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Biomedical subjects

T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 451 records · Page 25Linked to original sources
PubMed1997

[Repair of D-transposition of the great arteries associated with double aortic arch].

We report a case of D-transposition of the great arteries associated with double aortic arch. An aortic root angiogram revealed that the left-sided aortic arch was anterior and smaller than the right one and the descending thoracic aorta located on the left side of the spine. Balloon atrial septostomy was performed at one day of age. The patient underwent a simultaneous arterial switch procedure and division of the vascular ring at the isthmus of the left aortic arch through a median sternotomy incision at the age of 16 days. There was persistent postoperative difficulty in weaning the patient from the ventilator. Magnetic resonance images showed re-formation of pseudovascular ring by the connective tissue grown around the divided arch. At the age of 23 days, resection of the remnant of left aortic arch including the left subclavian artery and the diverticulum concomitant with vascular suspension procedure was performed through a left lateral thoracotomy. The patient was subsequently extubated without difficulty and was discharged from the hospital. It is though that a vascular suspension procedure and resection of the subclavian artery are necessary to avoid respiratory obstruction when the great arteries are in an anteroposterior position and Lecompte procedure is performed.

Aorta, Thoracic↗
PubMed1997

[A successful Konno's operation for subaortic stenosis progressed after total correction of partial atrioventricular septal defect associated with polysplenia].

Konno's operation was successfully performed on a small infant, weighing 3.8 kg. She underwent pulmonary artery banding on the 29th day of life under the diagnosis of partial atrioventricular septal defect with a small left ventricle, associated with polysplenia. Intracardiac repair was subsequently performed on the 45th day of life, which included atrial partition and mitral valvuloplasty. Eleven months after the second operation, wedge resection on the narrow subaortic fibrous lesion was done concomitant with mitral revalvuloplasty. However, repeated echocardiac study disclosed progression of subaortic stenosis. Cardiac catheterization performed at 2 years of age showed the pressure gradinet of 90 mmHg between the aorta and the LV. The aortic annulus and the subaortic lesion measured 10 mm and 4 mm in diameter respectively. Severe subaortic stenosis was created by protrusion of abnormal mitral tissue to the LV outflow, in addition by secondary circumferential fibrous tissue growth and hypertrophy of the ventricular septum. Konno's operation using on 18A Carbomedics valve was chosen for the certain relief of the subaortic stenosis. Although the operation required extensive ventriculotomy and septostomy because of the small aortic annulus, the postoperative course was uneventful. Two months after the operation echocardiography showed good LV function and low RV pressure of about 40 mmHg.

Aortic Valve Stenosis↗
PubMed1997

[Three-dimensional positron emission tomography imaging system and its application for medical use].

Current positron emission tomography is capable for three dimensional data acquisition and reconstruction (3D PET). The main advantage of 3D PET is its detectability for lower tracer concentrations. The images by a 3D PET have better signal to noise ratios compared to those by conventional 2D PET. This point is especially important for the studies of distributions of ligands for neuroreceptors such as F-18 FDOPA and C-11 YM-01951, since these ligands show low accumulation in brain. Reduction of scanning time is useful as well for patients are permitting extended scanning periods

Carbon Radioisotopes↗
PubMed1997

Isolation, mapping and mutation analysis of a human cDNA homologous to the doc-1 gene of the Chinese hamster, a candidate tumor suppressor for oral cancer.

We have isolated a human cDNA encoding a 115-amino-acid polypeptide that revealed 97% identity to a candidate tumor suppressor gene for oral cancer in Mesocricetus auratus (deleted in oral cancer-1; doc-1). It also showed a high degree of homology to a gene induced by TNF-alpha in Mus musculus. To investigate its possible role in esophageal carcinogenesis, we examined genetic alterations and expression levels of the gene in 13 esophageal carcinoma cell lines and 10 primary esophageal carcinomas. No mutation nor reduction of expression was observed in any of the 23 cancer materials examined. These results imply that the human doc-1 homologue is unlikely to play a significant role in esophageal carcinogenesis, although its role in the TNF-alpha signaling pathway remains unclear. We mapped DOC1 to chromosome band 12q24.31 by fluorescence in situ hybridization.

