Biomedical subjects

T Yuasa

Publications and source records attributed to T Yuasa.

At least 37 records · Page 2Linked to original sources

PubMed2001

Postural sway during cane use by patients with stroke.

OBJECTIVE: To quantitatively evaluate the effects of body support with a cane on postural sway by measuring gravity-center sway of patients with stroke who reside at home. DESIGN: The subjects were 41 patients with stroke and 36 healthy independent elderly people. Each subject stood in the standard Romberg position on a gravicorder under two conditions: without support and with a cane. RESULTS: In both groups, the largest area of gravity-center sway occurred when the subjects stood without support. The area of gravity-center sway of the patients with stroke was significantly greater than that of the healthy independent elderly. In the patients with stroke group, the percentage decrease in the standing position with the cane was 58.0% in the men and 53.9% in the women, as opposed to 67.7% in the men and 67.8% in the women in the group of healthy independent elderly. CONCLUSION: The authors quantitatively evaluated the effects of body support with a cane on postural sway of patients with stroke. The effect of body support with cane on postural sway of patients with stroke was more effective than that of healthy independent elderly.

Aged↗

PubMed2001

A eukaryotic-type protein kinase, SpkA, is required for normal motility of the unicellular Cyanobacterium synechocystis sp. strain PCC 6803.

The genome of the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 comprises many open reading frames (ORFs) which putatively encode eukaryotic-type protein kinase and protein phosphatase. Based on gene disruption analysis, a region of the hypothetical ORF sll1575, which retained a part of the protein kinase motif, was found to be required for normal motility in the original isolate of strain PCC 6803. Sequence determination revealed that in this strain sll1575 was part of a gene (designated spkA) which harbored an entire eukaryotic-type Ser/Thr protein kinase motif. Strain ATCC 27184 and a glucose-tolerant strain derived from the same isolate as the PCC strain had a frameshift mutation dividing spkA into ORFs sll1574 and sll1575. The structural integrity of spkA agreed well with the motility phenotype, determined by colony morphology on agar plates. The spkA gene was expressed in Escherichia coli as a His-tagged protein, which was purified by Ni2+ affinity chromatography. With [gamma-32P]ATP, SpkA was autophosphorylated and transferred the phosphate group to casein, myelin basic protein, and histone. SpkA also phosphorylated several proteins in the membrane fraction of Synechocystis cells. These results suggest that SpkA is a eukaryotic-type Ser/Thr protein kinase and regulates cellular motility via phosphorylation of the membrane proteins in Synechocystis.

Amino Acid Sequence↗

PubMed2001

Bilevel nasal positive airway pressure and ballooning of the stomach.

We describe a case of severe gastric insufflation in a patient with amyotrophic lateral sclerosis who was receiving bilevel nasal positive airway pressure (BNPAP) ventilation (BiPAP; Respironics; Murrysville, PA). The injection of inspiratory flow into the esophagus, aerophagia, and air trapping below the gastroesophageal junction after a meal are probably the major causes. We suggest that BNPAP ventilation can be a cause of serious gastric insufflation in a patient who lies supine, especially after a meal, and attention should be paid to avoiding this complication by having the patient sit up for about half an hour after a meal.

Adult↗

PubMed2001

Quantitative EEG data and comprehensive ADL (Activities of Daily Living) evaluation of stroke survivors residing in the community.

The purpose of this study was to investigate the hypothesis that EEG values match other comprehensive activities of daily living (ADL) evaluations between stroke survivors and normal controls. Various functions related to ADL were examined by means of ADL assessments (Measurement of Competence in the Elderly Living at Home, Barthel Index, Stroke Impairment Assessment Set, time needed to walk 10 metres) and biosocial synchronization (the questionnaire on biosocial rhythms of daily living). EEG was undertaken using a computer-assisted portable EEG recorder. The power spectra were computed using a fast Fourier transformation analysis (FFT). The absolute and relative powers (percent of the total EEG power) of 5 frequency bands (delta, theta, alpha 1, alpha 2 and beta) and the peak frequency were analyzed. In comparing stroke survivors and the independent elderly, the latter had higher scores than the former in assessments of various functions related to ADL. The absolute and relative power of the delta band were lower in normal controls, and the relative power of the alpha (2) band and the peak frequency were higher than those of stroke survivors. Among the correlations between EEG and ADL assessments, the absolute and relative power of the alpha (2) band correlated significantly with ADL assessments of stroke survivors with right hemiplegia. The peak frequency was significantly increased in cases with high ADL scores. In conclusion, significant correlations were identified between the quantitative EEG data of stroke survivors in the chronic stage, living in the community, and ADL-related functions. Computer-assisted portable EEG recording is a potentially useful screening tool for objectively evaluating the functional levels of stroke survivors in field work.

