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Biomedical subjects

T Yuasa

Publications and source records attributed to T Yuasa.

At least 181 records · Page 10Linked to original sources
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↗
PubMed1991

[Analysis of factors influencing early patency of saphenous vein grafts].

To determine factors affecting early patency of saphenous vein grafts, 140 grafts in 65 patients were studied angiographically within 2 months after operation. Twenty of the 140 grafts were occluded. Sixteen variables were extracted from the angiographic findings, intraoperative measurements, clinical characteristics, and biochemical data. The univariate and multivariate analyses were performed to assess their predictive value. Of 16 variables, 3 (coronary artery internal diameter, graft flow, and coronary artery resistance) correlated significantly with graft patency in the univariate analysis. The multivariate analysis selected coronary artery resistance, coronary artery internal diameter, and degree of proximal stenosis as predictors of early graft patency. Of these 3 factors, the coronary artery resistance influenced graft patency mostly. Therefore, the coronary artery resistance was considered to be the most reliable predictor of early graft patency.

Adult↗
PubMed1991

[A case of cerebrotendinous xanthomatosis with spastic paraparesis, epilepsy, and bradykinesia].

A 26-year-old female developed mental deterioration, general convulsion, cataract and spastic gait in order since her entrance into elementary school. A diagnosis of cerebrotendinous xanthomatosis (CTX) was made because of hypercholestanolemia. At the time of admission, cataract, a mild thickening of Achilles tendons, mental deterioration, spastic paraparesis, truncal ataxia, and bradykinesia were noted. Bilateral slowing of 2 to 7 Hz was recorded in EEG, and brain CT and MRI revealed mild cerebellar atrophy. HVA and 5-HIAA levels in CSF were low. Oral administration of chenodeoxycholic acid, 300 mg per day, resulted in improvement of bradykinesia and EEG abnormality, increase of HVA and 5-HIAA levels in CSF, and decrease of serum cholesterol level in two weeks. Bradykinesia observed in the present case is a rare clinical finding of CTX, and the improvement of bradykinesia soon after the treatment with chenodeoxycholic acid has not been reported yet. This case is important for elucidating the mechanism of neurological disorders in CTX.

Adult↗
PubMed1991

Stereographic demonstration of the nasal cavity of the rat with reference to the density of blood vessels.

Stereographic demonstration of the nasal cavity and distribution of the density of blood vessels were analyzed by computer simulation of serial sections of the rat nose. The nasal cavity was lined by 3 types of epithelium: Stratified epithelium covering the nasal vestibule, the anterior part of the maxilloturbinale, and the anterior part of the septum; respiratory epithelium covering most of the naso- and maxilloturbinalia, and middle part of the septum; and olfactory epithelium covering most of the ethmoturbinale and postero-dorsal part of the septum. Distribution of densities of blood vessels in the lamina propria of the nasal mucosa was roughly correlated with the distribution of the 3 types of epithelium: 194 blood vessels/mm2 of lamina propria beneath the olfactory epithelium; 82 vessels/mm2 beneath the stratified epithelium; and 66 vessels/mm2 beneath the respiratory epithelium. The average density of blood vessels in the nasal cavity was 3.8 times higher than that of the oral cavity. The high density of blood vessels in the nasal cavity was considered to be related to the function of the nose, i.e., the warming and humidification of inspired air.

Animals↗
PubMed1990

Sequence determination of the hemagglutinin-neuraminidase (HN) gene of human parainfluenza type 2 virus and the construction of a phylogenetic tree for HN proteins of all the paramyxoviruses that are infectious to humans.

The nucleotide sequence of the hemagglutinin-neuraminidase (HN) gene of human parainfluenza type 2 virus (PIV-2) was determined. The PIV-2 HN gene was 2112 nucleotides excluding poly(A) tail. There was a single large open reading frame in the mRNA which encoded a protein of 571 amino acids with a calculated molecular weight of 63,262. Analysis of the deduced amino acid sequence revealed that there were fourteen potential glycosylation sites and a major hydrophobic region near the N-terminus, which would anchor the protein in the viral membrane. Comparisons of the HN protein sequences of PIV-2 with those of Simian virus 5 (SV5), Sendai virus (SV, parainfluenza virus type 1), human parainfluenza virus type 3 (PIV-3), type 4 (PIV-4), bovine parainfluenza virus type 3 (BPIV-3), mumps virus (MuV), and Newcastle disease virus (NDV) showed definite amino acid sequence relatedness, indicating a common ancestor for these viruses. Furthermore, statistical analysis of the protein sequences suggested a possible evolutionary relatedness among the paramyxoviruses. This is the first time that a phylogenetic tree has been constructed for all the parainfluenza viruses and mumps virus which are infectious to humans. In addition, amino acid sequences involved in hemagglutinating and neuraminidase activities of paramyxovirus were discussed.

