Search PubMed⌕ Search

Biomedical subjects

T Miyake

Publications and source records attributed to T Miyake.

At least 19 recordsLinked to original sources
PubMed1995

The genetic link between the Chinese bamboo partridge (Bambusicola thoracica) and the chicken and junglefowls of the genus Gallus.

Further comparison of mitochondrial control-region DNA base sequences of 16 avian species belonging to the subfamily Phasianinae revealed the following: (i) Generalized perdicine birds (quails and partridges) are of ancient lineages. Even the closest pair, the common quail (Coturnix coturnix japonica) and the Chinese bamboo partridge (Bambusicola thoracica), maintained only 85.71% identity. (ii) The 12 species of phasianine birds previously and presently studied belonged to three distinct branches. The first branch was made exclusively of members of the genus Gallus, while the second branch was made of pheasants of the genera Phasianus, Chrysolophus, and Syrmaticus. Gallopheasants of the genus Lophura were distant cousins to these pheasants. The great argus (Argusianus argus) and peafowls of the genus Pavo constituted the third branch. The position of peacock-pheasants of the genus Polyplectron in the third branch was similar to that of the genus Lophura in the second branch. Members of the fourth phasianine branch, such as tragopans and monals, were not included in the present study. (iii) The one perdicine species, Bambusicola thoracica, was more closely related to phasianine genera Gallus and Pavo than to members of other perdicine genera. The above might indicate that Bambusicola belong to one-stem perdicine lineage that later splits into two sublineages that yielded phasianine birds, one evolving to Gallus, and the other differentiating toward Pavo and its allies.

Animals↗
PubMed1995

hsk1+, a Schizosaccharomyces pombe gene related to Saccharomyces cerevisiae CDC7, is required for chromosomal replication.

Degenerate oligonucleotide-directed polymerase chain reaction was conducted to clone a possible Schizosaccharomyces pombe homologue [hsk1 for a putative homologue of CDC7 (seven) kinase 1] of Saccharomyces cerevisiae Cdc7 kinase. The cloned cDNA for hsk1+ contains an open reading frame consisting of 507 amino acids with predicted mol. wt of 58,370 that possesses overall amino acid identity of 46% (65% including similar residues) to CDC7. In addition to conserved domains for serine-threonine kinases, the predicted primary structure of Hsk1 contains three 'kinase insert' sequences characteristic to Cdc7 at the positions identical to those of Cdc7. Whereas the length and sequences of the kinase inserts are diverged between the two yeast species, 58% identity (76% including similar residues) is detected within the kinase conserved domains. The hsk1+ gene, which is present as a single copy on the S.pombe chromosome, contains two introns within the coding frame. Disruption of the hsk1+ gene by insertion of the ura4+ gene is lethal to growth. Analysis of the DNA content of germinating spores that contain hsk1 null alleles indicates that DNA replication is inhibited in the mutant. The morphology of these mutant spores after germination indicates abnormal nuclear division in some population of germinating spores, suggesting either that Hsk1 may be required for inhibition of mitosis until completion of S phase or that it may also be involved in proper execution of mitosis. Our results suggest that hsk1+ is a strong candidate for the functional fission yeast homologue of budding yeast CDC7 and that a mechanism through which initiation of chromosomal replication is regulated may be conserved between the two yeast species.

Amino Acid Sequence↗
PubMed1995

Remarkable activity enhancement of thermolysin mutants.

Most attempts to modify the properties of enzymes by amino acid substitution around the active sites have resulted in suppression of the biological activity, suggesting that the structure of natural enzymes should be almost optimized evolutionally to show the highest activity. In contrast, we found an interesting site of a well-known metalloendopeptidase, thermolysin (EC.3.4.24.4), where almost all the amino acid replacement causes a remarkable increase in the hydrolytic activity. Negative correlation between the activity and the thermal stability was observed. The flexibility around the substrate binding site is suggested to be a key to the correlation. Nature may have selected the amino acid at this site, which suppresses the flexibility of the molecule, to get the highest thermal stability at the expense of the activity.

Enzyme Activation↗
PubMed1995

Pituitary adenylate cyclase activating polypeptide (PACAP) stimulates growth hormone release from GH3 cells through type II PACAP receptor.