Activities of Daily Living↗

PubMed2001

Expression patterns of cancer testis antigens in testicular germ cell tumors and adjacent testicular tissue.

PURPOSE: The human cancer-testis antigens (CTAs) are a group of tumor specific antigens recognized by cytotoxic T lymphocytes whose expression occurs in human malignancies as well as in normal testicular tissue. We studied a series of CTA gene transcripts in testicular germ cell tumors of various histological types to test the hypothesis that the expression of CTA in testicular germ cell tumors reflects developmental stages of tumorigenesis rather than constitutive tumor antigens recognized by cytotoxic T lymphocytes. MATERIALS AND METHODS: Total RNA was obtained from 31 primary and 3 metastatic testicular germ cell tumors, and 11 parenchymal tissues adjacent to the testicular germ cell tumors. We performed an expression study of the CTA genes MAGE-A, MAGE-B, GAGE, PAGE-1, HOM-MEL-40 (SSX2), NY-ESO-1, LAGE-1 and SCP-1 in these samples using reverse transcriptase-polymerase chain reaction. RESULTS: The results showed that expression patterns of CTA genes depended on the histological differentiation of the testicular germ cell tumors. Overall CTA expression was more common in seminomas than in nonseminomatous germ cell tumors. Specifically all 13 seminomas (100%) demonstrated the positive expression of MAGE-B1 and MAGE-B2, while 3 of 17 nonseminomatous germ cell tumor samples (18%) showed positive expression of these genes. All 5 teratomatous elements (100%) had homogenous null expression with regard to all CTA genes examined. In addition, we detected deficiencies in CTA expression in 7 of 11 parenchymal tissues adjacent to the testicular germ cell tumors (64%). CONCLUSIONS: These data support the idea that CTA transcripts in testicular germ cell tumors serve as developmental footprints of testicular germ cell tumors rather than as constitutive tumor antigens recognized by cytotoxic T lymphocytes.

Antigens, Neoplasm↗

PubMed2001

Preputial calculi: a case report.

The patient was a 92-year-old male whose chief complaint was urinary retention. The X-ray film showed multiple overlapping calcification shadows in the penile region. Renal insufficiency was speculated to be due to post-renal obstruction. Under the diagnoses of closure of the preputial orifice by balanoposthitis followed by urinary retention and preputial calculi, an urgent dorsal incision of the prepuce was made. Then, stone removal and indwelling catheter placement were performed. Renal function recovered soon after the operation, and the patient could urinate freely without catheterization. This case reminds us of the significance of surgical treatment for phimosis in elderly patients.

Aged↗

PubMed2001

[A case of cerebellar degeneration with schizophrenia-like psychosis, severe iron deficiency, hypoceruloplasminemia and abnormal electroretinography: a new syndrome?].

A 33-year-old male patient began to develop schizophrenia-like symptoms and slowly progressive cerebellar ataxia. He was 170 cm tall and he had mild frontal baldness. Psychiatrically he was aconative, only willing to do nothing all day long after admission. He had neither hallucinations nor delusions, and his mental acuity was normal. Neurological examination revealed positive cerebellar signs including clumsiness in F-N-T and K-H-T and dysdiadochokinesis. He could neither stand up nor walk because of ataxia. The brain MRI showed severe cerebellar atrophy with normal basal ganglia. His EEG and the value of NCV were within normal range, whereas electroretinography showed a notable abnormality, pointing to the extremely small b-wave, resulting in a negative shape of the ERG. Although he was eating sufficiently, the level of serum iron and ferritin remained constantly low. The serum copper level was within normal range, whereas the serum ceruloplasmin level was mildly decreased. A hepatic biopsy indicated no accumulation of copper or iron. This case suggests the importance of the investigation of the serum iron and ceruloplasmin levels in patients who have cerebellar degeneration with psychosis.

