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Biomedical subjects

T Fukuda

Publications and source records attributed to T Fukuda.

At least 739 records · Page 41Linked to original sources
PubMed1990

Postural myoclonus associated with long-term administration of neuroleptics in schizophrenic patients.

Postural myoclonus associated with long-term administration of neuroleptics was demonstrated in schizophrenic patients. Sixty patients who had been taking neuroleptics for more than 3 months were investigated for myoclonus and the relationships between postural myoclonus and age, duration of illness, duration of medication, current daily dose, cumulative dose, occurrence of abnormal finger movement, parkinsonism, and tardive dyskinesia were evaluated. Twenty-three patients (38%) showed postural myoclonus when holding the hands forward with the elbow joints flexed at about 90%. Male patients showed a higher incidence of myoclonus than female patients. Patients with myoclonus had been given significantly higher doses of neuroleptics than those without myoclonus. There was a significant correlation between the occurrence of myoclonus and abnormal finger movement. Electromyographic recordings in 7 patients with prominent myoclonus revealed that arrhythmic jerks occurred in the extensor carpi radialis and posterior deltoid muscles and that the jerks on the left and right side were not synchronized. Clonazepam reduced the frequency of the myoclonic activity.

Adult↗
PubMed1990

Hormone and DNA binding activity of a purified human thyroid hormone nuclear receptor expressed in Escherichia coli.

Using a T7 expression system, large amounts of the human placental c-erbA protein (h-TR beta 1) were expressed. From 1 liter of Escherichia coli culture, approximately 50-100 micrograms of purified h-TR beta 1 were obtained. Analysis of the binding data indicated that the purified h-TR beta 1 binds to 3,3',5-triiodo-L-thyronine (T3) with a Ka = 2.8 x 10(9) M-1. It binds to 3,3',5-triiodo-L-thyropropionic acid, 3,3',5-triiodo-L-thyroacetic acid, D-T3, L-thyroxine (T4), and 3',5',3-triiodo-L-thyronine with 475, 120, 39, 7, and 0.1%, respectively, of the activity of L-T3. This order of binding activity to T3 analogs is similar to that reported for the T3 nuclear receptor identified in tissues or cultured cells. Furthermore, the purified h-TR beta 1 binds to the T3 response element of the rat growth hormone gene. Thus, the purified h-TR beta 1 is active. To identify the hormone binding domain, the purified h-TR beta 1 was affinity labeled with underivatized [3',5'-125I]T4. A partial digestion by trypsin yielded a 125I-labeled 25-kDa fragment which was identified to be the domain Phe240-Asp456 by amino acid sequencing. Thus, the purified h-TR beta 1 appears suitable for other structural and functional studies.

Base Sequence↗
PubMed1990

Effects of zinc L-carnosine on gastric mucosal and cell damage caused by ethanol in rats. Correlation with endogenous prostaglandin E2.

The effects of zinc L-carnosine on ethanol-induced damage and the correlation of these effects with endogenous prostaglandin E2 were evaluated in rat gastric mucosa in vivo and in vitro. When given either intragastrically or intraperitoneally, zinc L-carnosine (10 or 30 mg/kg) prevented gross visible damage to gastric mucosa caused by ethanol without affecting the mucosal prostaglandin E2 level. This protective effect of zinc L-carnosine was not inhibited by indomethacin. Histological assessment showed that zinc L-carnosine inhibited deep mucosal necrosis, as did 16,16-dimethyl prostaglandin E2. Zinc L-carnosine (10(-6) or 10(-5) M) inhibited the damage caused by ethanol to gastric cells isolated from rat gastric mucosa in vitro; this effect was not inhibited by indomethacin. The results suggested that zinc L-carnosine protects the gastric mucosa and enhances cellular resistance to ethanol without the mediation of endogenous prostaglandins.

16,16-Dimethylprostaglandin E2↗
PubMed1990

Development of an eye-movement analyser possessing functions for wireless transmission and autocalibration.

An eye pointer was developed as a new line-of-sight displacement analyser. It analyses an observer's eye movements and superimposes their line of vision on a TV image which is the same as their view. A newly developed miniature colour field camera and very compact eye-movement sensors are attached to a translucent reinforced plastic goggle affording a wide view and excellent safety. A small case is provided for the eye-movement detecting circuit and the camera controller unit etc. Its weight is only 1.2 kg and one can easily participate in sports activities while wearing it. Eye-movement data are transmitted with the VHF video signal. The receiver, which analyses the eye movements and processes the TV image, is also compact and easy to carry. The calibration is automatic and completed within 1 min with a high degree of accuracy. By showing the tennis player's line of vision as an example, we were able to obtain good results with application in broadcasting programmes.