Animals↗
PubMed1997

[An experience of the modified Norwood's operation for hypoplastic left heart syndrome with aberrant origin of right subclavian artery and persistent left superior vena cava--the procedure without total circulatory arrest and cardiac arrest].

We reported a successful case of the modified Norwood operation for a 21-day-old neonate with hypoplastic left heart syndrome (MS and AS) associated with an aberrant right subclavian artery and a persistent left superior vena cava. The modified Norwood operation was performed without total circulatory arrest and Cardiac arrest. A 4 mm Gore-Tex graft, which was anastomosed between the right carotid artery and the right pulmonary artery for systemic-pulmonary shunt, was used for cerebral perfusion during aortic arch reconstruction. Coronary perfusion was performed with a small cannula placed on the relatively large ascending aorta during anastomosis between the main pulmonary artery and the ascending aorta. Equine pericardial patch was used for aortic arch reconstruction and the ascending aorta was directly anastomosed to a part of the main PA. Postoperative course was uneventful and postoperative MRI revealed no stenosis of the aortic arch and the pulmonary artery.

Aorta, Thoracic↗
PubMed1997

Internal dose estimation including the nasal cavity and major airway for continuous inhalation of C15O2, 15O2 and C15O using the thermoluminescent dosimeter method.

UNLABELLED: In the steady state method, 15O-labeled gases (C15O2, 15O2 and C15O) are administered to the body by continuous inhalation in various clinical PET studies. During inhalation, the nasal cavity and major airway may obtain a substantial amount of dose, being the source organs as well as the target organs. The internal absorbed dose to those organs and their contribution to the other target organs have not been calculated by the MIRD method. To calculate the internal dose in the MIRD method, the S values, the absorbed doses per unit of cumulated activities from nasal cavity and major airway to the other organs and vice versa, are needed, and these values are not available. METHODS: In this study, we introduced a mathematical model of the nasal cavity and major airway to calculate their S values to 23 target organs and from 11 source organs to them. Individual experiments were performed to measure the total uptake percentage and body surface doses of 15O-labeled gases from continuous inhalation. RESULTS: Using the body surface doses measured by thermoluminescent dosimeters, the cumulated activities of 11 source organs were estimated with the mathematical transformation method, and then the internal absorbed doses in 23 target organs were calculated by the MIRD method. Our experimental results were compared with the other results, and good agreements were observed. CONCLUSION: Among the target organs, the critical organ is the airway, and the absorbed dose is 2.57 x 10(-2) mGy.MBq-1.

Administration, Inhalation↗
PubMed1997

[Brain damage after surgery for thoracic aortic aneurysm].

We analyzed cases with brain damage after surgery for thoracic aortic aneurysm in our institution and investigated the causes, risk-factors and preventive measures for this disastrous postoperative complication. Irreversible brain damage was a complication in 25 out of 184 operative cases (13.6%) over a 21-year period. The cause of brain damage was determined to be embolism by manipulation of the aorta in six cases, clamping of the left subclavian artery in four cases, technical problems of separate cerebral perfusion (SCP) in four cases, severe shock in three cases, embolism unrelated to operative maneuver in three cases, stenosis of a branch of the arch with aortic dissection in two cases, and air embolism, circulatory arrest with insufficient hypothermia and hypoperfusion of a temporary bypass to the left carotid artery in one case each. The neurological symptom improved in eight cases and was unchanged in 17 cases. Eighteen cases died in the hospital. In the univariate analysis, age (p = 0.048), a portion of the aneurysm (p = 0.035), preoperative brain complication (p = 0.003), emergency operation (p = 0.033) and clamping of the arch (p = 0.001) were found to be prominent risk factors for brain damage. In the multivariate analysis, clamping of the arch (p = 0.0310), SCP (p = 0.0327) and emergency operation (p = 0.0223) were prominent. To prevent postoperative brain damage, the arch should not be clamped, appropriate operative techniques to avoid bleeding and to shorten SCP time should be employed, and proper and prompt management of the emergency operation and caution in clamping the left subclavian artery are considered to be necessary.