Adult↗

PubMed2000

Characterization of fission yeast cohesin: essential anaphase proteolysis of Rad21 phosphorylated in the S phase.

Cohesin complex acts in the formation and maintenance of sister chromatid cohesion during and after S phase. Budding yeast Scc1p/Mcd1p, an essential subunit, is cleaved and dissociates from chromosomes in anaphase, leading to sister chromatid separation. Most cohesin in higher eukaryotes, in contrast, is dissociated from chromosomes well before anaphase. The universal role of cohesin during anaphase thus remains to be determined. We report here initial characterization of four putative cohesin subunits, Psm1, Psm3, Rad21, and Psc3, in fission yeast. They are essential for sister chromatid cohesion. Immunoprecipitation demonstrates stable complex formation of Rad21 with Psm1 and Psm3 but not with Psc3. Chromatin immunoprecipitation shows that cohesin subunits are enriched in broad centromere regions and that the level of centromere-associated Rad21 did not change from metaphase to anaphase, very different from budding yeast. In contrast, Rad21 containing similar cleavage sites to those of Scc1p/Mcd1p is cleaved specifically in anaphase. This cleavage is essential, although the amount of cleaved product is very small (<5%). Mis4, another sister chromatid cohesion protein, plays an essential role for loading Rad21 on chromatin. A simple model is presented to explain the specific behavior of fission yeast cohesin and why only a tiny fraction of Rad21 is sufficient to be cleaved for normal anaphase.

Anaphase↗

PubMed2000

Stimulatory function of gp49A, a murine Ig-like receptor, in rat basophilic leukemia cells.

Murine gp49, a 49-kDa type I transmembrane glycoprotein, is a member of the Ig-like receptors expressed on the surface of cells involved in natural immunity such as mast cells, NK cells, and macrophages. The two major subtypes, gp49A and gp49B, are encoded by two different genes adjacent to each other. gp49B contains an immunoreceptor tyrosine-based inhibitory motif in its cytoplasmic region and is known to function as an inhibitory molecule. In contrast, gp49A does not harbor any specific motif for signal transduction, nor has its physiological role been determined. Here we report on the stimulatory nature of gp49A by analyzing biochemical characteristics of chimeric molecules consisting of an ectodomain of Fc receptor and a C-terminal half of gp49A, namely the pretransmembrane, transmembrane, and cytoplasmic portions, expressed on the rat basophilic leukemia mast cell line. Cross-linking of the chimeric receptors evoked cytoplasmic calcium mobilization, PGD(2) release, and transcription of IL-3 and IL-4 genes, but did not elicit degranulation of the cells. The chimeric molecule could be expressed as a singlet and a homodimeric form on the cell surface. A pretransmembrane cysteine residue of gp49A was necessary for dimer formation. Dimerization was be necessary for their incorporation into glycolipid-enriched membrane fraction (GEM) upon cross-linking stimuli. The calcium mobilization response was inhibited by treatment of cells with methyl-beta-cyclodextrin, an inhibitor of GEM formation. Together with these results, it was strongly suggested that gp49A could be expressed as a homodimer and elicit activation signals that lead to calcium mobilization, eicosanoid production, and cytokine gene transcription through its incorporation into GEM.

Animals↗

PubMed2000

AMP-Activated protein kinase is activated by the stimulations of G(q)-coupled receptors.

