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T Maeda

Publications and source records attributed to T Maeda.

At least 19 recordsLinked to original sources
PubMed1992

Butyrylcholinesterase-rich neurons in rat brain demonstrated by a sensitive histochemical method.

Butyrylcholinesterase (BChE) is a highly active enzyme in brain, but little is known about its physiological functions. One obstacle has been the lack of a sensitive and specific method for determining its cellular localization. We report here on a histochemical technique that has permitted BChE to be detected in neuronal, glial, and vascular structures. The method, which utilizes butyrylthiocholine iodide as the substrate, is a modification of our previously described method for acetylcholinesterase (AChE) histochemistry. BChE-rich neuronal somata stained much more intensely than capillaries or glia. Prominent neuronal groups were located in the anterodorsal, laterodorsal, anteroventral, reuniens, centrolateral, paratenial, and periventricular thalamic nuclei, the laterodorsal tegmental nucleus, the pedunculopontine tegmental nucleus, and the dorsal motor nucleus of vagus. Several other areas of the forebrain and brainstem showed modest numbers of positive cells. No positive cells were detected in the striatum, hippocampus, and most parts of the hypothalamus, which are regions containing numerous AChE-rich neurons. Although the distribution pattern of BChE-rich neurons differed from that of AChE-rich neurons, some neuronal groups contained both esterases. The results suggest that BChE may play a unique role in neuronal function, particularly since many BChE-rich neurons have not been identified as to neurotransmitter type.

Acetylcholinesterase↗
PubMed1992

Interference with cyclophosphamide-induced skin allograft tolerance by cyclosporin A.

In a murine strain combination identical in H-2 Ag but disparate in minor histocompatibility (H) Ag consisting of C3H/He (C3H; H-2k, Mls-1b) mice as recipients and AKR/J (AKR; H-2k, Mls-1a) mice as donors, a permanent skin allograft tolerance can be achieved by the cyclophosphamide (CP)-induced tolerance system that consists of i.v. injection of donor spleen cells (day -2) and i.p. injection of CP 2 days later (day 0). Such permanent take of allografts in CP-induced tolerant mice was interfered with by intramuscular injection of cyclosporin A (CsA) from day -5 to day -1 and their grafts were rejected by 21 days after grafting. Mls-1a-reactive CD4+V beta 6+ T cells in the periphery, as the indicator to follow the kinetics of donor-reactive T cells, increased on day 0 and day 3 in the C3H mice treated with AKR spleen cells alone, whereas they disappeared rapidly from day 0 to day 3 in CP-induced tolerant mice. When CsA capable of interfering with IL-2 production and T cell proliferation was administered before CP treatment in CP-induced tolerance system, the number of CD4+V beta 6+ T cells in periphery did not increase on day 0 and 3, but increased on day 7 in contrast to the decreased number of those in CP-induced tolerant mice. On day 7, MLR against donor cells was decreased in CP-induced tolerant mice, but maintained in CsA-interfered tolerant mice. These result may indicate that the destruction of donor-Ag-stimulated, proliferating T cells by CP is interfered with by CsA, probably because CsA inhibits the proliferation of donor-reactive T cells at the time of CP treatment. Furthermore, these results also implicate that the protocol for immunosuppression with CsA and antimetabolites has to be designed carefully in clinical transplantation.

Animals↗
PubMed1992

[A study of irradiated spines in radiotherapy--using 99mTc-HMDP bone scintigraphy & MR imaging].

When radiation therapy is performed on a patient with malignant tumor, vertebral spines are sometimes included in the irradiation field. In the present study, 99mTc-HMDP uptake was examined in 102 cases of malignant tumors treated with radiation therapy (irradiated total doses from 10 to 70 Gy) in order to clarify the time course of accumulation. The scintigram on the film was transformed with a film digitizer into objective data, and the Accumulation Decreasing Index (ADI) was calculated each month after irradiation. In the group receiving less than 30 Gy, recovery of 99mTc-HMDP accumulation was seen after a mild decrease in the ADI. However, in the group that received more than 40 Gy, no recovery of accumulation was seen, and a large decrease in the ADI followed. Vertebral MRI was performed with and without Gd-DTPA enhancement to calculate the vertebral Signal Intensity Ratio (SIR), and decreased blood flow in the irradiated bone marrow was estimated from the changes in SIR values. In the irradiated area, no definite abnormal accumulation of 99mTc-HMDP was observed against the new metastatic bone tumor. In such cases, MRI should be performed soon after bone scintigraphy in order to detect the tumor.