Adult↗
PubMed1997

[A case of rheumatoid pachymeningitis].

Here we present a 53-year-old woman with rheumatoid pachymeningitis. The subject had rheumatoid arthritis (RA) for 15 years. In April, 1996 she began to experience intermittent headaches. In September, her headaches became severe and continuous. In October, she suddenly developed ptosis of the left eye and diplopia. She also started to have dysphagia and she found it increasingly difficult to eat. She was admitted to our hospital on November 1, 1996. Neurological examinations revealed palsies of the left IIIrd, IVth, and VIth, and bilateral IXth, and Xth cranial nerves. Laboratory findings showed leukocytosis, elevated blood sedimentation rate, and positive CRP. Serum RA titer was positive (30x). The cerebrospinal fluid was normal and bacteriological examination was negative. T1-weighted MRI demonstrated hypertrophic cranial dura extending from the falx cerebri to tentorium cerebelli, which was enhanced markedly by Gd-DTPA. The dura adjacent to the cavernous sinus and the clivus were also thickened, which probably caused her cranial polyneuropathies. The dural biopsy showed massive infiltration of the inflammatory cells throughout the dura, proliferation of collagen fibers, and necrotic granuloma with neutrophilic infiltrations. Neither rheumatoid nodules, nor vasculitis were found. Despite the absence of rheumatoid nodules in the dural biopsy, the clinical features, pathologic specimens, and MRI findings of the thickened dura were most consistent with rheumatoid pachymeningitis. Administration of dexamethason ameliorated her headache on the 4th hospital day, and the cranial polyneuropathies completely disappeared on the 35th hospital day. The dural enhancement previously seen on the contrast T1-weighted MRI was diminished. Serum RA titer was also normalized (10x). Rheumatoid pachymeningitis is an extremely rare disease, and only 16 cases were reported in the literatures. Hypertrophic pachymeningitis should be considered as a diagnostic possibility in RA patients who have prolonged headache, and Gd-DTPA MRI is recommended to demonstrate the dural involvement.

Arthritis, Rheumatoid↗
PubMed1997

Epitope mapping of twelve monoclonal antibodies against the phenolic glycolipid-I of M. leprae.

Epitope mapping of 12 monoclonal antibodies (MAbs) directed to the trisaccharide part of the phenolic glycolipid-I (PGL-I) of Mycobacterium leprae was carried out by using the set of chemically synthesized sugar-BSA conjugates. The results can be summarized as follows: mAb (1-21), mAb (1-24) and mAb (1-25) recognized the outer (nonreducing end) monosaccharide of the trisaccharide chain of PGL-I. However, the affinity of these MAbs to the outer monosaccharide was weak. They required the contributions of some parts of the second sugar for enough affinity. MAbs ml 6A12, ml 8A2, ml 8B2, and PG2 B8F recognized the outer disaccharide. MAb F47-21-3 recognized the outer disaccharide and some parts of the third sugar. MAb SF 1 recognized the trisaccharide of PGL-I. MAb 3D1-A9 recognized the phenol group and the structure around the branching point on the carrier protein in addition to the trisaccharide. MAbs DZ 1 and 2G3-A8 had unique characters which recognized the inner part of the sugar chain. MAb DZ 1 recognized the inner (reducing end) disaccharide. MAb 2G3-A8 recognized the inner monosaccharide, phenol group and the structure around the branching point on the carrier protein. All of the MAbs tested, except for ml 6A12, recognized the anomeric configurations in the sugar parts they recognized; ml 6A12 recognized the anomeric configuration only within the outer disaccharide. This set of MAbs, which were well defined on their binding specificity, promises to be an effective tool for the immunological study of PGL-I and the clinical assessment of leprosy.