The AMP-activated protein kinase (AMPK) functions as a metabolic sensor that monitors cellular AMP and ATP levels. Platelet-activating factor (PAF) activates endogeneous AMPKalpha1 in Chinese hamster ovary cells expressing the PAF receptor coupled with both G(i) and G(q), but its activity was not inhibited after treatment with islet-activating protein. Norepinephrine and bradykinin also activated AMPKalpha1 in cells expressing the G(q)-coupled alpha(1b)-adrenergic receptor and bradykinin receptor, respectively. Stimulations of the G(i)-coupled alpha(2A)-adrenergic receptor, fMet-Leu-Phe receptor, prostaglandin EP3alpha receptor, and G(s)-coupled beta(2)-adrenergic receptor did not activate AMPKalpha1. AMPKalpha1 thus is activated specifically by stimulation of G(q)-coupled receptors. G(q)-coupled receptors transmit the signal for GLUT4 translocation and glucose uptake through an insulin-independent pathway. However, direct activation of AMPKalpha1 with treatment of 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside did not trigger GLUT4 translocation nor stimulate glucose uptake in our cells. Thus, activation of AMPKalpha1 via G(q) is not sufficient to trigger GLUT4 translocation or stimulate glucose uptake.

AMP-Activated Protein Kinases↗

PubMed2000

Fcgamma receptor IIB-deficient mice develop Goodpasture's syndrome upon immunization with type IV collagen: a novel murine model for autoimmune glomerular basement membrane disease.

The combination of hemorrhagic pneumonitis and rapidly progressive glomerulonephritis is a characteristic feature of Goodpasture's syndrome (GPS), an autoimmune disease resulting from the interaction of pathogenic anti-collagen type IV (C-IV) antibodies with alveolar and glomerular basement membranes. Lack of a suitable animal model for this fatal disease has hampered both a basic understanding of its etiology and the development of therapeutic strategies. We now report a novel model for GPS using mice deficient in a central regulatory receptor for immunoglobulin (Ig)G antibody expression and function, the type IIB Fc receptor for IgG (FcgammaRIIB). Mutant mice immunized with bovine C-IV reproducibly develop massive pulmonary hemorrhage with neutrophil and macrophage infiltration and crescentic glomerulonephritis. The distinctive linear, ribbon-like deposition of IgG immune complex seen in GPS was observed along the glomerular and tubulointerstitial membranes of diseased animals. These results highlight the role of FcgammaRIIB in maintaining tolerance and suggest that it may play a role in the pathogenesis of human GPS.

Animals↗

PubMed2000

A novel form of prostate-specific antigen transcript produced by alternative splicing.

Molecular characterization of prostate-specific antigen (PSA) has not been well elucidated, despite a great deal of clinical study. We examined the heterogeneity of PSA using reverse transcription-PCR and direct sequencing. A novel, alternatively spliced variant of the PSA transcript was found in prostate cancer (PC), as well as in benign prostatic tissue. This alternative splicing leads to the deletion of 44 amino acid residues (amino acids 45-88) from mature PSA, resulting in the loss of asparagine 45, which is a binding site for a carbohydrate chain. By these nested reverse transcription-PCR systems, this novel, alternatively spliced PSA gene was recognized in 13 of 18 (72.2%) cases with noncancerous prostate tissue, 4 of 5 (80.0%) PC cases, and 3 of 12 (25.0%) blood samples from PC patients (noncancerous prostate tissue group versus blood sample group, P = 0.011). At present, the biological significance of this alternative splicing remains to be established.

Alternative Splicing↗

PubMed2000

Ventricular remodeling after cardiomyoplasty in heart failure sheep: passive and dynamic effects.