Effect of pituitary adenylate cyclase activating polypeptide (PACAP) on growth hormone (GH) release from GH3 cells was studied in a dynamic superfusion system. PACAP-38 and PACAP-27 stimulated GH release from superfused GH3 cells. The stimulatory effect of PACAP-38 was comparable to those of vasoactive intestinal polypeptide (VIP) and PACAP-27 at a concentration of 1 nM, but the duration of action was more prolonged in PACAP-38 than in the other two peptides. PACAP(6-38), a selective antagonist of PACAP, as well as a VIP antagonist blunted the GH release induced by PACAP-38 and VIP. An antagonist of GH-releasing factor (GRF) at a concentration of 1 microM, however, did not affect the GH release induced by PACAP-38. These findings suggest that PACAP and VIP stimulate GH release from GH3 cells through type II PACAP receptor but not through the GRF receptors.

Animals↗
PubMed1995

Relationship of microparticles with beta 2-glycoprotein I and P-selectin positivity to anticardiolipin antibodies in immune thrombocytopenic purpura.

We investigated the association of beta 2-glycoprotein I and P-selectin with platelet-derived microparticles in 48 patients with immune thrombocytopenic purpura and 20 normal controls using two-color flow cytometric analysis. In addition, anticardiolipin antibodies were detected by an enzyme-linked immunosorbent assay. Platelet microparticles from the patients showed a higher positivity for beta 2-glycoprotein I than those from the normal controls (23.1 +/- 15.4% vs. 5.3 +/- 3.1%, p < 0.01), but this positivity was not related to the presence of platelet-associated IgG or to the severity of thrombocytopenia. In the 18 patients with more than 20% P-selectin-positive microparticles, beta 2-glycoprotein I positivity was significantly higher than in the 30 patients with less than 20% P-selectin-positive microparticles (37.1 +/- 20.5% vs. 21.5 +/- 17.3%, p < 0.01). In addition, anticardiolipin antibodies were detected in eight patients, and they had a significantly higher level of beta 2-glycoprotein I-positive microparticles than the patients without such antibodies (42.0 +/- 22.9% vs. 22.6 +/- 18.9%, p < 0.05). Our results suggest that anticardiolipin antibodies activate platelets in immune thrombocytopenic purpura and cause the generation of microparticles rich in beta 2-glycoprotein I and P-selectin. These microparticles may then act to regulate coagulation abnormalities in patients with anticardiolipin antibodies.

Adolescent↗
PubMed1995

Endoscopic injection sclerotherapy for esophageal variceal hemorrhage in myeloproliferative disorder: case report.

A 70-year-old woman with myeloproliferative disorder and massive splenomegaly presented with hematemesis. Emergency endoscopy demonstrated bleeding from esophageal varices. Management of variceal hemorrhage by endoscopic injection sclerotherapy, using 5% ethanolamine oleate, was successful. Following the control of variceal bleeding, she was treated with hydroxyurea, a myelosuppressive agent. The spleen size markedly decreased and she was discharged 3 months later. Variceal hemorrhage in myeloproliferative disorder has been reported to be fatal on many occasions, despite different therapeutic approaches, including surgery. In this report, we demonstrated that endoscopic injection sclerotherapy followed by treatment with a myelosuppressive agent was effective in a patient with myeloproliferative disorder and variceal hemorrhage.

Aged↗
PubMed1995

Platelet-derived microparticles may influence the development of atherosclerosis in diabetes mellitus.

We investigated the association between low-density lipoprotein (LDL), triglycerides, and platelet activation in 18 patients with hypertension age 41-64 years and 18 with diabetes mellitus aged 43-70 years. Platelet P-selectin positivity and the microparticle level (indicators of activation) were both significantly higher in the diabetics than in healthy controls (P-selectin: 28.0% +/- 7.5% vs. 7.3% +/- 4.2%, P < 0.001; microparticles: 1900 +/- 966 vs. 526 +/- 158/10(4) platelets, P < 0.01). In contrast, there was no significant increase of either parameter in the patients with hypertension. Plasma microparticle levels were also significantly greater in the diabetics with high LDL levels than in those with low LDL levels (2375 +/- 949 vs. 1519 +/- 796/10(4) platelets, P < 0.05), and in those with high rather than low triglyceride levels (2188 +/- 845 vs. 1492 +/- 783/10(4) platelets, P < 0.05). However, platelet positivity for P-selectin was not significantly different between these two subgroups. Microparticle and P-selectin levels both showed no significant difference between the hypertensive patients with high and low LDL or triglyceride levels. These results suggest that platelet-derived microparticles may participate in the development or progression of atherosclerosis in patients with diabetes mellitus.

