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T Hirabayashi

Publications and source records attributed to T Hirabayashi.

At least 73 records · Page 4Linked to original sources
PubMed1992

Isolation and characterization of cDNA clones encoding cdc2 homologues from Oryza sativa: a functional homologue and cognate variants.

Using probes obtained by PCR amplification, we have isolated two cognate rice cDNAs (cdc2Os-1 and cdc2Os-2) encoding structural homologues of the cdc2+/CDC28 (cdc2) protein kinase from a cDNA library prepared from cultured rice cells. Comparison of the deduced amino acid sequences of cdc2Os-1 and cdc2Os-2 showed that they are 83% identical. They are 62% identical to CDC28 of Saccharomyces cerevisiae and much more similar to the yeast and mammalian p34cdc2 kinases than to rice R2, a cdc2-related kinase isolated previously by screening the same rice cDNA library with a different oligonucleotide probe. Southern blot analysis indicated that the three rice clones (cdc2Os-1, cdc2Os-2 and R2) are derived from distinct genes and are each found in a single copy per rice haploid genome. RNA blot analysis revealed that these genes are expressed in proliferating rice cells and in young rice seedlings. cdc2Os-1 could complement a temperature-sensitive yeast mutant of cdc28. However, despite the similarity in structure, both cdc2Os-2 and R2 were unable to complement the same mutant. Thus, the present results demonstrate the presence of structurally related, but functionally distinct cognates of the cdc2 cell cycle kinase in rice.

Amino Acid Sequence↗
PubMed1992

Expression pattern of skeletal muscle troponin T isoforms is fixed in cell lineage.

The expression of fast-muscle-type troponin T isoforms in chicken skeletal muscles was studied by two-dimensional SDS-polyacrylamide gel electrophoresis and immunoblotting. According to the pattern of troponin T isoform expression, chicken fast muscle was classified into two groups: One group expressed breast-fast-muscle-type troponin T in addition to leg-fast-muscle-type troponin T, the other expressed only leg-fast-muscle-type troponin T. To the former group belong breast and wing fast muscles and some of the back fast muscles, and to the latter group belong the fast muscles in leg, abdomen, and neck. Transplantation of breast muscle into leg was performed in order to change the physical environment and to investigate the mechanism of isoform expression. Histological observation of the transplant revealed severe degeneration of muscle cells, followed by differentiation of myoblasts in which breast-muscle-type troponin T was eventually expressed. The results showed that the pattern of troponin T isoform expression is primarily fixed in the cell lineage, although nerves modulate it.

Animals↗
PubMed1992

Accumulation of crystallin in developing chicken lens.

Separation and quantitation of crystallin subunits in embryonic and post-hatched chicken lens were carried out by two-dimensional gel electrophoresis and an image analysing system in order to elucidate detail in the accumulation process of each crystallin subunit in lens differentiation. Complete separation of the subunits was possible when 7 M urea was included in the second dimension gel of the electrophoresis. In particular, beta-crystallin could be separated into more than 24 spots on the gel. These experiments showed that delta-crystallin accumulated rapidly during early development up to more than 80% of total crystallins, while beta-crystallin accumulated quickly only after hatching. In contrast with the contents of beta- and delta-crystallins, alpha-crystallin content in total crystallins was kept at approximately 18% throughout lens development. Therefore, it was concluded that crystallins accumulated in several different ways. This suggests that different regulation mechanisms work on the accumulation of each crystallin subunit and that the subunit composition of lens proteins is specific to each state of lens development.

Animals↗
PubMed1992

Cytoskeletal architecture of the matrix cell and neuroblast in the neural tube of the chick embryo.

Cytoskeletal architecture of the matrix cell and neuroblast in the wall of midbrain of 4-6 day-old chick embryos was examined by electron microscopy and immunohistochemistry. The matrix cell, the undifferentiated stem cell later producing neurons and glial cells in the central nervous system, is characterized ultrastructurally by abundant free ribosomes and a poorly developed cytomembrane system. A few microtubules running in random directions are observed in the matrix cell body. In the cell processes, microtubules are oriented longitudinally, and linked with each other by cross-bridges, presumably composed of microtubule-associated proteins (MAPs). The cell processes contain abundant cytoplasmic filaments including a large amount of actin filaments which adhere to the plasma membrane of junctional complexes located immediately below the inner surface of the neural tube. In the neuroblast which has been differentiated from the matrix cell, the cytomembranous organelles, especially rough endoplasmic reticulum are markedly better developed than in the matrix cell; microtubules are more numerous in the cell body. The cell process contains many microtubules with cross-bridges and a few intermediate filaments, which are relatively characteristic of the cytoskeleton of the neuroblast. Phalloidin-staining and immunohistochemistry showed that the neuroblast was richer in F-actin, beta-tubulin, MAP1, MAP2, tau, calspectin, and synapsin I than the matrix cell. As the matrix cell differentiates into the neuroblast, both the cytoskeletal and cytomembranous systems proved to develop features, characteristic of a neuron.