BACKGROUND: Recent reports claim that cardiomyoplasty (CMP) has a girdling effect on the left ventricle, to prevent dilatation and functional deterioration, but the mechanism of its long-term effects on the native heart is not known. We compared the relative role of CMP's active squeezing and passive girdling in chronically failing hearts. METHODS: After induction of stable heart failure (left ventricular ejection fraction = 27% +/- 7%) by staged coronary microembolization, CMP was performed in 11 of 18 sheep. After 8 weeks pacing training of the latissimus dorsi muscle (LDM), cardiac assist was begun with 1:2 synchronous bursts in 6 sheep (d-CMP, n = 6), and the LDM in the passive group (p-CMP, n = 5) remained unstimulated. Four (base line) and 30 weeks after induction of heart failure, the pressure-volume relationship was derived. RESULTS: After 30 weeks in d-CMP the slope (Emax) of the end-systolic pressure-volume relationship increased by 66% +/- 55% (p < 0.05) and external work efficiency by 48% +/- 41% (p < 0.01). In the passive CMP and control groups, slope and external work efficiency were unchanged. Conversely, left ventricular end-diastolic volume decreased (-14% +/- 12%, p < 0.05) in the dynamic CMP group compared with a static course in the passive CMP group (3% +/- 10%, p > 0.05) and an increase (18% +/- 15%, p < 0.05) in controls. CONCLUSIONS: Dynamic CMP improved native heart's contractility and external work efficiency. In addition, whereas passive CMP has simply a girdling effect, dynamic CMP also induces reverse left ventricular chamber remodeling.

Animals↗

PubMed2000

Autosomal recessive juvenile parkinsonism.

Autosomal recessive juvenile parkinsonism (AR-JP) is a hereditary neurodegenerative disorder characterized by levodopa-responsive parkinsonism with onset before age 40 years and a slowly progressive course. Families with this condition have been described predominantly in Japanese population, occasionally under different names including an autosomal recessive early-onset parkinsonism with diurnal fluctuation (AR-EPDF) or a familial form of juvenile parkinsonism. Recently, the causative gene for AR-JP was mapped on chromosome 6q25.2-q27, and subsequently a novel gene 'parkin' was identified by means of positional cloning. In this manuscript, we review the clinical, pathological and genetical aspects of AR-JP. It would not only promise to provide important insights into the molecular mechanisms of selective degeneration of dopaminergic neurons in AR-JP, but also bring insights into the mechanisms of degeneration of these neurons in Parkinson's disease.

Adolescent↗

PubMed2000

New plasma-reduced synthetic media, Fukushima cocktails, for the storage of platelets for transfusion.

BACKGROUND: Donor plasma proteins are associated with non-hemolytic allergic reactions, such as urticaria or laryngeal edema, in platelet-transfusion recipients. Replacement of plasma with synthetic media from platelet concentrates (PCs) is considered to be effective in preventing such reactions. However, platelets preserved in media depleted of less than 10% plasma are reported to have functions inferior to those preserved in plasma. METHODS: Fukushima Cocktails (FCs) contain glycerol (25, 50 or 100mM), sodium acetate, glucose and other components. To test the effect and determine the most suitable concentration of glycerol for platelet preservation, functions of platelets including aggregation, hypotonic shock response and swirling pattern and released biochemicals were measured with platelets preserved in Fukushima Cocktails. The effects of residual plasma on platelet functions were also evaluated. Autologous platelets stored for 3 days in solution containing 50 mM glycerol were transfused into healthy volunteer donors to evaluate their safety and survival. RESULTS: The functions (aggregation and hypotonic shock response) of platelets preserved in Fukushima Cocktails with 10% residual plasma were preserved for 5-7 days as well as plasma controls, whereas platelets stored for 9 days in a medium lacking glycerol became swollen and beta-thromboglobulin and thromboxane B(2) increased. When the residual plasma was more than 5%, platelet functions including aggregation, hypotonic shock response and swirling pattern were well preserved for 7 days. The in vivo platelet survival rates at 24 and 48 h after transfusion of platelets stored for 3 days in Fukushima Cocktail were 77% and 60%, respectively, which were not less than autologous plasma-stored platelets. CONCLUSION: Glycerol at a concentration of around 50 mM has a beneficial effect on platelet preservation for more than 7 days. The results of these experiments indicate that platelets stored in Fukushima Cocktail should be useful clinically.

Blood Platelets↗

PubMed2000

Mis3 with a conserved RNA binding motif is essential for ribosome biogenesis and implicated in the start of cell growth and S phase checkpoint.