Amino Acid Sequence↗
PubMed1990

Effect of the preS1 RNA sequence on the efficiency of the hepatitis B virus preS2 and S protein translation.

The gene coding for hepatitis B virus surface antigen consists of preS1, preS2, and S regions. Two species of mRNAs of this gene are transcribed. The larger species covers all three regions and is translated solely into preS1 protein, whereas the smaller one covers the preS2 and S regions and is translated into preS2 and S proteins. This study examines the influence of the 5' upstream sequence lying in the preS1 region on the synthesis of preS2 and S proteins. For this purpose, several expression plasmids were constructed by inserting various portions of the preS1 region between the retroviral LTR promoter and the preS2/S coding region, and preS2/S protein production was examined in the transfected CHL cells. All the transcripts were initiated in the LTR. A sequence located in the region between 102 and 38 nucleotides upstream from the preS2 initiation codon was found to reduce the production of preS2/S proteins probably at the level of translation. Expression of the heterologous chloramphenicol acetyltransferase gene was similarly inhibited when it was placed downstream of the preS1-102/-38 sequence.

Animals↗
PubMed1990

Sequence analyses of the 3' genome end and NP gene of human parainfluenza type 2 virus: sequence variation of the gene-starting signal and the conserved 3' end.

We cloned and determined the nucleotide sequences of cDNAs against nucleocapsid protein (NP) mRNA and the genomic RNA of human parainfluenza type 2 virus (PIV-2). The 3' terminal region of genomic RNA was compared among PIV-2, mumps virus (MuV), Newcastle disease virus (NDV), measles virus (MV), PIV-3, bovine parainfluenza type 3 virus (BPIV-3), Sendai virus (SV), and vesicular stomatitis virus (VSV), and an extensive sequence homology was observed between PIV-2 and MuV. Although no significant sequence relatedness was observed between PIV-2 and other viruses, the terminal four nucleotides were identical in the viruses compared, implying a specific role of these nucleotides on the replication of paramyxoviruses. A primer extension analysis elucidated the major NP mRNA initiation site with the sequence UCUAAGCC, which showed a moderate homology with the gene-starting consensus sequences of other paramyxoviruses. On the other hand, the NP mRNA was terminated at the nucleotide stretch AAAUUCUUUUU, and this sequence was conserved in all the PIV-2 genes, indicating that the oligonucleotides will form a part of the gene attenuation signal of PIV-2. Comparisons of NP protein sequence indicated a possible subgrouping of the paramyxoviruses into two groups, one of which is a group including PIV-2, PIV-4, MuV, and NDV, and another is a group including PIV-3, BPIV-3, and SV. This result supports an idea from our previous studies using polyclonal and monoclonal antibodies. Furthermore, our data indicated that the PIV-2 NP protein sequence was more closely related to MV and CDV than to other parainfluenza viruses, PIV-3 and SV.

Amino Acid Sequence↗
PubMed1990

Detection of hepatitis C virus cDNA sequence by the polymerase chain reaction in hepatocellular carcinoma tissues.

We found the presence of hepatitis C virus (HCV) infection in liver tissues of hepatocellular carcinoma (HCC) patients who had antibodies to HCV but no serological markers for hepatitis B virus infection by the sensitive reverse transcription/polymerase chain reaction (R/PCR) method. The primers used were derived from the non-structural (NS) 3 and/or the structural (C/E) region. Amplified cDNA sequences of HCV were detected in either cancerous or non-cancerous portion of liver tissues from four out of eight HCC patients with primers of NS3 region. Similar but less efficient results were obtained with primers of C/E region. These results indicate that HCV persists in the liver tissue of HCC. A possible role of persistent infection of HCV for the development of HCC is discussed.

Base Sequence↗
PubMed1990

[An autopsied case of manifesting chorea, serum antibody to brain proteins, neuronal degeneration in striatum and grumose degeneration in dentate nucleus].

