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T Kusakabe

Publications and source records attributed to T Kusakabe.

At least 127 records · Page 7Linked to original sources
PubMed1995

Effects of acetylcholine and adrenaline on axoplasmic transport at different regions of mouse superior cervical ganglion cells in culture.

Adrenaline and acetylcholine (ACh) were applied locally at three different positions in cultured superior cervical ganglion cells, i.e., cell body, neurite, and growth cone and the effects on the axoplasmic transport were measured with a video-enhanced microscope. Local ACh application to the cell body, neurite, and growth cone caused the same decreasing effect, but the effects of local adrenaline application were different from each other. Local adrenaline application to the cell body and growth cone caused an increase of axoplasmic transport, but local application at the neurite caused no effect. These data may indicate that there was a lack of beta 2 adrenergic receptors in the neurite. Desensitization of axoplasmic transport was also examined in the SCG neurons. Repetitive adrenaline application to the cell body caused desensitization to the stimulus of adrenaline application.

Acetylcholine↗
PubMed1995

Hydrophobic DNA binding of esperamicin requires conformational distortion of the host DNA.

Evidence is presented that the sequence-specific DNA binding of esperamicin is accompanied by structural distortion of the host DNA that depends on hydrophobic interactions. In the first part of this paper, we describe the effects of conformational freedom of DNA on the DNA-cutting efficiency of esperamicin. If conformational distortion of DNA is significantly required for binding of the drug, then the drug should possess a lower binding/cleaving efficiency for conformationally more restricted DNAs. Our results on model DNAs reveal a substantial decrease in the DNA-cleaving efficiency of esperamicin as the conformational freedom of DNA decrease. In the second part we demonstrate that esperamicin binds to DNA with considerably higher affinity in solutions containing organic solvents. This observation indicates that the required distortion of DNA depends on hydrophobic interactions. Molecular origins of the sequence-specific binding are also discussed on the basis of all available data.

Aminoglycosides↗
PubMed1995

Expression of larval-type muscle actin-encoding genes in the ascidian Halocynthia roretzi.

Temporal and spatial expression of muscle actin (MA)-encoding genes in the Halocynthia roretzi MA (HrMA) cluster was examined by whole-mount in situ hybridization and Northern blot analyses. Expression of these MA was restricted to larval muscle cells. None of the MA from the cluster was expressed in any adult tissues examined, including two different types of adult muscle tissue, body-wall muscle and heart muscle. When Northern hybridization was performed using an HrMA coding region probe under low-stringency conditions, transcripts were detected in body-wall muscle and heart muscle, but not in other adult tissues. In addition, transcripts of different lengths were detected in body-wall muscle and heart muscle. The comparison of amino-acid sequences among ascidian MA indicates that they possess at least two distinct MA isoforms, found in larval muscle and adult body-wall. These suggest that different MA are expressed in each type of ascidian muscle.

Actins↗
PubMed1995

A murine Thy-1.2 reporter vector containing a SV40 origin for rapid cloning and analysis of eukaryotic promoters.

A new vector, pATO, was constructed for rapid cloning and analysis of eukaryotic promoters. When a recombinant pATO, carrying a promoter sequence in its multiple cloning site, was introduced into COS cells, Thy-1.2 protein was produced on the cell surface, and was easily identified by an fluorescein-conjugated anti-Thy-1.2 antibody. The intensity of the fluorescence reflected the strength of the inserted promoter. Since pATO could replicate efficiently in COS cells, the recombinant plasmids recovered from a single COS cell were sufficient to transform Escherichia coli cells. This plasmid is applicable for the rapid and labor saving cloning of promoter elements.

Animals↗
PubMed1995

Silent cortical strokes associated with atrial fibrillation.

To clarify whether silent cortical strokes (SCS) could be a predictor of symptomatic stroke in patients with atrial fibrillation (AF), 72 patients with AF (50 with chronic AF, 22 with paroxysmal AF) were studied. Patients with mitral stenosis, history of myocardial infarction, or dilated cardiomyopathy were excluded from this study. Using cranial magnetic resonance imaging (MRI), the patients were divided into those with SCS (23 patients, Group 1) and those without SCS (49 patients, Group 2). The incidence of symptomatic stroke was then compared between the two groups. Three patients (13%) in Group 1 developed symptomatic brain infarction; this is statistically significant (p < 0.05), compared with the patients in Group 2, none of whom experienced symptomatic stroke. We suggest that SCS is a predictor of symptomatic cerebral infarct in patients with AF. Therefore, it is thought to be important to diagnose SCS using cranial MRI or computed tomography and to keep patients with SCS under close surveillance.

Aged↗
PubMed1995

Coexpression and promoter function in two muscle actin gene complexes of different structural organization in the ascidian Halocynthia roretzi.