BACKGROUND: In normal somatic cell cycle, growth and cell cycle are properly coupled. Although CDK (cyclin-dependent kinase) activity is known to be essential for cell cycle control, the mechanism to ensure the coupling has been little understood. RESULTS: We here show that fission yeast Mis3, a novel evolutionarily highly conserved protein with the RNA-interacting KH motif, is essential for ribosome RNA processing, and implicated in initiating the cell growth. Growth arrest of mis3-224, a temperature sensitive mutant at the restrictive temperature, coincides with the early G2 block in the complete medium or the G1/S block in the release from nitrogen starvation, reflecting coupling of cell growth and division. Genetic interactions indicated that Mis3 shares functions with cell cycle regulators and RNA processing proteins, and is under the control of Dsk1 kinase and PP1 phosphatase. Mis3 is needed for the formation of 18S ribosome RNA, and may hence direct the level of proteins required for the coupling. One such candidate is Mik1 kinase. mis3-224 is sensitive to hydroxyurea, and the level of Mik1 protein increases during replication checkpoint in a manner dependent upon the presence of Mis3 and Cds1. CONCLUSIONS: Mis3 is essential for ribosome biogenesis, supports S phase checkpoint, and is needed for the coupling between growth and cell cycle. Whether Mis3 interacts solely with ribosomal precursor RNA remains to be determined.

Amino Acid Motifs↗

PubMed2000

Various abiotic stresses rapidly activate Arabidopsis MAP kinases ATMPK4 and ATMPK6.

Mitogen-activated protein kinase (MAP kinase, MAPK) cascades play pivotal roles in signal transduction of extracellular stimuli, such as environmental stresses and growth regulators, in various organisms. Arabidopsis thaliana MAP kinases constitute a gene family, but stimulatory signals for each MAP kinase have not been elucidated. Here we show that environmental stresses such as low temperature, low humidity, hyper-osmolarity, touch and wounding induce rapid and transient activation of the Arabidopsis MAP kinases ATMPK4 and ATMPK6. Activation of ATMPK4 and ATMPK6 was associated with tyrosine phosphorylation but not with the amounts of mRNA or protein. Kinetics during activation differ between these two MAP kinases. These results suggest that ATMPK4 and ATMPK6 are involved in distinct signal transduction pathways responding to these environmental stresses.

Abscisic Acid↗

PubMed2000

Potassium-adsorption filter for RBC transfusion: a phase III clinical trial.

BACKGROUND: Within the past 2 years, three cases of cardiac arrest just after rapid transfusion of RBCs preserved for over 7 days after 15-Gy irradiation were found. This severe complication caused transient hyperkalemia. To prevent potassium (K(+)) overload by RBC transfusion at the bedside, a K(+)-adsorption filter made of sodium polystyrene sulfonate was developed. STUDY DESIGN AND METHODS: After in vitro and animal safety and efficacy tests, a Phase III clinical trial was conducted with 65 patients given transfusions via the newly developed filter (filter group) and 37 patients in whom the filter was not used (control group) and transfusions were given at twice the usual flow rate (20 mL/min). RESULTS: More than 85-percent (94.4+/-3.8%) removal of K(+) in RBCs in mannitol-adenine-phosphate (MAP) that had been preserved for more than 14 days or that were used 3 days after 15-Gy irradiation (calculated K(+): 3.8+/-1.3 mEq/bag) was achieved in 82 of 83 bags of MAP RBCs in the filter group, with 79.6 percent removed in the other, even in rapid transfusions. RBC recovery 1 day after transfusion, determined by increments in RBCs, Hb, and Hct, were 24 and 0.4 x 10(4) per microL, 0.7 and 0.3 g per dL, and 1.6 and 0 percent, respectively, in the filter and control groups. No adverse transfusion reactions, such as hypotension, anaphylactoid reactions, or asthma-like attacks, were observed, except for one case of urticaria in the filter group. Mild fever (within 1 degrees C) after transfusion was observed in both groups. Serologic markers of hemolysis rose slightly in both groups, but there was no significant difference between the two groups. CONCLUSION: The newly developed K(+)-adsorption filter is useful, especially in a rapid transfusion setting.

Adenine↗