Antibodies, Bacterial↗
PubMed1997

Structure of DNA containing aristeromycin analog.

The melting temperatures and thermodynamic properties of several oligodeoxynucleotide duplexes containing one modified deoxyadenosine residue (carbocyclic deoxyadenosine, dAr) were investigated. It was found that the introduction of carbocyclic deoxyadenosine slightly destabilized oligonucleotide duplexes mainly due to an entropic contribution.

Adenine↗
PubMed1997

Preliminary investigation of tRNA modification enzymes with Se in bovine liver.

We measured the amount of Se in the tRNA fractions eluted from a BD-cellulose column. Se was found in the fraction eluted early from the column as to be 3 x 10(-4) mol/mol of tRNA. This low amount suggests that there is no tRNA species that contain 1 mol of Se per 1 mol of tRNA and only few specific tRNAs contain Se-nucleotides. Next, we searched the Se modification enzymes with this tRNA fraction and found the activity in cytosol. Now the digestions of the tRNA modified with 75Se was analyzed by two dimensional TLC. tRNA(Sec) of T7 transcript was not substrate for this enzyme.

Animals↗
PubMed1996

Cloning and characterization of two novel human cDNAs (NELL1 and NELL2) encoding proteins with six EGF-like repeats.

From a human fetal-brain cDNA library we isolated two novel genes encoding peptides containing six EGF-like repeats. Both showed significant homologies with nel, a gene strongly expressed in neural tissues of chicken. The cDNAs, designated NELL1 (nel-like, type 1) and NELL2 (nel-like, type 2), contained open reading frames encoding 810 and 816 amino acids, respectively. NELL2 is strongly expressed in brain of adult and fetus but only weakly in fetal kidney. NELL1 and NELL2 were mapped by FISH to chromosomal bands 11p15.1-p15.2 and 12q13.11-q13.12, respectively.

Adult↗
PubMed1996

Receptor protein tyrosine kinase DDR is up-regulated by p53 protein.

We have previously reported on radiation-induction of ptk-3 in rat astrocyte culture [Sakuma et al. (1995) Radiat. Res. 143, 1-7]. Ptk-3 was considered to be a rat version of human DDR (discoidin domain receptor). We cloned and analyzed genomic DNA of the DDR and its promoter region. We discovered that the promoter region contained a consensus sequence of the p53 tumor suppressor binding site. Adenovirus-mediated p53 transfection induced a high level of DDR mRNA in SAOS2 human osteosarcoma cells. These results indicate that DDR is up-regulated by the p53 protein.

Blotting, Northern↗
PubMed1996

Enhancement of neurite-sprouting by suppression of HPC-1/syntaxin 1A activity in cultured vertebrate nerve cells.

HPC-1/syntaxin 1A is a C-terminal anchored neuronal membrane protein, of which all of the N-terminal regions are located on the intracellular side, and it interacts with presynaptic membrane proteins, synaptic vesicle proteins and soluble N-ethylmaleimide-sensitive fusion protein attachment proteins (SNAPs). HPC-1/syntaxin 1A has been proposed to act as a target SNAP receptor (t-SNARE) in the neuron and contributes to the vesicle docking/fusion process during the fast exocytosis at the presynaptic active zone. However, studies using an electron-microscope revealed that HPC-1/syntaxin 1A distributed not only at the presynaptic region but throughout the whole axonal membrane, and the functions of this axonal HPC-1/syntaxin 1A remain completely unknown. To investigate its physiological role, we attempted to inhibit the function of HPC-1/syntaxin 1A in cultured neural cells by following two methods. First, de novo synthesis of HPC-1/syntaxin 1A was inhibited by an application of antisense oligonucleotide in cultured adult rat dorsal root ganglion (DRG) neurons. Second, antibody against HPC-1/syntaxin 1A was applied intra-axonally in the cultured chick retinal ganglion neuron. Both treatments, which were expected to downregulate the function of HPC-1/syntaxin 1A, consistently elicited an enhancement of the axonal sprouting. These results suggest that the axonal HPC-1/syntaxin 1A would physiologically suppress the excess axon-collateral sprouting. Downregulation of HPC-1/syntaxin 1A expression may underlie the control of collateral sprouting and synapse formation during development and memory processes.

