PubMed Health⌕ Search

Biomedical subjects

T Yuasa

Publications and source records attributed to T Yuasa.

At least 163 records · Page 9Linked to original sources
PubMed1993

[Visualization of brain function using MRI-MR functional brain imaging].

The effects of photic stimulation on the visual cortex of human brain were studied by means of gradient-echo magnetic resonance imaging (MRI). Fast low-angle shot (FLASH) MRI was used to monitor changes in brain oxygenation in the human visual cortex during photic stimulation (PS). Whole-body 1.5 T clinical MR system was used. Elevation of image intensity up to 2% was observed in primary and associative visual cortex, corresponding to an increase of blood oxygenation in regions of increased neural activity. After the PS was switched off, the MR signal fell below the pre-PS baseline level, which may be understood as an displacement of the oxygen-hemoglobin dissociation curve (the Bohre effect).

Adult↗
PubMed1993

[Hereditary dentatorubro-pallidoluysian atrophy (DRPLA): clinical studies on 45 cases].

The term of dentatorubral and Pallidoluysian atrophy (DRPLA) was first introduced by Smith, who proposed that there was a combination of cerebellar ataxia with choreoathetosis based on DRPL lesions. In 1972, Naito et al. reported two families with progressive myoclonus epilepsy (PME) syndrome with cerebellar ataxia, and hyperactive deep tendon reflexes. In 1977, Oyanagi et al. reported 4 autopsied cases of PME, and pointed out degenerative lesions in the DRPL systems. In 1982, Naito and Oyanagi reported this type of PME to be hereditary DRPLA, with a clinicopathological disease entity. This type of PME with DRPLA has been made a major category, especially in Japan. In this article, clinicopathological features of the hereditary DRPLA will be reviewed on the basis of 45 patients with this disease. The disease was inherited as an autosomal dominant fashion, and induces a wide rage of clinical features depending upon the age of onset, ranging from 3 years to 69 years of age. The initial symptoms were variable according to the age of onset and mental retardation was the most prominent symptom in the patients in which the disease started in the first decade and with an epileptic seizure in the second decade. In the following next two decades, the incidence of epileptic seizure, as initial symptoms was decreased to 23% and gait disturbance and ataxia in 38% of the patients, which increased to 73% in the 5th and 6th decades. The cardinal symptoms of hereditary DRPLA includes mental retardation, epileptic seizure and myoclonus, cerebellar ataxia with gait disturbances, psychological symptoms including clonus, cerebellar ataxia with gait disturbances, psychological symptoms including character changes, and dementia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[MRI findings of olivopontocerebellar atrophy and Machado-Joseph disease--diagnostic value of transverse pontine fibers].

Olivopontocerebellar atrophy (OPCA) and Machado-Hoseph disease (MJD) occasionally show similar clinical signs and symptoms, which makes differential diagnosis of OPCA and MJD difficult. In 1990, Savoiardo et al. reported that the transverse pontine fibers of OPCA patients had high signal intensity on T2 weighted MR images. To determine if the high signal intensity of the transverse pontine fibers is useful for the differential diagnosis of OPCA and MJD, we examined this abnormal intensity in patients diagnosed as OPCA or MJD. We observed the high intensity of transverse pontine fibers in all of the 18 OPCA patients. This finding, however, was not observed in any of the patients with the MJD. The high signal intensity of the transverse pontine fibers in T2 weighted images is characteristic of OPCA patients. Furthermore the atrophy of pontine tegmentum is characteristic of patients with MJD. These findings correlate well with pathological findings of OPCA and MJD, indicating the usefulness of these MRI findings for the differential diagnosis of OPCA and MJD.

Adult↗
PubMed1993

[A case of allergic bronchopulmonary candidiasis improved with steroid inhalation].