Bone Marrow↗
PubMed1992

[An experimental and clinical study of zonography of the lung by means of Fuji computed radiography].

Tomography was conducted for a basic study using a model of the bronchi, pulmonary arteries and veins. When the exposure angle of a tube was changed to 5, 10, 25, and 50 degrees, the width of tomograms became about 10, 4, 2, and 1 cm. When tomograms of exposure angles of 50 degrees and 10 degrees were compared, the former showed fragmentary bronchi, pulmonary arteries and veins, and the latter showed bronchi, pulmonary arteries and veins branching up, down and laterally on one image in one unit and over a wide area. Similar results were obtained in 10 cases of normal volunteer. When 25 cases of lung cancer at the hilum were studied clinically with respect to bronchial lesions, the tomograms with an exposure angle of 10 degrees could point out more lesions than the tomograms with an exposure angle of 50 degrees. In 13 cases (40 lesions) which were compared with the findings of bronchoscopy, the accuracy was only 25% in tomograms with an exposure angle of 50 degrees, and 65% in tomograms with an exposure angle of 10 degrees. These results indicate that tomograms with an exposure angle of 10 degrees are useful for analysis of the bronchi, pulmonary arteries and veins at the hilum of the lung.

Adenocarcinoma↗
PubMed1992

Transient patterns of serotonergic innervation in the rat visual cortex: normal development and effects of neonatal enucleation.

The transient aggregation of serotonin (5-HT)-containing fibers in the early development of rat visual cortex was examined immunohistochemically. The aggregation of 5-HT immunoreactive (IR) fibers consisted of three stages which were classified according to the course of time and degree of space occupied. The primary aggregation appeared in the subplate and moved upward along the development of the cortex. The aggregation proceeded to the secondary stage in presumptive layer IV. The fibers extended in a column-like structure following the secondary aggregation and formed the tertiary aggregation. The upper edge of the tertiary aggregation formed a lattice-like pattern in layer I and its structure was recognized to be similar to the structure of a 'blob' which characterizes the primary visual cortex in monkey. This transient aggregation of 5-HT-IR fibers began in the subplate of the anterior visual cortex on postnatal day 2 (PND 2) and progressed towards the posterior. On PND 11, the secondary and tertiary aggregations were completed in the entire region. No further aggregation of 5-HT-IR fibers was observed on PND 15. The anterior-to-posterior axis in the aggregation process corresponds to the direction of differentiation in the layer structure of cortex. In order to investigate the relationship between the transient aggregation of 5-HT-IR fibers and the development of the visual pathway, the secondary and tertiary aggregation on PND 11 were observed after postnatal monocular or binocular enucleation. Enucleation of eye balls did not affect either the area occupied by the 5-HT-IR fibers in the secondary aggregation or the number of column structures in the tertiary aggregation. However, the contralateral and ipsilateral cortices of monocularly enucleated cases were irregularly shaped in the secondary aggregation. The distribution of 5-HT-IR fiber terminals in the binocular area (Oc1B) increased in density on the contralateral side in the monocular enucleation, while that of both sides in the binocular enucleation was of non-homogeneous density and were shaped irregularly. The above results suggest that the transient aggregation of 5-HT-IR fibers observed in the early stage of development of visual cortex is regulated primarily by the intrinsic factors, and that extrinsic factors, such as visual pathway input, affect the aggregation within the boundary of such intrinsic factors. That is, the visual pathway input and the input balance from both eyes affect the distribution density of 5-HT-IR fibers and the shape of the visual cortex, respectively.

Animals↗
PubMed1992

Matrix assembly of recombinant fibronectin polypeptide consisting of amino-terminal 70 kDa and carboxyl-terminal 37 kDa regions.