Eye Movements↗
PubMed1990

Concentration- and pH-dependent effects of local anesthetics on onset of epidural anesthesia.

This study was undertaken to determine the effect of concentration of pH-adjusted local anesthetics on the onset time of anesthesia.Lidocaine (0.9% and 1.8%) and bupivacaine (0.25% and 0.5%) were used. In the 0.9 percent lidocaine and 0.25 percent bupivacaine groups, the onset time of analgesia was shortened by about 100 and 200 seconds, when pH was adjusted to 7.4 and 7.0, respectively ( P < 0.05 and P < 0.01). In the 1.8 percent lidocaine and 0.5 percent bupivacaine groups, however, pH adjustment exerted no significant effect on the onset time. Alkalinization of low-concentration local anesthetics shortened the onset time, whereas that of high-concentration did not shorten.

Journal Article↗
PubMed1990

New electronic media and the human interface.

Discussion is focused on the relationship between the new media and the human visual system. First, the process of information transmission in the human visual system is shown as a hierarchically structured model. Second, examples of the human interface in the development of a Japanese teletext system are shown, such as desired luminance and contrast, or favourable colour combination, or how to make superimposed sentences on screen easy to read. Third, examples of the human interface in the development of Hi-Vision, or High Definition Television (HDTV), are discussed, namely the conditions required for Hi-Vision from the standpoint of visual characteristics, the visual effects of Hi-Vision, and an objective evaluation of psychological effects of Hi-Vision.

Color↗
PubMed1990

An ergonomic evaluation of lens accommodation related to visual circumstances.

This study is intended to make clear the relationships between a number of external conditions (target luminance, size, etc.), dynamic responsiveness of the lens accommodation, and microfluctuation. Further, the effects of ageing and the difference between monocular and binocular observations are examined. These studies established that age factors have a large bearing on the ability of the lens to focus on an object, as well as affecting such abilities as the responsiveness of the lens accommodation, amplitude of lens accommodation response, microfluctuation, and contraction and relaxation time. Of these accommodation functions, such factors as contraction and relaxation time clearly reflect the ease of seeing an object. Clear relationships between the amount of diopter and the ease of seeing an object were also observed. Further, it was established that a binocular observation is more responsive (velocity of contraction) than a monocular one. As to the microfluctuation, on the other hand, clear effects of age on its spectrum distribution were recognized but no definite correlations concerning the ease of seeing an object were observed.

Accommodation, Ocular↗
PubMed1990

Dose-response relationship of ozone-induced airway hyperresponsiveness in unanesthetized guinea pigs.

The effect of ozone dose (the product of ozone concentration and exposure time) on airway responsiveness was examined in unanesthetized, spontaneously breathing guinea pigs. Airway responsiveness was assessed by measuring specific airway resistance (sRaw) as a function of increasing concentration of inhaled methacholine (Mch) aerosol (the concentration of Mch required in order to double the baseline sRaw: PC200Mch). The airway responsiveness was measured before and at 5 min, 5 h, and 24 h after exposure. A 30-min exposure to 1 ppm ozone (dose 30 ppm.min) did not change PC200Mch at any time after exposure. Both a 90-min exposure to 1 ppm ozone and a 30-min exposure to 3 ppm ozone, which are identical in terms of ozone dose (90 ppm.min), decreased PC200Mch to a similar degree. A 120-min exposure to 3 ppm ozone (360 ppm.min) produced a much greater decrease of PC200Mch at 5 min and 5 h after exposure, compared with low-dose exposure. There was a significant correlation between ozone dose and the change in airway responsiveness. In all groups, the baseline sRaw was increased by approximately 50% at 5 min after exposure, but there was no correlation between the changes in PC200Mch and the baseline sRaw. This study suggests that ozone-induced airway hyperresponsiveness in guinea pigs is closely related to ozone dose.

Aerosols↗
PubMed1990

Large-scale purification of bovine brain lactate dehydrogenase by affinity chromatography on immobilized colchicine.