A 49-year-old man complained of difficulty in writing due to choreic involuntary movement in the right hand, which spread gradually to his left hand, face, lower extremities and trunk during next nine years. He also showed difficulties in speech and swallowing. His family noticed his memory disturbance and change of his character. Ten years later, mental deterioration, dysarthria and dysphagia were manifested. He showed facial grimacing and dancing gait. Deep tendon reflexes were exaggerated with no pathological reflexes. Muscle tone was rigid at his ankles. He showed no ataxia nor sensory impairment. At about 61 years old, choreic movement was decreased and rigidity spread in all extremities with joints' constructure. During next one or two years, choreic movement diminished and was restricted to his face. The extremities became more rigid and voluntary movement was severely impaired. He became mutistic with severe mental deterioration. He died at the age of 65. None of his family suffered from the same disease. Routine blood examination was normal, and there were no acanthocytes. Brain CT showed marked dilatation of lateral and third ventricles, and mild cerebral cortical atrophy. The head of caudate nucleus was also atrophic. The total protein level in the CSF was elevated to 79-121 mg/dl, and IgG% was 13.7-26.6 for last six years. Anti-CNS antibodies in the serum reacted with brain proteins of 156 kDa and 82 kDa. Pathological examination showed severe atrophy of the caudate nucleus, putamen, globus pallidus, cerebral cortex and cerebral white matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Clinical features of uveitis in childhood during the past 20 years].

One hundred and fifty five cases (237 eyes) of children with uveitis were clinically observed in the past 20 years. There was no fluctuation in the number of patients during the period. Concerning the age as the first visit, the smallest group was under 4 years of age and the numbers of patients increased at ages 14 and 15. Chief complaints usually corresponded to the age of the cases. Cases with anterior uveitis accounted for 25% of all cases, intermediate uveitis 12%, posterior uveitis 45% and panuveitis consisted of 17% of all cases, respectively. In the course of treatment, improvement of visual acuity was not statistically significant; the visual prognosis of cases affected under age 7 years was relatively poor. At the time of final observation, the visual acuity of cases, who had first visited during the past 10 years, were better than those who presented during the previous decade. Uveitis had healed or improved in 68% of cases treated in our clinic. As complications, band-shaped keratopathy was seen in 8% of the patients, cataract in 22% and glaucoma in 5%, respectively. Thirty two per cent of the cases received systemic steroid therapy and the average duration was 3.8 months. Fifty two operations were performed in 30 cases (19%), 37 eyes (16%); 16 were cataract operations and 24 were operations for glaucoma.

Adolescent↗
PubMed1990

[Auditory brainstem response and somatosensory evoked potential in Machado-Joseph disease in Japanese families].

To clarify physiological aspects of Machado-Joseph disease (MJD), we studied auditory brainstem response (ABR) and somatosensory evoked potential (SEP) in 17 clinically diagnosed patients with MJD aged 32-64 in Japanese families. ABR was recorded in 13 patients. In 8 patients, ABR were abnormal. In 5 patients, the latency of I wave was normal, but other waves could not be evoked. In the other 3 patients, I-III interpeak latency was prolonged. SEP was recorded in 15 patients. In SEP of median nerve, 11 patients had abnormal findings, and SEP of posterior tibial nerve revealed abnormal findings in all 15 patients. In all patients, responses from Erb's point and popliteal fossa were normal in latency, but other peaks were low in amplitude or absent, and the latency and central conduction time (CCT) were prolonged. The result of ABR indicated the involvement of the brainstem auditory pathways in MJD, and the result of SEP suggested that somatosensory pathways, particularly central pathways, would be involved in the disease process. ABR and SEP can be potential diagnostic methods for detection of subclinical abnormality in MJD patients.

Adult↗
PubMed1989

NMR study on [1-13C]glucose metabolism in the rat brain during hypoxia.

The metabolism of [1-13C]glucose in the rat brain during hypoxia was investigated by 13C NMR spectroscopy. Male Wistar rats, weighing 100-120g, were anesthetized with ketamine (50 approximately 75 mg/kg i.p.) and ventilated mechanically with a mixture of 30% oxygen, 69.5% nitrogen and 0.5% halothane. [1-13C]glucose (250 mg/kg) was infused twice, at 10 minute intervals, through the femoral vein. For the control group (n = 4), the oxygen concentration of the inspiratory gas was maintained at 30% by vol throughout the experiments. For the hypoxia group (n = 6), the oxygen concentration in the inspiratory gas was reduced to 6-7% (93-94% nitrogen) and maintained for 30 min following [1-13C]glucose infusion. 13C NMR spectra were measured by a gated proton-decoupling method without a nuclear Overhauser effect. The [1-13C]glucose infusion gave apparent signals of the C1 carbon in the alpha- and beta-anomers of [1-13C]glucose at 92.7 and 96.7 ppm, respectively. Signals of the C2, C3 and C4 carbon atoms in glutamate and/or glutamine (glx) also appeared at 55, 27 and 34 ppm, respectively. The intensity of glx-C2 and glx-C3 signals increased later than that of glx-C4. The time lag between the different glx signals may reflect the turnover rate of the TCA cycle. Under the hypoxic condition, the signal of C3 carbon in lactate appeared at 21 ppm and increased. The alpha-glucose signal diminished during hypoxia, whereas the beta-glucose signal kept its intensity. The difference in changes of the signal intensity between alpha- and beta-glucose suggests that alpha-glucose is consumed more than beta-glucose in the hypoxic brain.