Three different forms of recombinant human fibronectin polypeptides consisting of the amino-terminal 70 kDa region, the carboxyl-terminal 37 kDa region, or both, were expressed in mouse L cells. Although either the amino-terminal or the carboxyl-terminal region alone was only poorly incorporated into the extracellular matrix, the fused form of the polypeptide was highly capable of assembling into the matrix. These results indicate that matrix assembly of fibronectin requires both regions and can proceed in the absence of the type III repeats including the one containing the cell adhesive Arg-Gly-Asp sequence.

Animals↗
PubMed1992

T cell receptor V beta repertoire of double-negative alpha/beta T cells in patients with systemic sclerosis.

OBJECTIVE: To analyze the T cell receptor V beta gene on double-negative (DN) alpha/beta T cells, which are increased in number, on peripheral blood lymphocytes (PBL) from patients with systemic sclerosis (SSc). METHODS: The DN alpha/beta T cells were sorted by flow cytometry from PBL obtained from 3 patients with SSc. The V beta repertoire was analyzed by polymerase chain reaction. RESULTS: Only 1 or 2 V beta genes (V beta 5/7, 5, or 17) were predominantly expressed on DN alpha/beta T cells from these 3 patients. CONCLUSION: The V beta repertoire on DN alpha/beta T cells in PBL from patients with SSc is rather restricted.

Base Sequence↗
PubMed1992

Restricted junctional usage of T cell receptor V beta 2 and V beta 13 genes, which are overrepresented on infiltrating T cells in the lips of patients with Sjögren's syndrome.

OBJECTIVE: To analyze the clonality of T cell receptor (TCR) V beta 2- and V beta 13-positive T cells, which are predominantly expressed in the lips of patients with Sjögren's syndrome (SS). METHODS: The junctional sequences of complementary DNA clones encoding TCR V beta 2 and V beta 13 genes were determined by the polymerase chain reaction. Forty-one V beta 2 and 45 V beta 13 clones established from the lips of 3 SS patients were sequenced. RESULTS: The V beta 2/J beta 2.3 pair was enriched in 2 of the 3 patients (44% and 46% of the clones, respectively), and the V beta 13/J beta 2.1 sequence was dominant in 2 of the 3 (23% and 45%). These pairs were not used preferentially in peripheral blood lymphocytes from the same patients. CONCLUSION: Infiltrating V beta 2- and V beta 13-positive T cells from the lips of all 3 patients with SS were polyclonal, but the junctional usage of cells from 2 lip samples was restricted, compared with cells from peripheral blood. This suggests that not all expanded cells from the lips of SS patients are stimulated by superantigens.

Base Sequence↗
PubMed1992

QT interval shortening and ST elevation in intracoronary ECG during PTCA.

Percutaneous transluminal coronary angioplasty (PTCA) can provide a unique model of transient and reversible myocardial ischemia. The aim of this study was to assess the serial changes in QT interval during elective PTCA-induced transient ischemia. The serial changes in QT interval before, during, and after PTCA of the left anterior descending artery (LAD) were measured in patients who showed ST elevation in intracoronary electrocardiogram. Twelve consecutive patients who showed ST-segment elevation during PTCA-induced ischemia anterior precordial leads of the electrocardiogram (ECG) were enrolled in the present study. Target lesions for PTCA were all in the LAD. There were six patients with angina pectoris, two with non-Q-wave infarction, and four with Q-wave myocardial infarction. During balloon inflation, QTc interval shortened in both intracoronary ECG (ic-ECG) (0.472 +/- 0.013 vs 0.436 +/- 0.014) and surface ECG (0.462 +/- 0.012 vs 0.438 +/- 0.011). However, a significant shortening of the QT interval was more rapidly observed in the ic-ECG (20 s) than in the surface ECG (40 s). We conclude that the QT interval in both ic-ECG and surface ECG becomes shortened in PTCA-induced myocardial ischemia, and that the ic-ECG might be a good probe for detecting survived viable myocardium in the infarcted zone.

Aged↗
PubMed1992

Effects of congenital hydrocephalus on serotonergic input and barrel cytoarchitecture in the developing somatosensory cortex of rats.