A 49-year-old woman was admitted to hospital because of productive cough and dyspnea. She had been well two months before admission, when she developed an attack of asthma. Chest roentgenogram taken on admission revealed numerous shadows of inhomogeneous density in both lungs. Laboratory findings showed leukocytosis with eosinophilia (25%), high IgE level in serum and positive RAST score to Candida albicans. A diagnosis of allergic bronchopulmonary candidiasis was made by these laboratory data and clinical course. The patient was treated successfully by oral administration of methylprednisolone and inhalation of amphotericin B, but she had a relapse of the disease on cessation of steroid medication. Inhalation of beclomethasone dipropionate and procaterol hydrochloride was commenced. Thereafter, pulmonary infiltration and clinical symptoms improved after three weeks.

Administration, Inhalation↗
PubMed1992

Ca(2+)-dependent protein kinase from the halotolerant green alga Dunaliella tertiolecta: partial purification and Ca(2+)-dependent association of the enzyme to the microsomes.

Ca(2+)-dependent protein kinase (CDPK) was purified 900-fold from the soluble fraction of Dunaliella tertiolecta cells by ammonium sulfate precipitation, DEAE-Toyopearl, phenyl-Sepharose, and hydroxylapatite column chromatography. The CDPK was activated by micromolar concentration of Ca2+ and required neither calmodulin nor phospholipids for its activation. The enzyme phosphorylated casein, myosin light chain, and histone type III-S (histone H-1), but did not phosphorylate protamine and phosvitin. The Km values for ATP and casein were 11 microM and 300 micrograms/ml, respectively. Phosphorylation of casein was inhibited by calmodulin antagonists, calmidazolium, trifluoperazine, and compound 48/80, but not affected by calmodulin. CDPK bound to phenyl-Sepharose in the presence of Ca2+ and was eluted by ethylene glycol bis(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA). This suggests that hydrophobicity of the enzyme was increased by Ca2+. CDPK was also bound to the microsomes isolated from Dunaliella cells in the presence of micromolar concentration of Ca2+ and released in the presence of EGTA, suggesting the possibility of in vivo Ca(2+)-dependent association of the enzyme. The enzyme phosphorylated many proteins in the microsomes but few in the cytosol, if at all.

Calmodulin↗
PubMed1992

[A hereditary ataxia associated with hypoalbuminemia and hyperlipidemia--a variant form of Friedreich's disease or a new clinical entity?].

The patients belonged to three different families and were products of consanguineous marriage. The neurological symptoms and signs in these patients began in infancy or childhood and included gait disturbance, horizontal nystagmus, distention tremor of the hands, muscular wasting and sensory impairment of the hands and legs. CT-scan and/or MRI showed atrophy of the cerebellum. Serum biochemical analyses revealed hypoalbuminemia with hyperlipidemia. There were no abnormalities in the heart, liver, kidney, gastrointestinal tract, or endocrine systems. The autopsy revealed degenerative changes in the spinal cord including posterior column and lateral pyramidal tract, as well as in the peripheral nerves and cerebellar cortex. Although we have speculated that the disease presented here would be a clinical variants of Friedreich's disease, it would make a new clinical entity because there was no report about the association to hypoalbuminemia and hyperlipidemia with spinocerebellar degeneration.

Adult↗
PubMed1992

[Primary effect of preoperative intra-arterial infusion chemotherapy in cervical cancer].

In order to obtain better prognoses for cervical cancer, we conducted preoperative intra-arterial (i.a.) infusion chemotherapy of CDDP in combination with AT-II pressor. Two courses of i.a. chemotherapy were performed for 67 patients with cervical cancer in stage IIb containing 54 squamous cell carcinomas and 13 adenocarcinomas before operation every 3 weeks. A histologically desirable effect in cervical lesion was obtained. A group given preoperative i.a. chemotherapy had a significantly lower rate of infiltration beyond uterus in comparison with 156 patients with 145 squamous cell carcinomas and 11 adenocarcinomas treated by surgery alone as the control group. Further, the rate of histological infiltration to parametrial edges after i.a. chemotherapy tended to be lower than the control group. From the above, it was considered that preoperative i.a. infusion chemotherapy of CDDP in combination with AT-II pressor for cervical cancer was effective as a neo-adjuvant chemotherapy.

Adenocarcinoma↗
PubMed1992

[Extrapleural approach for patent ductus arteriosus and coarctation of the aorta].