Adult↗
PubMed1995

Localization of various forms of the gamma subunit of G protein in neural and nonneural tissues.

For a study of the localization of various forms of the gamma subunit of G proteins, antibodies were raised in rabbits against peptides that corresponded to partial amino acid sequences of bovine gamma 2, gamma 3, gamma 5, and gamma 7. Affinity-purified antibodies against gamma 2, gamma 3, and gamma 5 reacted specifically with gamma 2, gamma 3, and gamma 5, respectively, but the antibody against gamma 7 reacted with gamma 2, gamma 3, and a novel gamma subunit, designated gamma S1, as well as with gamma 7. Because these antibodies reacted with the respective forms of the gamma subunit from rat brain, we investigated the localization of gamma subunits in the rat. gamma 2 and gamma 3 were abundant in all regions in the brain, whereas the concentration of gamma 5 and gamma 7 was relatively low with the single exception being a high concentration of gamma 7 in the striatum. The concentration of gamma 2 was consistently high during ontogenic development in the rat brain, whereas gamma 3 appeared about a week after birth and their concentrations then increased until a month after birth. In tissues other than the brain, gamma 3 was observed only in the pituitary gland, whereas gamma 2, gamma 5, and gamma 7 were found in a variety of tissues. In addition, most tissues contained relatively high concentrations of some other gamma subunit, which was detected with an antibody against a gamma 7-derived peptide and appeared to be gamma S1. Among cloned cells tested, gamma 3 was detected only in PC12 pheochromocytoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1995

Fetal arrhythmias: intrauterine diagnosis, treatment and prognosis.

Fetal echocardiography can provide useful information for the evaluation of fetal arrhythmias. Between 1980 and 1993, 44 fetuses with arrhythmias were diagnosed in utero at 12 and 40 weeks of gestation in Kurume University Hospital. Fetal bradycardia, tachycardia and ectopic beats were revealed in 17, seven and 20 fetuses, respectively, and their clinical features and prognosis were evaluated. In the 17 fetuses with bradycardia, eight were associated with congenital heart defect, and six of these developed to fetal hydrops. Of the 17 fetuses, four died in utero, one was terminated, and six died after birth. The other six cases survived. Three of these had a pacemaker implanted after birth. In the seven fetuses with tachycardia, transplacental anti-arrhythmic drugs were administered in five cases and conversion of the arrhythmia was achieved in four. None of the cases was associated with any congenital heart defect, and none died. Three infants had paroxysmal tachycardia postnatally. In the 20 fetuses with ectopic beats, arrhythmia was observed postnatally in 10, but all of these were resolved within 3 months after birth. Fetal bradycardias carried a poor prognosis in most cases and further studies are required to establish effective treatment. Some cases of fetal tachycardia developed recurrent tachycardia postnatally. Close follow-up of the newborn is therefore necessary.

Arrhythmias, Cardiac↗
PubMed1995

Transient dilatation of the abdominal aorta in an infant with Kawasaki disease associated with thrombocytopenia.

We report on an 8 month old infant with Kawasaki disease associated with giant coronary aneurysms and transient thrombocytopenia. The patient's platelet count decreased to 24,000/mm3 on the 31st day of illness and fibrin degradation product was 5 micrograms/mL. Platelet count increased to the normal level (357,000/mm3) on the 35th day of illness. On the 27th day of illness, dilatation of the distal abdominal aorta adjacent to the bifurcation of the iliac arteries was observed by B-mode and color Doppler ultrasonography. It gradually returned to a normal size by the 45th day of illness. Aspirin administered from the 3rd to the 26th day of illness was replaced with flubioprophen because of liver dysfunction. Although we can not eliminate aspirin allergy as the cause of the transient thrombocytopenia, we think that the thrombocytopenia may have been related to the regression of the abdominal aorta.