The effects of progressive ventricular dilation on the development of the somatosensory cortex (SmI) were studied in congenital hydrocephalic rats, with regard to early serotonergic innervation and formation of functional cellular columns. In hydrocephalic rats, the time course, immunoreactivity, and patterns of formation and synaptogenesis of serotonin immunoreactive (5-HT-IR) terminal aggregations, which characterize the development of the SmI, were preserved. After disappearance of 5-HT-IR terminals, characteristic barrel cytoarchitecture formed normally at the site where 5-HT-IR terminal aggregations had been present. With the progression of hydrocephalus, the cerebral cortex became extremely thin and its total surface area was greatly increased, while barrels were preserved and their areas did not enlarge. These findings suggest that the basic development and the fundamental cytoarchitecture of the cortex are resistant to adverse effects of hydrocephalus.

Animals↗
PubMed1992

Ethanol stimulates apolipoprotein A-I secretion by human hepatocytes: implications for a mechanism for atherosclerosis protection.

Ethanol intake in humans has been shown to have a protective effect against coronary heart disease. The specific mechanism by which ethanol is cardioprotective has not been elucidated. Apolipoprotein (apo) A-I, the major protein of high-density lipoprotein (HDL), takes up cellular cholesterol, thus initiating reverse cholesterol transport whereby excess tissue cholesterol is eliminated. Using highly specific antibodies, we have found that ethanol increases apo A-I secretion and the incorporation of radiolabeled leucine into apo A-I by human hepatocytes (Hep-G2 cells). In addition, we have found that apo A-I molecules induced by ethanol have the ability to efflux cholesterol from human fibroblasts in vitro, and that apo A-I mass directly correlates with cholesterol efflux levels. At 10, 20, and 100 mmol/L, ethanol stimulated apo A-I secretion by 130%, 136%, and 162% of control, respectively (control, 3.71 micrograms apo A-I/micrograms DNA), also stimulating the incorporation of 3H-leucine into newly synthesized apo A-I by 115%, 131%, and 159% of control (control, 111 cpm/micrograms DNA/h). The ethanol-induced apo A-I from Hep-G2 cells (incubated with 0, 10, 20, and 100 mmol/L ethanol) effluxed 2%, 14%, 16%, and 32% label (per h/mL incubation medium), respectively. Apo A-I mass correlated linearly with cholesterol efflux (r = .99, P less than .01). This data indicates that the cardioprotective role of moderate ethanol intake in humans is mediated by its stimulatory action on hepatic apo A-I secretion, thus defining the physiological basis for increased plasma apo A-I levels in vivo.

Apolipoprotein A-I↗
PubMed1992

User and manufacturer's requirements for IMAC standardization in Japan.

Many radiologists and radiological technologists understand that Picture Archiving and Communication Systems (PACS) are useful not only for image management but also for improving the quality of patient care. However, such systems have not yet been widely installed in hospitals. In order to determine why radiologists have not installed a PACS in their hospitals, we carried out a written survey of 400 Japanese hospitals asking them to describe the current image management activities, the problems inherent in PACS and the problems related to standardization. 216 hospitals responded, and the following suggestions were compiled concerning possible improvements to PACS. (1) PACS benefit needs to be improved with respect to patient care. (2) The cost of PACS should be reduced. (3) The system should be easier to operate and should save time. (4) Standardization is needed to allow simplified, cost-effective networking. We also carried out a written survey of 25 PACS and related equipment manufacturers asking them to describe the opinions inherent in current PACs and the problems related to standardization. Ten manufacturers responded, and the various suggestions were compiled concerning possible improvements to the PAC system.

Japan↗
PubMed1992

Differing epitope selection of experimentally-induced and natural antibodies to a disease-specific autoantigen, the E2 subunit of pyruvate dehydrogenase complex (PDC-E2).