Animals↗
PubMed1989

[Acute autonomic and sensory neuropathy associated with galactorrhea-amenorrhea syndrome and intractable anorexia].

Acute autonomic and sensory neuropathy (AASN), one subtype of acute pandysautonomia, in which dorsal root ganglia and autonomic ganglia are involved is uncommon. Little is so far known on central nervous system involvement in AASN. In the present paper we described a rare case of AASN associated with the central nervous system manifestations such as galactorrhea-amenorrhea syndrome and intractable anorexia. A 30-year-old woman rapidly developed burning pain and numbness in her arms and legs as well as orthostatic syncope. She had severe anorexia and no no menstruation from onset. On physical examination, she was emaciated. There was marked orthostatic hypotension with tachycardia. Skin was dry. Moderate galactorrhea was detected. Neurological examination showed prominent paresthesia and dullness of superficial sensation, predominantly to pinprick and thermal stimuli, segmentally over the neck, occipital scalp, and extremities. Deep sensation was intact. She had no weakness or ataxia. Deep tendon reflexes were almost normal. NCV and SEP were normal, while EEG was abnormal. Sural nerve biopsy demonstrated axonal degeneration with the loss of myelinated, predominantly in small-caliber fibers, and unmyelinated fibers. The levels of HVA and MHPG in CSF were decreased. The autonomic nervous function tests revealed postganglionic dysfunction. alpha-adrenergic system was predominantly impaired, while beta-adrenergic system was relatively preserved. The endocrinological studies demonstrated mild or moderate elevation of PRL basal value and hyper-response of PRL and LH for TRH and LH-RH loading test, which suggested disorder of the hypothalamo-hypophysial system. Cranial MRI showed moderate dilatation of the 3rd ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

[Subacute sensory neuropathy manifestated by tonic pupils associated with small cell carcinoma of the lung].

Only a few cases of carcinomatous neuropathy with tonic pupils have been reported. In the present paper we described a 53-year-old woman with subacute sensory neuropathy who had presented with bilateral tonic pupils. She noticed numbness over the medial aspect of the left thigh in March, 1988, and then developed dysesthesia over the left forearm and hand, mild weakness of left upper and lower extremities and urinary disturbance. Neurological symptoms were subacutely progressive and she was bed-ridden in May. She was admitted to our hospital in June, 1988. On examination, she had body-weight loss of 6 kg during the last six months and general status was otherwise unremarkable. She had anisocoria; the left pupil was larger in daylight than the right, while smaller in dim light. The left pupil scarcely reacted to light, but promptly constricted to near vision. The right pupil constricted normally to light and near vision. An instillation of 0.0625% pilocarpine solution showed supersensitive response of both pupils. An instillation of 1.25% epinephrine solution demonstrated mild dilation of both pupils. Thus, it was conceivable that she had postganglionic ciliary nerve damage characteristic of tonic pupil as well as the lesion of sympathetic nerve innervating pupillary dilator. She had severe sensory ataxia and pseudoathetosis of the hands. Weakness was mild to moderate in extremities. Almost all deep tendon reflexes were absent. All modalities of sensation, particularly on deep sense, were severely involved with sea-level-type distribution below Th7, and over C2 to C3 regions on the left side.(ABSTRACT TRUNCATED AT 250 WORDS)

Autonomic Nervous System Diseases↗
PubMed1989

[A case of amyotrophic lateral sclerosis associated with clinical features of progressive supranuclear palsy].

A 64-year-old male patient of amyotrophic lateral sclerosis (ALS) with frozen gait, axial rigidity and supranuclear upper gaze palsy was reported. We have followed this patient more than four years. He was well until November 1982, when he noticed weakness of left arm. In March 1983, he noticed hypogeusia and in July, he developed dysarthria and frozen gait. On admission, he was alert and oriented. Neurological examination revealed dysarthria, dysphagia and muscular weakness and atrophy in bilateral upper extremities, dominantly in left side. He showed remarkable frozen gait, retropulsion and could not walk. Brain CT showed mild dilatation of the third ventricle. In August 1988, he showed tongue atrophy, and weakness and atrophy of the extremities progressed during these four years. He also showed axial rigidity and frozen gait. Brain CT showed severe third ventricular dilatation and atrophy of tegmentum of the midbrain and cerebellum that were compatible with progressive supranuclear palsy (PSP). Six months later, he developed upper gaze palsy. From these findings, we concluded that this patient had a quite unique clinical features of both ALS and PSP.

Amyotrophic Lateral Sclerosis↗