Lactate dehydrogenase (LDH) [EC 1.1.1.27] in a crude extract (40-80% ammonium sulfate fraction) of bovine brain was adsorbed on an immobilized colchicine column and specifically eluted by addition of 1 mM NADH. The purity and subunit composition of the pooled LDH were estimated by two-dimensional gel electrophoresis. With an increase of NaCl concentration from 0 to 2.0 M, ligand saturation of LDH on immobilized colchicine increased from 6.8 to 14%, whereas that on immobilized Cibacron blue F3GA decreased from 2.1 to 0%. In the presence of high NaCl concentration, immobilized colchicine enabled both large- and small-scale purification of LDH by affinity chromatography and resulted in a yield of 117 mg from 1 kg of bovine brain in the presence of 2.5 M NaCl or higher recoveries of 54-96% from various tissues of one rat in the presence of 1.0 M NaCl. These results indicate that immobilized colchicine is an excellent adsorbent for the isolation and purification of LDH by affinity chromatography and has a high LDH-adsorbing capacity dependent upon a high NaCl concentration. Kinetic studies revealed that colchicine apparently competed with cofactor NAD for the active site of LDH and the Ki values of colchicine decreased with an increase of NaCl concentration. The chemical specificity of the colchicine-binding site of LDH was studied by the use of colchicine analogues and it is concluded that both the tropolone moiety (C-ring) and the amido bond in a side chain of colchicine structure are essential to the colchicine-LDH interaction.

Animals↗
PubMed1990

Protein kinase C-dependent phosphorylation of sarcolemmal Ca2(+)-ATPase isolated from bovine aortic smooth muscle.

We examined the effect of protein kinase C (PKC)-dependent phosphorylation on Ca2+ uptake and ATP hydrolysis by microsomal as well as purified sarcolemmal Ca2(+)-ATPase preparations isolated from bovine aortic smooth muscle. The phosphorylation was performed by treating these preparations with PKC and saturating concentrations of ATP (or ATP-gamma S), Ca2+, and 12-O-tetradecanoyl phorbol-13-acetate (TPA) at 37 degrees C for 10 min. In microsomes, treatment with PKC enhanced a portion of the Ca2+ uptake activity inhibitable by 10 microM vanadate, by up to about 30%. On the other hand, Ca2(+)-dependent ATPase activity in the purified Ca2(+)-ATPase preparation was stimulated by up to twofold. Up to twofold stimulation by PKC was also observed for the Ca2+ uptake by proteoliposomes reconstituted from purified sarcolemmal Ca2(+)-ATPase and phospholipids. Since these effects were evident only at Ca2+ concentrations between 0.1 to 1.0 microM, we concluded that it was the affinity of the Ca2(+)-ATPase for Ca2+ that was increased by the PKC treatment. Under conditions in which PKC increased Ca2+ pump activity, the sarcolemmal Ca2(+)-ATPase was phosphorylated to a level of about 1 mol per mol of the enzyme. There was good parallelism between the ATPase phosphorylation and the extent of enzyme activation. These results strongly suggest that the activity of the sarcolemmal Ca2+ pump in vascular smooth muscle is regulated through its direct phosphorylation by PKC.

Adenosine Triphosphate↗
PubMed1990

In vitro adaptive cytoprotection in gastric cells isolated from rat stomach.

The effects of mild irritants (2-5% ethanol or water at 45-55 degrees C) on production of prostaglandins (PGs) in gastric cells isolated from rat stomach and the damage caused by 15% ethanol were assessed. Gastric cells were isolated by the method of Matuoka et al., by which a suspension rich in surface epithelial cells was obtained. Synthesis of PGE2 by the cells was stimulated by 3% ethanol or water at 50 degrees C. The damage caused by 15% ethanol was much less in the cells treated with 3% ethanol or 50 degrees C water beforehand than in untreated cells. This protective effect by 3% ethanol or 50 degrees C water was abolished when the cells were treated with 10(-4) M indomethacin. These results suggest that 3% ethanol or 50 degrees C water protects the gastric cells from damage caused by 15% ethanol, possibly via endogenous PGs.

Animals↗
PubMed1990

Possible role of leukotrienes in gastritis associated with Campylobacter pylori.