Naturally-occurring autoantibodies to a family of mitochondrial enzymes, the 2-oxoacid dehydrogenase complexes (2-OADC), characterize the human liver disease primary biliary cirrhosis. The immunodominant epitope for these autoantibodies is associated with the lipoyl-binding domain of the E2 subunit of the enzymes. The reactivity of these disease-associated autoantibodies was compared with that of antibodies raised in rats and rabbits, by immunization with various preparations derived from the 2-OADC enzymes, using immunization protocols that have successfully induced various organ-specific autoimmune diseases in animals. The immunogens included the intact pyruvate dehydrogenase complex (PDC) from bovine heart, human recombinant PDC-E2, and short synthetic peptides representing the immunodominant lipoic acid binding sequences of the 2-OADC enzymes. The techniques for antibody analysis included immunofluorescence, immunoblotting on mitochondrial extracts, ELISAs using entire PDC, PDC-E2, or synthetic peptides, epitope mapping by peptide scanning on overlapping octameric peptides representing the human PDC-E2 sequence, affinity purification on PDC-E2, and inhibition in vitro by sera of the catalytic function of PDC. Experimental immunization did not elicit any evidence of autoimmune disease. Moreover, the experimentally-induced antibodies in striking contrast to the natural autoantibodies showed preferential reactivity with PDC-E2 rather than with intact PDC, failed to inhibit in vitro the catalytic function of PDC, and, on peptide scanning, reacted with discrete epitopes, but at sites other than the lipoyl-binding region of PDC-E2. Our data indicate that 'multisystem' autoimmune diseases including primary biliary cirrhosis may not be elicitable experimentally because a critical disease-relevant autoepitope is not engaged by the immune system.

Amino Acid Sequence↗
PubMed1992

Engineering of artificial cell adhesion proteins by grafting the Arg-Gly-Asp cell adhesive signal to a calpastatin segment.

A new artificial cell adhesive protein was engineered by grafting the Arg-Gly-Asp (RGD) sequence, the minimal recognition signal of fibronectin for interaction with integrins, to a calpastatin segment by in vitro mutagenesis. The mutagenized protein showed cell adhesive activity in addition to calpain inhibitory activity. The RGD signal grafted to the calpastatin segment was recognized by the vitronectin receptor but not by the fibronectin receptor.

Amino Acid Sequence↗
PubMed1992

Characterization of a fission yeast gene, gpa2, that encodes a G alpha subunit involved in the monitoring of nutrition.

The Schizosaccharomyces pombe gpa2 gene was cloned by hybridization with a cDNA for Dictyostelium discoideum G alpha 1. It encodes a homolog of G-protein alpha-subunits with 354 amino acids and a predicted molecular mass of 40,522. Disruption of gpa2 slows cell growth but is not lethal. Cells defective in gpa2 mate and sporulate readily in the presence of plentiful nutrition, bypassing the requirement of nitrogen starvation for the initiation of sexual development. These phenotypes mimic those of cells defective in cyr1 encoding adenylyl cyclase. The level of cAMP in gpa2 null mutants is only one-third of the wild-type level. Mutations in gpa2 that are likely to inhibit the GTPase activity of the gene product cause a slight increase in intracellular cAMP levels and result in leaky sterility. The cAMP level reaches 20 times as high as the wild-type level if a cell carries both this type of gpa2 mutation and a null mutation in pde1 encoding phosphodiesterase. Cells defective in gpa2 fail to produce cAMP in response to glucose stimulation. These results suggest that Gpa2 is involved in the determination of the cAMP level according to nutritional conditions, most likely as a positive regulator of adenylyl cyclase.

Amino Acid Sequence↗
PubMed1992

Arterial blood ketone body ratio as a possible indicator for predicting fulminant hepatitis in patients with acute hepatitis.

Encephalopathy and severe coagulopathy in patients with acute hepatitis (AH) are good markers for the diagnosis of fulminant hepatitis (FH), which occurs in only about 1% of AH patients. However, even if patients show severe coagulopathy, it is quite difficult to predict FH before the onset of encephalopathy. The ratio of acetoacetate/beta-hydroxybutyrate in arterial blood (KBR) has been reported to reflect the cellular energy charge level in hepatocytes. In our previous report, KBR was quite low in FH patients and was an excellent marker for predicting the prognosis. KBR of normal subjects is distributed in a range of 1.0-2.1 (1.54 +/- 0.26, mean +/- SD). In this study, we assessed KBR serially in 15 AH patients with severe coagulopathy (hepaplastin test (HPT) < 40%), including seven patients who developed FH, to see if we could predict FH by using KBR as a marker. Seven patients with KBR < 0.6 of long duration (4 days or more) were complicated with hepatic encephalopathy (HE) and it took 3 or more days of KBR below 0.6 before HE appeared. The other eight patients with KBR < 0.6 of short duration (less than 4 days) were not complicated with HE. These data suggest that AH patients with HPT < 40% and a 3-day duration of KBR < 0.6 are at serious risk of FH.

Acute Disease↗