Animals↗
PubMed1991

Identification and distribution of tropomyosin isoforms in chicken digestive canal.

Two-dimensional gel electrophoresis of eight digestive organ extracts from 60-day-old chicks was performed. Judging from the similarity of their protein maps, the organs were classified into the following four types: 1) esophagus type, 2) proventriculus type, 3) gizzard type, and 4) intestine type. In four representative organs of these types, the distribution of tropomyosin isoforms was examined, and four high- and five low-Mr-type isoforms in addition to alpha and beta isoforms were detected in the embryonic organs. In the adult organs, however, there were three high- and four low-Mr-type isoforms, which were restricted to the mucous membrane, in addition to alpha and beta isoforms. Immunoblot analysis indicated that the high- and low-Mr-type isoforms in the embryo corresponded with those in the adult mucous membrane, but differences in the number and amount of the isoforms were found between the embryo and the adult mucous membrane.

Animals↗
PubMed1991

[Study on the stereo-architectural changes in human placental villi of toxemia of pregnancy].

Architectural changes in placental villi in clinical types of toxemia of pregnancy which were divided into four groups according to the main maternal symptoms (hypertension: H type, proteinuria: P type, PH type and IUFD) were studied by scanning electron microscopy and computerized image analysis of serial paraffin step sections. Furthermore plastic casts of villous capillaries were compared and changes in endothelial cells of villous capillaries were observed by transmission electron microscopy. 1) Scanning electron microscopy showed characteristic differences between P type cases and H type cases. Terminal villi were markedly reduced in number and showed few branches especially in P type cases, whereas in H type cases slender terminal villi were observed. The surface structure showed rough degenerative microvilli in H type cases and slender long microvilli in P type cases. 2) Average diameters of terminal branches estimated by image analysis were as follows: Normal cases: 24.8 mu, P type: 23.1 mu, H type: 17.9 mu, PH type: 17.7 mu, IUFD: 13.8 mu. The reduction in the number of intermediate villi in cases of toxemia of pregnancy was about 58% of that of normal cases. 3) Plastic casts of villous capillaries emphasized these changes in each type. 4) Swelling of the endothelial cell into the capillary lumen was observed and an increase in the number of filamentous structures in the cytoplasm of endothelial cells was detected by transmission electron microscopy.

Capillaries↗
PubMed1991

[A study on the relationship between spontaneous contrast echoes in left atrium and cerebral embolism in patients with chronic atrial fibrillation by using transesophageal echocardiography].

We assessed the relationship between the presence of spontaneous eotrast echoes (SCEs) in left atrium (LA) and the incidence of cerebral embolism. Transesophageal echocardiography (TEE) was performed in 56 patients (36 male, age 69.6 +/- 8.9 yrs.) with non-valvular chronic atrial fibrillation (NVAF), In 37 patients (66.1%), SCEs were detected by TEE, However, SCEs could not be detected in any patients by transthoracic echocardiography (TTE). In 9 patients (16.1%), left atrial thrombi were detected by TEE, but they could not be detected by TTE. According to the degree of SCEs, the patients were divided into three groups as follows; Group (-) (n = 19): SCEs were not detectable, Group (mild) (n = 17): SCEs were detectable in part of LA, Group (marked) (n = 20): SCEs were detectable in whole LA. LA thrombi were detected in 1 (5%) of the Group (-) patients, 2 (12%) of the Group (mild) patients and 6 (30%) of the Group (marked) patients (p = NS). 17 patients had a history of cerebral embolism. In Group (-), only one patient (5%) had a history of cerebral embolism. But 4 patients (24%) of Group (mild) and 12 patients (60%) of Group (marked) had histories of cerebral embolism. The incidence of cerebral embolism was significantly higher in Group (marked) than Group (-) (P less than 0.01) and Group (mild) (P less than 0.05). We conclude that, in patients with NVAF, the presence of SCEs by TEE may be a useful variable in identifying increased risk of cerebral embolism.

Aged↗
PubMed1990

Coordinate and discoordinate accumulation of protein constituents in chicken breast muscle.

