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Biomedical subjects

T Fukuda

Publications and source records attributed to T Fukuda.

At least 847 records · Page 47Linked to original sources
PubMed1988

Dog liver glutathione S-transferase and its strong immunoreactivity with rat transferase-P(7-7).

Dog liver cytosolic glutathione S-transferases (GSTs) were investigated to characterize their properties in comparison with rat liver transferases. Dog liver GSTs after the glutathione affinity column chromatography showed three subunit bands on SDS-polyacrylamide gel electrophoresis. These three subunits, designated as Yd1 (mol.wt 26,000), Yd2 (mol.wt 27,000) and Yd3 (mol.wt 28,000), were distinctly different from rat liver GST subunits, i.e. Ya(1) (mol.wt 26,500), Yb1(3)/Yb2(4) (mol.wt 27,500) and Yc(2) (mol.wt 28,500). Western blot analysis revealed that Yd1, Yd2 and Yd3 were immunoreacted with anti-rat GST 7-7, 1-1 and 3-3 antibodies, respectively. Four transferase activity fractions, I (pH greater than 7.63), II (pH 6.92), III (pH 5.80) and IV (pH 5.65), were obtained from affinity purified GSTs by chromatofocusing. Each fraction exhibited a characteristic substrate specificity. GST-II, III and IV were all strongly immunoreacted with anti-rat GST 7-7 antibody by immunoblotting, thus suggesting the occurrence of the heterogeneity of transferases immunologically related to rat GST subunit 7 in dog liver. Immunohistochemical examination showed that transferases immunoreacted with anti-GST 7-7 antibody have diffusely distributed throughout the lobule, while enzymes related to subunit 3 have been localized in a narrow range of cells around the central vein. These data suggest that GSTs immunologically associated with rat transferase subunit 7 may be major forms in dog liver.

Animals↗
PubMed1988

Inhibition of post-decapitation convulsions in the rat by dibenzothiepin neuroleptics via alpha 1-adrenoceptor blockade.

The mechanisms involved in inhibitory effects of isofloxythepin, a newly synthesized dibenzothiepin neuroleptic, on post-decapitation convulsions were studied in rats. Isofloxythepin (0.05-2.0 mg/kg s.c.) inhibited post-decapitation convulsions in a dose-dependent manner as shown by the decrease in the incidence and the shortening of the duration of convulsions. The convulsions were also inhibited by oxyprothepin, zotepine or chlorpromazine but not by haloperidol. Prazosin and bunazosin, both alpha 1-adrenoceptor antagonists, suppressed the post-decapitation convulsions but a non-selective alpha 2-adrenoceptor agonist, tolazoline, was without effect. The convulsions were inhibited dose dependently by clonidine, an alpha 2-adrenoceptor agonist, but were prolonged in duration by yohimbine, an alpha 2-adrenoceptor antagonist. Yohimbine antagonized the inhibitory effects of isofloxythepin, prazosin and clonidine. The noradrenaline-induced contraction of rat vas deferens was inhibited by isofloxythepin, prazosin or chlorpromazine. Isofloxythepin bound to alpha 1-receptors as did chlorpromazine in the rat brain cortex. The results imply that post-decapitation convulsions seem to be inhibited by a block of postsynaptic alpha 1-adrenoceptors, enhanced by a block of presynaptic alpha 2-adrenoceptors and reduced by isofloxythepin via the blocking of postsynaptic alpha 1-adrenoceptors. The convulsions thus could serve as a good model for studying the actions of drugs on the central nervous system alpha-adrenoceptors.

Adrenergic alpha-Agonists↗
PubMed1988

Antibodies against the human cellular 3,3',5-triiodo-L-thyronine-binding protein (p 58).

High-titer antibodies against a cellular thyroid hormone-binding protein (Mr 58,000, p58) were developed by a special immunization method. To enhance immune responses, this method uses a boosting protocol in which repeated injections of small amounts of antigen are administered at 2-day intervals. Antibodies were detected 1 week after the last injection of antigen by ELISA, Western dot blotting and immunoprecipitation. The anti-p58 antibodies recognized p58 which is bound to the thyroid hormone. With the availability of anti-p58 antibodies, it has become possible to study cellular localization and function.

Animals↗
PubMed1988

Purification and immunocytochemical detection of a protein that reveals layer V pyramidal cells in the rat cortex.

