to that observed for the distribution of this 66 kD PP in vivo during embryonic tibial bone development in the chicken.

Animals↗
PubMed1989

[Effect of combined administration of HBs antigen and anti-HBs antibody on induction of anti-HBs antibody production in vitro and in vivo].

It was considered that nonresponsiveness to hepatitis B surface antigen was in part due to a failure in the antigen recognition (i.e., antigens' phagocytosis, processing and presentation by accessory cells). In order to enhance the capture of antigens, we investigated the effect of simultaneous administration of HBs antigen and anti-HBs IgG on antibody responses in vitro and in vivo. As a result, in vitro sensitization of mononuclear cells from anti-HBs-positive subjects with HBs antigen and anti-HBs IgG induced significant amounts of anti-HBs IgG production in 5 of 6 cases, whereas sensitization with HBs antigen alone failed to induce the antibody production in most cases. In vivo administration of HBs vaccine and anti-HBs immunoglobulin to non-responders to the vaccine triggered active anti-HBs antibody responses in 3 of 7 cases in vivo and in 5 of 7 cases in vitro.

Hepatitis B Antibodies↗
PubMed1989

[Anesthetic management of a patient with acromegaly complicated with hyperthyroidism].

A rare anesthetic experience of a 30-year-old woman with acromegaly complicated with Basedow's disease is reported. After the thyroid function was successfully controlled by drug therapy, resection of pituitary adenoma was performed under general anesthesia. Anesthesia was induced and maintained with NLA. No problem was observed during the operation and postoperative period. Careful attention should be paid to the management of circulation, respiration, metabolism and endocrinium through the perioperative period.

Acromegaly↗
PubMed1989

Effects of halothane and enflurane on conduction velocity and maximum rate of rise of action potential upstroke in guinea pig papillary muscles.

Using standard microelectrode techniques, the effects of halothane and enflurane on the maximum rate of rise of action potential upstroke (Vmax) and conduction velocity of excitation were compared with those of fast sodium channel blockers in isolated guinea pig papillary muscles. Lidocaine and tetrodotoxin decreased the square of the conduction velocity in proportion to the decrease in Vmax. In contrast, halothane and enflurane only slightly affected Vmax, but decreased the conduction velocity in a concentration-dependent manner. These results suggest that these volatile anesthetics affect conduction velocity by a mechanism different from that of fast sodium channel blockers. Caution should be used when these anesthetics are administered to patients receiving class 1 antiarrhythmic agents or who have pre-existing intraventricular conduction disease.

Action Potentials↗
PubMed1988

NAD+-dependent oxidation of 20-hydroxyleukotriene B4 to 20-carboxyleukotriene B4 by rat liver cytosol.

20-Hydroxyleukotriene B4 was converted by rat liver homogenates in the presence of NAD+ to a more polar product on reverse-phase high-performance liquid chromatography. The product was identified as 20-carboxyleukotriene B4 by straight-phase high performance liquid chromatography, ultraviolet spectrophotometry and gas chromatography-mass spectrometry. The oxidative activity of the homogenates was located in the cytosol with an optimal pH of 8.0. The activity was dependent on NAD+, and NADP+ could not substitute for NAD+. 1 mol of 20-carboxyleukotriene B4 was formed with the reduction of 2 mol of NAD+. The reaction was inhibited by pyrazole and 4-methylpyrazole, inhibitors of alcohol dehydrogenase, and by various alcohols, such as ethanol, 12-hydroxylaurate, and 20-hydroxyprostaglandin E1. Disulfiram, an inhibitor of aldehyde dehydrogenase, also inhibited the activity. These results suggest that two discrete steps catalyzed by different enzymes, alcohol dehydrogenase and aldehyde dehydrogenase, are involved in the oxidation of 20-hydroxyleukotriene B4 in rat liver cytosol. The enzyme system seems to be different from that of human neutrophils.

Animals↗