Accumulation of protein constituents in developing chicken breast muscle was examined by two-dimensional gel electrophoresis. Quantitative analysis of the two-dimensional gels showed a moderate coordination in accumulation among contractile proteins (actin, tropomyosin and myosin light chains) during postnatal development in spite of their isoform transition. Creatine kinase was also accumulated coordinately with contractile proteins during development. In contrast, accumulation kinetics of glycolytic enzymes (glyceraldehyde-3-phosphate dehydrogenase, aldolase and enolase) showed discoordination with those of contractile proteins. These findings suggest that there are two distinct phases in muscle maturation: (1) structural maturation and (2) metabolic maturation.

Animals↗
PubMed1990

Characterization of C-protein isoforms expressed in developing, denervated, and dystrophic chicken skeletal muscles by two-dimensional gel electrophoresis.

C-Proteins in developing, denervated, and dystrophic chicken skeletal muscles were examined by means of two-dimensional (2D) gel electrophoresis in combination with immunoblotting. In this analysis, the electrophoresis system which was devised by Hirabayashi (Anal. Biochem. 117, 443-451, 1981) provided excellent resolution; three C-protein variants, one fast-type (Cf) and two slow-types (CS3 and CS4) with different Mrs and pIs, were distinguished on a 2D gel. In the neonatal breast muscle, both Cf and CS3 were detected, but during postnatal development, CS3 disappeared from this muscle and Cf became only the C-protein isoform in the adult muscle. In posterior latissimus dorsi (PLD) muscle, both Cf and CS3 were similarly detected at the neonatal stage, but CS3 was replaced by CS4 as this muscle developed. When the breast and PLD muscles were denervated or suffered from muscular dystrophy, both CS3 and CS4 were co-expressed in these muscles in addition to Cf. These results definitely show that the C-protein isoform pattern varies during development and degeneration of chicken skeletal muscles, and in addition the dystrophic or denervated muscle differs from the neonatal muscle with regard to C-protein isoform expression. We suggest that chicken skeletal muscle degenerating due to denervation or muscular dystrophy does not simply recapture the nature of the neonatal muscle, but shifts in a somewhat different direction.

Aging↗
PubMed1990

Tissue specificity of tropomyosin from the crayfish, Cambarus clarki.

The molecular heterogeneity and tissue specificity of crustacean tropomyosin were investigated, using muscle and nonmuscle tissues from the crayfish, Cambarus clarki. In muscle, three types of tropomyosin isoforms were found on two-dimensional gel electrophoresis. One of them was specific to cardiac muscle, and the other two were shared by skeletal and visceral muscles. In nonmuscle tissues, four types of isoforms were found on two-dimensional gel electrophoresis and in immunoreplica tests using an antiserum against crayfish skeletal muscle tropomyosin. Two of them were common to the muscle isoforms, but the other two were not detected in muscles. Furthermore, nonmuscle tissues contained several peculiar isoforms, the electrophoretic mobilities of which were considerably higher than those of the other isoforms mentioned above. When tropomyosin was purified from the mid-gut gland, these isoforms with high mobilities were found in the crude tropomyosin preparation. These results showed that the crayfish tropomyosin was heterogeneous and that the isoforms were distributed in a tissue-specific manner, like vertebrate tropomyosin. However, the results did not coincide with those of our previous study on horseshoe crab tropomyosin, which showed molecular heterogeneity but no tissue specificity. In view of the difference in the isoform distributions between the two major groups (Crustacea and Merostomata) of Arthropoda, the significance of the tissue specificity of tropomyosin isoforms was discussed.

Animals↗
PubMed1990

Effect of phosphate depletion on vasopressin secretion and kidney tissue vasopressin concentration in rats.

The effects of chronic phosphate depletion on vasopressin (ADH) secretion and kidney tissue ADH concentration were examined in rats fed on a diet containing 0.26% phosphorus (LP) or 0.99% phosphorus (NP). The concentration of plasma phosphorus (P) fell significantly in the LP rats after a 4-week period on the experimental diet. There was no significant difference between the LP and NP rats as regards their plasma ADH concentrations and kidney tissue ADH concentrations in normal hydration after a 4-week period on the experimental diets. Following hypertonic saline tests, the plasma ADH concentrations increased significantly in the LP and NP rats, but there was no significant difference between the groups. The kidney medulla and papilla ADH concentrations increased significantly with plasma ADH elevations in both groups. Again, no difference could be found in the cortico-medullary ADH concentration gradients between the two groups. These results indicate that chronic hypophosphatemia in phosphate depleted rats may not be related to ADH secretion and the distribution or tissue concentration of ADH in the kidney. Further, our data suggest that a low plasma P does not influence the ability of ADH to bind to kidney receptor in rats.