This study was done to evaluate the role of leukotrienes (LTs) in gastritis associated with Campylobacter pylori. Biopsy specimens of gastric mucosa were obtained endoscopically from 18 patients with nonulcer dyspepsia for bacteriological and histological examination and extraction of LTs. There was correlation between the LTB4 level in the mucosa and the degree of gastritis evaluated histologically. The level was higher when infiltration of neutrophils in the gastric mucosa was more extensive. The LTB4 level in mucosa infected with C. pylori was higher than that in noninfected mucosa. These findings suggest that endogenous LTs may be related to the pathogenesis of gastritis associated with C. pylori.

Adult↗
PubMed1990

Swollen cortical neurons in Creutzfeldt-Jakob disease contain a phosphorylated neurofilament epitope.

The distribution of swollen neurons and the presence of a phosphorylated neurofilament protein (NFP) epitope in these cells were studied in six cases of Creutzfeldt-Jakob disease (CJD). Swollen neurons are widely distributed in the cerebral cortex and are most abundant in the cingulate and parahippocampal gyri. They are more numerous in the panencephalopathic type of CJD than in the subacute spongiform encephalopathic type. A phosphorylated epitope of NFP was detected in the perikarya of swollen neurons by an immunocytochemical method using a series of monoclonal antibodies that distinguish phosphorylated and nonphosphorylated epitopes of NFP. This abnormal distribution of phosphorylated NFP epitopes indicates that the process of NFP phosphorylation is altered in neurons affected by CJD. This investigation, in accordance with previous studies, suggests that the abnormal post-translational modification of the neurofilament may play an important role in the pathogenesis of several neurodegenerative disorders.

Antibodies, Monoclonal↗
PubMed1990

Cytokine regulation of HLA on thyroid epithelial cells.

The regulation of class I and class II HLA expression in human thyroid follicular cells was studied in vitro. Tumour necrosis factor-alpha (TNF-alpha) enhanced the expression of class I antigen on thyrocytes, but these cytokines had little effect on the expression of class II antigen. Interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) did not affect class I and class II antigen expression. The combination of interferon-gamma (IFN-gamma) with TNF-alpha or IL-1 beta enhanced the induction of class I and class II antigens, compared with the effect of IFN-gamma alone. Neither class I nor class II expression was induced by IL-6 alone or in combination with IFN-gamma. These findings suggest that TNF-alpha and IL-1 beta may have an important role in inappropriate expression of HLA antigens on thyrocytes in thyroid gland.

Cell Survival↗
PubMed1990

A side reaction in solid phase synthesis. Insertion of glycine residues into peptide chains via Nim----N alpha transfer.

In solid-phase peptide synthesis using N alpha-Boc-Nim-tosyl-histidine (Boc-His(Tos)), byproducts having extra Gly residues in the peptide chain were observed at a high rate. When a Boc-amino acid such as Asn was incorporated after assembly of Boc-His(Tos), the Nim-tosyl group was partially or fully cleaved by an activating agent, 1-hydroxybenzotriazole. In the successive coupling reactions, Boc-Gly was incorporated into the free Nim ring as well as the alpha-amino function, and the Nim-Gly was then transferred to the alpha-amino group of Gly of the peptide chain after removal of these Boc groups to give extra Gly residues at the position of Gly. This was observed in only the coupling reaction with Boc-Gly and could be circumvented using a more stable Nim protecting group for His, such as a dinitrophenyl group.

Amino Acid Sequence↗
PubMed1990

Effects of intravenous administration of local anesthetics on the renal sympathetic nerve activity during nitrous oxide and nitrous oxide-halothane anesthesia in the cat.

The effects of subseizure doses of lidocaine and bupivacaine administered intravenously (i.v.) on mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were studied in cats anesthetized with nitrous oxide (N2O)-O2 and N2O-O2-halothane (1%). In cats anesthetized with N2O-O2, MAP decreased briefly (P less than 0.01) and then returned to the initial level within a minute after the i.v. injection of lidocaine (5 mg/kg, 10 mg/kg). RSNA increased at first and then decreased slightly. In cats with denervated baroreceptors, the change in RSNA after lidocaine 5 mg/kg i.v. was similar to that in cats with intact baroreceptors. In contrast, MAP, HR and RSNA decreased significantly (P less than 0.01) after i.v. injection of lidocaine during N2O-O2-halothane anesthesia. The effects of bupivacaine on RSNA were similar to those of lidocaine. It is concluded that cardiovascular depression following intravenous local anesthetics during N2O-O2-halothane anesthesia may be caused by both a decreased sympathetic activity and a direct depressant effect on the myocardium.

Anesthesia, Inhalation↗