Protein 36 is a soluble protein isolated and purified from a high-speed supernatant fraction from homogenates of rat brain. To identify this protein in the brain, two-dimensional gel electrophoretograms of soluble proteins were prepared. The protein was separated by ion exchange and gel filtration chromatography. The chromatographic fractions were analyzed by two-dimensional electrophoresis. Protein 36 is a homodimer with a molecular weight of 64,000 Da and monomeric weight of 37,000 Da with an isoelectric point of 6.5. A rabbit antibody was raised to this protein. Immunocytochemical studies indicate that protein 36 is localized in large pyramidal cells, dendrites and axons of layer V of the cerebral cortex. The hippocampus contained cells in the stratum radiata and processes in the stratum pyramidalis. A variety of cell types were also observed in the globus pallidus, thalamus and hypothalamus.

Amino Acids↗
PubMed1988

Pharmacodynamics of chlorzoxazone in rats.

Pharmacological effect-time profiles of a centrally acting muscle relaxant, chlorzoxazone, were evaluated by both rotarod and crossed extensor reflex (CER) methods. Drug response was measured by percent change in the remaining time on the rod for the former method and in intensity of isometric contraction of the muscle for the latter method. The drug response was quantitated using the logarithmic-logistic function and then biophase levels were calculated. The results indicated that the maximum response was observed 10 min after drug administration for both methods at every dose studied. However, the values of ED50 indicated that the CER method was more sensitive than the other. Pharmacodynamic analysis offered the results that the dose-normalized biophase levels for each dose obtained from the CER method were coincident with each other and that the logarithmic-logistic function was proven to be of use for the pharmacodynamic modeling which could simply assess the bioavailability. On the other hand, all dose-normalized values obtained from the rotarod method did not scatter around the same line. This evidence indicated a violation of assumption for the pharmacodynamic analysis. From the above data, the CER method proved to be of use for assessing the drug response based on the dose-independent kinetics with high sensitivity.

Animals↗
PubMed1988

Histamine turnover in the brain of morphine-dependent mice.

The turnover of brain histamine was examined in mice implanted subcutaneously with a morphine pellet (50 mg free base). The numbers of naloxone-precipitated jumpings and body shakes were maximum 2 and 3 days after implantation, respectively. The brain tele-methylhistamine level significantly increased (50% to 115%) during 12 h-3 days after implantation of a morphine pellet, whereas the histamine level remained unchanged. The accumulation of tele-methylhistamine by pargyline treatment was significantly enhanced when pargyline was administered 12 h after implantation, suggesting an enhancement of histamine turnover. However, a similar degree of the tele-methylhistamine accumulation was induced by pargyline during 1-5 days after implantation, as compared with the accumulation in the control mice implanted with a placebo pellet. In mice undergoing morphine withdrawal by either the removal of morphine pellet or the treatment with naloxone 3 days after implantation, the degree of the pargyline-induced tele-methylhistamine accumulation or the (S)-alpha-fluoromethylhistidine (alpha-FMH)-induced histamine decrease was similar to that observed in the placebo pellet-control mice. The numbers of naloxone-precipitated jumpings and body shakes occurring in mice 3 days after implantation were not significantly affected by any of L-histidine, alpha-FMH or metoprine. These results suggest that turnover of histamine in the brain is enhanced by acute morphine treatment and returns to the normal rate in the stage of chronic treatment and remains unchanged during the state of withdrawal.

Animals↗
PubMed1988

MR imaging of intraspinal tumors--capability in histological differentiation and compartmentalization of extramedullary tumors.

Magnetic resonance (MR) images of 29 consecutive patients with intraspinal neoplasms (9 intramedullary tumors, 20 extramedullary tumors) were reviewed to evaluate the utility of MR imaging in distinguishing the intraspinal compartmental localisation and signal characteristics of each lesion. Compartment and histology of all neoplasms were surgically proven. MR correctly assigned one of three compartments to all lesions, 9 intramedullary, 14 intradural extramedullary (6 schwannomas, 3 neurofibromas, 5 meningiomas), and 6 extradural (3 schwannomas, 1 meningioma, 1 cavernous hemangioma, 1 metastatic renal cell carcinoma). All intramedullary tumors showed swelling of the spinal cord itself. In all five extradural tumors a low intensity band was visualized between the spinal cord and tumor. On the other hand, a low intensity band was demonstrated in no cases with intradural tumors. Visualization of this low intensity band is important in differentiating extradural from intradural-extramedullary lesions. We call this low intensity band, "the extradural sign". Signal intensity of intradural tumors varied with histology. In extramedullary tumors, signal intensity of schwannomas was similar to that of the cerebrospinal fluid (CSF) both on T1 weighted (inversion recovery) and T2 weighted spin echo (SE) images. On the other hand, meningiomas tended to be isointense to the spinal cord on both T1 and T2 weighted SE images. We found relatively reliable signal characteristics to discriminate meningioma from schwannoma.