Animals↗
PubMed1996

Bni1p implicated in cytoskeletal control is a putative target of Rho1p small GTP binding protein in Saccharomyces cerevisiae.

The RHO1 gene encodes a homolog of mammalian RhoA small GTP binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth sites, including the bud tip and the cytokinesis site, and is required for bud formation. We have recently shown that Pkc1p, a yeast homolog of mammalian protein kinase C, and glucan synthase are targets of Rho1p. Using the two-hybrid screening system, we cloned a gene encoding a protein which interacted with the GTP-bound form of Rho1p. This gene was identified as BNI1, known to be implicated in cytokinesis or establishment of cell polarity in S.cerevisiae. Bni1p shares homologous domains (FH1 and FH2 domains) with proteins involved in cytokinesis or establishment of cell polarity, including formin of mouse, capu and dia of Drosophila and FigA of Aspergillus. A temperature-sensitive mutation in which the RHO1 gene was replaced by the mammalian RhoA gene showed a synthetically lethal interaction with the bni1 mutation and the RhoA bni1 mutant accumulated cells with a deficiency in cytokinesis. Furthermore, this synthetic lethality was caused by the incapability of RhoA to activate Pkc1p, but not glucan synthase. These results suggest that Rho1p regulates cytoskeletal reorganization at least through Bni1p and Pkc1p.

Base Sequence↗
PubMed1996

Evidence for p53-mediated modulation of neuronal viability.

A role for p53-related modulation of neuronal viability has been suggested by the finding that p53 expression is increased in damaged neurons in models of ischemia and epilepsy. These findings were recently extended with the demonstration that mice deficient in p53 ("knock-out" mice) exhibit almost complete protection from seizure-induced brain injury, whereas wild-type mice display significant neuronal cell loss in the hippocampus and other brain regions. Because the p53 knock-out mice used in the latter study expressed a global p53 deficiency in all cell types, it was not possible to conclude that protection was conferred by the exclusive absence of p53 in neurons. Therefore, in the present study, we determined whether p53 expression in isolated neurons is directly coupled to a loss of viability associated with excitotoxic challenge. Primary cultures of hippocampal or cortical neurons were derived from animals containing p53 (+/+, +/-) or those deficient in p53 (-/-). p53-Deficient neurons appeared identical to wild-type neurons with respect to morphology, neurofilament expression, and resting levels of intracellular calcium. Neurons containing at least one copy of p53 were severely damaged by exposure to kainic acid or glutamate. Cell damage was assessed by direct cell counting and by nuclear morphology after propidium iodide staining of DNA. In contrast, neurons deficient in p53 (-/-) exhibited little or no damage in response to excitotoxin treatment. Despite their divergent outcomes, p53 (+/+) and p53 (-/-) neurons demonstrated similar sustained elevations in intracellular calcium levels triggered by glutamate exposure. Restoring p53 expression to p53-deficient neurons, using adenovirus-mediated transduction, was sufficient to promote neuronal cell death even in the absence of excitotoxin. These results demonstrate a direct relationship between p53 expression and loss of viability in CNS neurons.

Animals↗
PubMed1996

Positron emission tomography study of the alterations in brain distribution of [11C]methamphetamine in methamphetamine-sensitized dog.

We newly prepared a MAP-sensitized dog by repeated MAP treatment and studied the brain distribution of [11C]MAP in the normal and the MAP-sensitized dog using PET. The maximal level of accumulation of [11C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. No difference was found in the metabolism of MAP between the two conditions. The significant increase of [11C]MAP in the MAP-sensitized brain indicates that subchronic MAP administration causes some functional change in the uptake site of MAP. The pharmacokinetic change may, in part, account for behavioral sensitization.

Animals↗