Animals↗
PubMed1990

[Pharmacokinetics of aztreonam on hemodialysis].

We studied the pharmacokinetics of aztreonam (AZT) in 6 patients with renal insufficiencies during nonhemodialysis and hemodialysis. After intravenous injection of 1 g AZT, it was found that serum AZT concentrations during hemodialysis were different from those during nonhemodialysis and serum half-lives (T 1/2 beta) were 3.44 hours and 16.97 hours, respectively. AZT clearance changed from 0.762 L/hr during hemodialysis to 3.360 L/hr during nonhemodialysis. These findings suggest that hemodialysis patients should receive the standard dose of AZT as a loading dose, followed by one-half the loading dose per day and receive a supplemental dose equal to half their usual maintenance dose after each dialysis session.

Aged↗
PubMed1989

Detection of dystrophin on two-dimensional gel electrophoresis.

A protein with MW approximately 350 k daltons and pI approximately 5.5, which was deleted in the dystrophic mouse (C57BL/10ScSn-mdx), was detected on two-dimensional gel electrophoresis with silver staining. Deletion of this protein was uniformly observed in the dystrophic mouse extensor digitus longus, soleus and cardiac muscle. This protein specifically reacted with the monoclonal antibody against the chemically synthesized N-terminal fragment of human dystrophin. The protein reacting with this monoclonal antibody was also detected in rabbit back-muscle, rat extensor digitus longus and human skeletal muscle at the same position as the mouse muscle protein, on the two-dimensional gel electrophoresis. Our results show that dystrophin is solubilized in 8M guanidine HCl and that the modified two-dimensional gel electrophoresis can be applied to separate dystrophin.

Animals↗
PubMed1989

Coordinate accumulation of troponin subunits in chicken breast muscle.

The accumulation of troponin subunits in developing chicken breast muscle was determined by two-dimensional gel electrophoresis and an image analyzing system. Many troponin T isoforms, including those hidden behind creatine kinase, were detected on the two-dimensional pattern by the addition of 6 M urea in the second dimension. These troponin T isoforms were classified into four types by developmental order, isoelectric point, and molecular weight: leg-muscle type (L), neonatal breast-muscle type (BN), young chicken breast-muscle type (BC), and adult breast-muscle type (BA). The L-, BN-, and BC-type troponin Ts were transiently expressed at specific developmental stages. Quantitative analysis of two-dimensional patterns of troponin subunits including troponin I and troponin C showed moderate coordination in accumulation among the three subunits throughout postnatal development, when the total amount of all isoforms of troponin T was taken into account.

Animals↗
PubMed1989

Comparison of protein constituents between atria and ventricles from various vertebrates by two-dimensional gel electrophoresis.

1. Protein constituents of cardiac muscles of 23 species were examined by two-dimensional gel electrophoresis in order to find the difference in protein components between atria and ventricles. 2. Protein compositions of atria were similar to those of ventricles, however, differences were found in myosin and some other proteins in most species. 3. A major protein with molecular weights of 12,000-15,000 daltons was distributed only in atria from mammals. 4. The atrioventricular difference suggested that the ventricular tissue was more specialized in mammals than in birds, as compared with the atrial tissue.

Actins↗
PubMed1989

Tropomyosin isoforms in developing chicken gizzard smooth muscle.

In the embryonic smooth muscle of chicken gizzards we found 4 high-Mr-type and 5 low-Mr-type tropomyosin isoforms in addition to alpha- and beta-isoforms reported already. The criteria by which they were identified as tropomyosin isoforms were as follows: 1) anomalous reduction of electrophoretic mobility in the presence of urea, 2) cross reactivity with antisera against tropomyosins, 3) inclusion in a tropomyosin preparation obtained by the usual method for tropomyosin purification, and 4) binding ability to skeletal muscle actin. At the early stages of development, the amounts of these isoforms were larger than those of alpha- and beta-isoforms, but they gradually decreased at later stages and finally disappeared completely after hatching. Our previous study of gizzard smooth muscle showed that the amount ratio of accumulated tropomyosin to gamma-actin was reasonably constant in the development after hatching, while, at the earlier embryonic stages (7-14 d of incubation), it was lower than expected. The isoforms found in this study were present in amounts large enough to bring the ratio at the earlier stages up to the constant amount ratio observed after hatching. Therefore, the coordinate accumulation of actin and tropomyosin was suggested to occur even at the embryonic stages.

Actins↗