Astrocytoma↗
PubMed1988

MR appearance of Rathke's cleft cysts.

Two of three patients who proved to have symptomatic Rathke's cleft cysts presented with visual field deficit and all with diabetes insipidus. CT showed intra- and suprasellar cystic low density lesions with ring enhancement. MR showed intra- and suprasellar masses. On the T1-weighted images two of the three had hyperintense portions similar to fat and the other a hyperintense portion similar to white matter within the cysts. These portions were isointense to brain on the T2-weighted images in all cases. This characteristic intensity on MR images provides differentiation from cystic pituitary adenomas and cystic craniopharyngiomas, and leads to correct diagnosis of Rathke's cleft cyst.

Adult↗
PubMed1988

Magnetic resonance images of tuberous sclerosis. Further observations and clinical correlations.

The cerebral lesions in tuberous sclerosis are of three kinds: subependymal nodules, cortical tubers, and cluster of heterotopic cells in the white matter. Understanding of these hamartomas is still incomplete even with modern imaging modalities. Magnetic resonance (MR) images of ten patients with tuberous sclerosis were reviewed and compared to computed tomographic (CT) scans and to the clinical severity of the disease. T2 weighted spin echo (TR = 1800, TE = 120) images and inversion recovery (TR = 2100, TI = 500-600, TE = 40) images were obtained at the same axial planes. Periventricular nodules were better seen, because of their calcifications, with CT than with MR imaging. They were demonstrated as iso- to low intensity depending on the amount of calcification on T2 weighted images, and as a similar intensity to the white matter on IR images. Small peripheral lesions in the hemispheres, which were only occasionally seen as small low density areas on CT scans, were well demonstrated on MR images. These foci were hyperintense on T2 weighted images, and hypointense on IR images. Exact location of these was not in the cortex, but in the subcortical white matter. The findings indicate that these foci represent the pathologically well known demyelinating foci, which are commonly present under the cortical tuber, but may be independent of them. Cortical tubers were not confidently identified, which suggested that they might have similar intensity to the cortical gray matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

An ultrastructural study of the invasion of Culex quinquefasciatus larvae by Leptolegnia chapmanii (Oomycetes: Saprolegniales).

Transmission electron microscopy of the invasion of Culex quinquefasciatus by Leptolegnia chapmanii confirmed that it is a primary pathogen and revealed several differences between penetration via the gut and penetration via the integument. The latter often involved aggregations of zoospores, appressoria-like swellings of the invasive hyphae, and lateral growth of hyphae between the epicutical and endocuticle. These features were not detected in the case of gut invasion, but hyphal septa at the point of entry were apparently peculiar to this route. There was no evident tissue specificity, and death presumably resulted from generalized destruction of tissues.

Animals↗
PubMed1988

Comparison of the size of neuronal and non-neuronal histamine pools in the brain of different rat strains.

The size of the neuronal and non-neuronal histamine pools in the brain of three different strains of rats was measured by assuming that the alpha-fluoromethylhistidine-induced maximal decrement of histamine represents the size of the neuronal pool. Although the total histamine levels in the brain showed a considerable interstrain variation, no significant interstrain difference was observed in the neuronal histamine level. These results suggest that the size of the neuronal histamine pool in the brain is relatively stable, whereas the size of the non-neuronal histamine pool is variable.

Animals↗
PubMed1988

Recovery from congenital complete atrioventricular block.

Congenital complete atrioventricular block without any other intracardiac anomaly reverted to sinus rhythm at the age of 7 years. The girl had had heart failure and Adams-Stokes attacks when aged 1 year, requiring pacemaker implantation. Electrocardiography confirmed sinus rhythm for the first time at the age of 7 years. At the same time, a treadmill test yielded a normal tracing without any arrhythmias.

Adams-Stokes Syndrome↗
PubMed1988

Immunological activities of multiprenylacetyl derivatives of muramyldipeptides.

The immunological properties of six kinds of multiprenylacetic acids and six kinds of multiprenylacetyl muramyldipeptide (MDP) derivatives were examined by using experimental models in mice and guinea-pigs. All the multiprenylacetyl MDP derivatives, particularly TMD-232, showed potent adjuvant activity on the circulating antibody formation against bacterial alpha-amylase in mice, and induction of delayed-type hypersensitivity to monoazobenzenearsonate N-acetyl-L-tyrosine in guinea-pigs. All multiprenylacetic acid preparations tested in this study, however, showed no adjuvant activity in these immune systems. Both TMD-17 and TMD-232 entrapped into multilamellar vesicles showed potent host stimulation activity against Sendai virus infection in mice.

Acetylmuramyl-Alanyl-Isoglutamine↗