Aortic Aneurysm, Abdominal↗
PubMed1995

Significance of cytokines and CD68-positive microparticles in immune thrombocytopenic purpura.

We investigated the significance of cytokines (soluble interleukin-2 receptor, granulocyte-macrophage colony-stimulating factor, interleukin-6, and interferon-gamma) and CD68-positive microparticles in immune thrombocytopenic purpura. Cytokines were measured by enzyme-linked immunosorbent assay and microparticles were detected by flow cytometry. CD68 expression by histiocytic U937 cells incubated with lipopolysaccharide or cytokines was also assessed in a control study. The level of CD68-positive microparticles was significantly higher in the patients with thrombocytopenia than in normal controls (p < 0.01). The soluble interleukin-2 receptor level was also significantly higher in patients than in controls (p < 0.01), but the other cytokines did not show a significant difference. However, patients with severe thrombocytopenia (platelet count > 20,000/microliters) had significantly higher levels of granulocyte-macrophage colony-stimulating factor and interleukin-6 than the controls (p < 0.05). When opsonized platelets were incubated with activated U937 cells, lipopolysaccharide and granulocyte-macrophage colony-stimulating factor caused an increase of CD68-positive microparticles in the supernatant. These results suggest that granulocyte-macrophage colony-stimulating factor is released by activated T cells in immune thrombocytopenic purpura and activates monocyte/macrophage phagocytosis, resulting in an increase of circulating CD68-positive microparticles and enhanced platelet destruction.

Adolescent↗
PubMed1995

Finite element analysis of pathogenesis of osteoarthritis in the first carpometacarpal joint.

Stress distribution in the first carpometacarpal joint was analyzed in 49 cadaveric hands using the finite element method to clarify the pathogenesis of osteoarthritis in the joint. The results of the finite element method analysis were compared with those of the contact pressure distribution in the first carpometacarpal joint of cadaveric specimens using pressure-sensitive film, and with the simple roentgenographical and microradiographical manifestations of spur formation, and with histological findings of osteoarthritis to verify the accuracy of the models of computer simulation models. The comparison of these results showed that osteoarthritic changes of the first carpometacarpal joint were found in areas where stress was concentrated during movement of the joint. The saddle shape of this joint is essentially well-designed for the dispersion of normal stress, however minimal displacement due to instability could easily induce osteoarthritis. Furthermore the shallow trapezial configuration may contribute to the high incidence of osteoarthritis changes. The finite element method helped clarify the relationship between stress patterns and osteoarthritis response.

Computer Simulation↗
PubMed1995

Regeneration of axons in transection of the carp spinal cord.

Axonal regeneration in the central nervous system (CNS) was investigated in the fine structural and histochemical aspects using carp spinal cord, which was completely transected at the level of the dorsal fin. Fusion of the transection region and the regeneration of axons already began to be recognized 26 days after operation by electron microscopy. At 115 days after operation, the rostral and caudal parts of the transected spinal cord were completely connected by the regenerating nervous tissue, which contained numerous axons among the ependymal and glial processes. Horseradish peroxidase (HRP), which was injected in the spinal cord at the portion caudal to the transection site was detected in the cytoplasm of large neurons located in the reticular formation of midbrain. This demonstrates that these long axons were regenerated passing through the ablation gap 151-204 days after operation. These findings indicate that regenerating axons in the carp spinal cord can pass through the glial scar formed in the transected portion, which is considered to be the main obstacle for the prolongation of axons in the mammalian CNS. Many regenerating axons, both unmyelinated and myelinated, were observed being in contact directly with the cell membrane of the ependymal as well as astroglial cells. This indicates that neither ependymal nor glial cells play a role as an obstacle for elongation of axons in the carp spinal cord. Numerous GFAP (glial fibrillary acidic protein) positive intermediate filaments were observed in the cell bodies and cytoplasmic processes of both ependymal cells and astroglia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Detection of soluble interleukin-2 receptor in idiopathic thrombocytopenic purpura].