During the period of 1989 to 1990, 6 consecutive children with patent ductus arteriosus or coarctation of the aorta underwent operative therapy. Ligation or division of patent ductus arteriosus or subclavian flap angioplasty for coarctation of the aorta were performed by extrapleural approach with axillary or posterolateral incision. Patients' ages ranged from 9 days to 8 years. Weights ranged from 3 to 30 kg. It was very easy to have better operative field and beneficial to protect the lung against mechanical injury. Extrapleural approach was not so easy in an 8-year-old patient with firm connective tissue. Therefore, this procedure is considered to be suitable for younger children.

Aortic Coarctation↗
PubMed1992

[Hereditary dentatorubropallidoluysian atrophy--clinical variants in a family and degeneration of cerebral white matter in a proband].

We describe a family with hereditary dentatorubropallidoluysian atrophy (DRPLA). 4 patients through 3 successive generations showed a wide clinical variety. The female proband with onset in the elderly developed choreiform involuntary movement, dementia, hyperreflexia and, at the progressive stage, mild ataxia. However she had never displayed epilepsy and myoclonus. The 2 sons showed dementia, choreoathetoid movement and ataxia. The grandson developed typical signs and symptoms of progressive myoclonus epilepsy. The brain CT in the proband showed severe cerebellar and brain stem atrophy, moderate cerebral cortical atrophy and diffuse low density lesions in the deep cerebral white matter. Her neuropathological examination revealed the atrophy and gliosis of cerebral and cerebellar white matter concomitant with both dentatorubral and pallidoluysian system degeneration. The present study indicates that hereditary DRPLA can include multiple clinical variants even in the same family and the degeneration of cerebral and cerebellar white matter besides dentatorubral and pallidoluysian system.

Adolescent↗
PubMed1992

[Staged sternal closure for the case of postoperative severe cardiac failure: a convenient method in the intensive care unit].

A convenient method of staged sternal closure in the intensive care unit for a patient with severe cardiac failure was reported. According to the patient's cardiac function, optimal intersternal space can be adjusted. When using this method on a infant, the adjustment has shown to be very easy and take only a short time. However we have no experience on adults with stronger sternum.

Cardiac Output, Low↗
PubMed1992

[Carpentier's procedure for Ebstein's anomaly: successful and failed cases].

Two adult cases of Ebstein's anomaly underwent Carpentier's procedure. In the first case longitudinal plication limited to free wall of atrialized ventricle was performed and postoperative course was uneventful. In the second case preoperative echocardiography showed apparently restricted movement of anterior leaflet of the tricuspid valve which was compatible with intraoperative findings. That is, inferior edge of anterior leaflet was partly adherent to ventricular wall and systolic bulging of leaflet was significantly impaired which was left untouched but should be repaired by additional procedure. Six days after operation the tricuspid valve replacement was required for persistent right heart failure due to residual tricuspid regurgitation. In the same case longitudinal plication of atrialized ventricle reported by Carpentier and colleagues resulted in excessively small annulus. Therefore we had to reduce the plication and did not perform following atrial plication to avoid direct injury to conduction system or disturbing coronary venous return. In conclusion exact preoperative evaluation of anterior leaflet of the tricuspid valve especially subvalvular anatomy is essential to Carpentier's procedure, as Carpentier and colleagues emphasized, and conservative longitudinal plication of the atrialized ventricle limited to free wall is favorable when excessively small annulus might be concerned.

Cardiac Surgical Procedures↗
PubMed1992

[An acute axonal polyneuropathy affecting intrinsic hand muscles following Campylobacter infection--a case report].