We measured soluble interleukin-2 receptor (sIL-2 R) in serum samples from 57 patients with idiopathic thrombocytopenic purpura (ITP). The sIL-2 R level was significantly increased in the ITP patients (481.3 +/- 378.5 U/ml) compared with controls (176.2 +/- 66.9 U/ml) (p < 0.001), and was significantly higher in 8 patients positive for hepatitis C virus (HCV) antibody positive (1,140.7 +/- 194.3 U/ml) than in 49 HCV-antibody negative patients (378.9 +/- 278.6 U/ml) (p < 0.0001). There was also a significant difference between the HCV-antibody negative ITP patients and the controls (p < 0.01). Elevated sIL-2 R levels correlated with the CD 4/8 ratio (p < 0.05), but not with the platelet count or the level of platelet-associated IgG. The increase of sIL-2 R in ITP may be related to the immunological abnormalities underlying this disease.

Adult↗
PubMed1995

[A 86-year-old woman with dementia, gait and speech disturbance, and right hemiparesis].

We report a 86-year-old woman who developed dementia, gait disturbance, speech disturbance, and right hemiparesis. The patient was well until March of 1979 when upon wakening up on one morning she noted slurring of her speech and weakness in her left upper and lower extremities. These symptoms cleared up during the next several months, however, she noted weakness in her left leg again in May 1985. In 1988, her posture became stooped and she walked in small steps. In 1990, she developed memory disturbance and difficulty in naming. In March 1993, she developed weakness in her right hand; she was treated with aspirin and amantadine HCl, however, she deteriorated during the next two week period, and was admitted to our hospital on March 27, 1993. On admission, she appeared alert, however, she could not answer verbally to questions; she could only utter unintelligible sounds. Apparently she was markedly demented. Her blood pressure was 170/98 mmHg, and general physical examination was unremarkable. Cranial nerves were grossly normal except for marked non-fluency in her word expression. She could not stand or walk, and apparently her right upper and lower extremities were paralyzed with some contracture. Deep reflexes were normally active without asymmetry. Chaddock sign was positive bilaterally. Sensory examination was difficult. Pertinent laboratory examination included WBC 13,000/microliters, BUN 152mg/dl, creatinine 3.75mg/dl, CRP 20.1mg/dl; a chest X-ray film revealed pneumonic shadow in the upper and the middle right lung fields. Cranial CT scan revealed multiple lacunar infarctions in both basal ganglia and cerebral white matters; periventricular lucency was also noted. She was treated with antibiotics and intravenous fluid. Acid-fast bacilli were recovered from sputum, and she was transferred to another hospital for the treatment of pulmonary tuberculosis. After its treatment she returned to our hospital on July 8, 1993, when her condition was complicated with aspiration pneumonia. On admission, she was semicomatose, and no intelligible words were heard. Right facial paresis of the central type was noted. She was unable to stand or walk, and her right upper and lower extremities were paretic. Deep reflexes were increased with extensor toe sign on the right. She was treated with chemotherapy and intravenous fluid, however, her clinical course was complicated with respiratory as well as urinary tract infections. She developed cardiac as well as renal failure and expired on September 25, 1993.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1995

A novel RING-H2 motif protein downregulated by axotomy: its characteristic localization at the postsynaptic density of axosomatic synapse.

Axonal injury and its repair are common and basic neuropathological processes in the CNS, and are composed of a complex of events in a molecular term. In order to get a comprehensive understanding of these processes, we isolated several known and unknown genes which were up-or downregulated in the facial nucleus after transection of the facial nerve by a subtractive/differential screening. Among them, we focus on one downregulated gene, named Neurodap1, because this gene encodes a novel protein carrying the RING-H2 sequence motif categorized in the zinc finger family. Immunoelectron microscopic analysis revealed that the protein encoded by Neurodap1, Neurodap1, was distributed mainly on the cytoplasmic side of the membranes constituting endoplasmic reticulum and Golgi apparatus, supporting the notion of a previously postulated function of RING-H2 motif proteins, that is, involvement in the protein sorting machinery. More interestingly, Neurodap1 was also bound to the postsynaptic density (PSD) region of axosomatic synapses. This fact suggests that Neurodap1 is associated with a specific system sorting proteins to PSD. Therefore, Neurodap1, a newly identified protein as an axotomy-suppressed gene product, might play a significant role in synaptic communication and plasticity through the control of the formation of PSD for maintaining vital functions of nerve cells.

Amino Acid Sequence↗