A 24-year-old carpenter had the shakes and fever on March 13, 1990. He suffered from watery diarrhea on March 14 and 15. He left muscle weakness in his thumbs and fingers when he drove nails with a hammer on March 24. The weakness reached maximum by the 3rd day of illness. He was admitted to our hospital on day 4. Neurological examination revealed symmetrical weakness localized in the intrinsic hand muscles (MRC grade 2-4). The deep tendon reflexes were preserved. Sensation was intact except for mild disturbance of superficial sense on both plantar areas. Campylobacter jejuni was cultured from his stool. A complement fixation test indicated serologically preceding C. jejuni infection. Whereas maximum motor nerve conduction velocities were not reduced and distal latencies were not prolonged, compound muscle action potential recorded in the thenar and hypothenar muscles were remarkably reduced on day 5. Needle EMG showed neuropathic changes in four limbs. Sensory nerve conduction velocities and action potentials were normal. The weakness gradually improved in association with increased compound muscle action potentials in the thenar and hypothenar muscles. His muscle symptom fully resolved 2 months after the onset of his illness. Thin-layer chromatogram with immunostaining revealed that serum IgG from this patient reacted with GM1, GD1a, GD1b, but did not react with GM2 and GT1b. Enzyme-linked immunosorbent assay showed that anti-GM1, GD1a, GD1b antibodies titer (IgG) decreased concurrently with the clinical improvement.

Acute Disease↗
PubMed1991

Study on the erythrocytes from myotonic dystrophy with multi-nuclear NMR.

We have studied the water permeability through membranes, the function of the Na pump, and glucose metabolism of erythrocytes of patients with myotonic muscular dystrophy (MyD) using 1H--, 23Na, and 13C-NMR techniques. A significant decrease in water permeability was recognized in the MyD erythrocyte membrane, and impaired Na pumping was suspected to be correlated with the former biochemical abnormalities in band III protein of MyD erythrocyte membrane. Significant acceleration of glycolysis in the erythrocyte for the first 160 minutes was also recognized in MyD; however, the production of lactate showed no difference between MyD and controls. The increased glucose uptake in MyD may be compensatory to the diminished pumping mechanism, but further information, such as inorganic phosphate permeability and the activity of the rate-limiting enzyme of erythrocyte glycolysis, is needed.

Adolescent↗
PubMed1991

Preferential expression of the large hepatitis B virus surface antigen gene by an adenovirus-hepatitis B virus recombinant.

Using an adenovirus-hepatitis B virus (HBV) recombinant, expression of the HBV surface antigen (HBsAg) genes was examined in various cell lines using S1 nuclease mapping and radioimmunoassay. The steady-state level of the 2.4 kb RNA encoding the large HBsAg was much greater than, or the same as, that of the 2.0 kb RNA, encoding the middle and major HBsAgs, in primate cells, but was negligible in non-primate cells, as is the case in most expression systems. According to the amount of 2.4 kb RNA expressed, cells were classified into three groups: those in which (1) the amount of 2.4 kb RNA was much greater than that of 2.0 kb RNA (HepG2 and JHH-4), (2) the amount of 2.4 kb RNA was the same as that of 2.0 kb (Hul-1, HeLa and other non-hepatic primate cells), and (3) the amount of 2.4 kb RNA was less than one-tenth of that of 2.0 kb RNA (rodent cells). Radioimmunoassay revealed that most HBsAg is located intracellularly in primate cells, but is secreted into the culture medium of rodent cells. The expression of 2.4 kb RNA was unaffected by an inhibitor of DNA synthesis in HepG2 cells, which are of human liver origin, whereas it was strongly inhibited in human non-hepatic HeLa cells.

Adenoviridae↗
PubMed1991

The particle size of hepatitis C virus estimated by filtration through microporous regenerated cellulose fibre.

To estimate the particle size of hepatitis C virus (HCV), a major causative agent of post-transfusion non-A, non-B hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. The amount of HCV particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (PCR) method. Since there is no quantitative biological assay for HCV, except for that in chimpanzees, the HCV titre obtained from the PCR method was used in an equation constructed previously for application to filtration experiments with a flavivirus which is distantly related to HCV. The particle was estimated to be between 30 and 38 nm in diameter, although the possibility remained that larger HCV particles or HCV aggregates with a diameter of more than 39 nm might exist. Double-step filtration through microporous cellulose fibres with a pore size of 35 nm reduced the HCV content to below levels detectable by our PCR method, indicating that it is possible to eliminate HCV particles by simple filtration techniques.

Base Sequence↗