During embryogenesis of the ascidian Halocynthia roretzi, 42 unicellular striated muscle cells are formed in the tail of the tadpole larva. Isolation of cDNA clones demonstrated that multiple genes for larval muscle actin are expressed in this process. Among them, at least five muscle actin genes (HrMA2, HrMA4a, HrMA4b, HrMA5, and HrMA6) form a cluster (HrMA2/4 cluster) within about 30 kb of the genome. The 5' flanking sequences of the five actin genes resemble each other. When constructs in which 184 bp of the 5' flanking region of each of these genes fused with lacZ were introduced into fertilized eggs, the reporter gene was expressed in muscle cells of the tailbud embryo, suggesting that the 5' flanking region of each cluster gene has promoter activity. In addition, a pair of muscle actin genes, HrMA1a and HrMA1b (HrMA1 pair), was isolated from a genomic region different from that of the HrMA2/4 cluster. The HrMA1a and HrMA1b are linked in a head-to-head arrangement on opposite strands and share a 340-bp 5' flanking sequence containing two symmetrically located TATA boxes. HrMA1a showed basically the same expression pattern as that of HrMA4a. When constructs in which the shared upstream region of HrMA1 pair fused with lacZ in either direction were microinjected into eggs, the reporter gene was expressed in muscle cells of the larval tail, suggesting a bidirectional promoter that regulates muscle-specific transcription of the HrMA1 pair. The tandem cluster of HrMA2/4 genes and the bidirectional promoter of the HrMA1 pair could expedite utilization of muscle-specific trans-acting factors. The organization of genes in the genome may play an important role in the synthesis of a large amount of actins during the process of rapid differentiation.

Actins↗
PubMed1995

Calcitonin gene-related peptide and substance P in the pharynx and lung of the bullfrog, Rana catesbeiana.

Indirect double immunofluorescence labelling in the pharynx and lung of the bullfrog, Rana catesbeiana, demonstrated the occurrence, distribution, and coexistence of two neuropeptides. In the pharynx, immunoreactive calcitonin gene-related peptide (CGRP) and substance P (SP) were localized in nerve fibers distributed within and just beneath the ciliated epithelium. In the lung, CGRP and SP were localized in nerve fibers in five principal locations: 1) within the smooth muscle layer in the interfaveolar septa; 2) in the luminal thickened edges of the septa; 3) around the pulmonary vasculature; 4) within, and 5) under the ciliated epithelium. Within the smooth muscle layer in the septa, luminal thickened septa, and around blood vessels, almost all fibers showed coexistence of CGRP and SP. Within and just beneath the ciliated epithelium in the thickened septa, all fibers showed coexistence of CGRP and SP. No immunoreactivity for vasoactive intestinal polypeptide, neuropeptide Y, galanin, somatostatin, FMRFamide, and leucine- and methionine-enkephalins was detected in the nerve fibers within the larynx and the lung. Together with our previous data, the present findings suggest that peptidergic mechanisms are involved in the regulation of amphibian respiratory systems throughout their life.

Animals↗
PubMed1995

Distribution of immunoreactive neuropeptides in the pancreas of the bullfrog, Rana catesbeiana, demonstrated by immunofluorescence.

Indirect double immunofluorescence labelling for eight neuropeptides in the pancreas of the bullfrog, Rana catesbeiana, demonstrated the occurrence, distribution, and coexistence of certain neuropeptides in the exocrine and endocrine pancreas. Immunoreactivity of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), FMRFamide (FMRF), and galanin (GAL) was localized in nerve fibers distributed between the acini and around the duct system and vasculature of the exocrine pancreas. In these regions, CGRP-immunoreactive fibers were more numerous than those containing the other five peptides. Almost all SP fibers showed coexistence of SP with CGRP, and about one third of fibers also showed coexistence of SP with VIP, NPY, FMRF, and GAL. In the endocrine pancreas, SP, CGRP, VIP, and GAL were recognized in the nerve fibers around and within the islets of Langerhans, and VIP and GAL fibers were more numerous than SP and CGRP fibers. All CGRP fibers, and about half of the VIP and GAL fibers were immunoreactive for SP. NPY- and FMRF-immunoreactive cells were found at the periphery of the islets. These findings suggest that the exocrine and endocrine pancreatic functions of the bullfrog are under the control of peptidergic innervation.

Animals↗
PubMed1995

Distribution of galanin-immunoreactive nerve fibers in the carotid labyrinth of the bullfrog, Rana catesbeiana: Comparison with substance P-immunoreactive fibers.

Immunoreactivity of galanin (GAL) was detected in the nerve fibers distributed within the intervascular stroma of the bullfrog carotid labyrinth. GAL-immunoreactive fibers are numerous, and some are close to the sinusoidal plexus. Most GAL fibers appear as thin processes with some varicosities. A combination of indirect double immunofluorescence labelling and image processing clearly demonstrated that the distribution pattern of GAL fibers is different from that of SP fibers. This indicates that GAL and SP do not coexist in the same nerve fibers. The role of GAL fibers may be different from that of previously reported neuropeptides (substance P, calcitonin gene-related peptide, vasoactive intestinal polypeptide, neuropeptide Y, and others) as a neuromodulator in controlling vascular tone of the labyrinth.

Animals↗
PubMed1995

Structures of cDNAs encoding the muscle-type and non-muscle-type isozymes of lamprey fructose bisphosphate aldolases and the evolution of aldolase genes.

Nearly full-length cDNA clones for muscle-type and non-muscle-type aldolase mRNAs were cloned from lambda gt10 cDNA libraries constructed from skeletal muscle and liver mRNAs of lamprey (Entosphenus japonicus). The cDNA-M8 has 2,240 bp carrying an open reading frame of 1,089 bp which encodes 362 amino acids without the amino terminal methionine, while the cDNA-L3 is 1,761 bp in length and has an open reading frame of 1,092 bp, which encodes 363 amino acids without the methionine. We designated the cDNA clones M8 and L3 as the muscle-type and non-muscle-type aldolase cDNAs, respectively. The entire amino acid sequences deduced from cDNA-M8 and -L3 show a high degree of identity to one another (76%) and also to vertebrate aldolases A (74-76%), B (68-70%), and C (71-76%) and Drosophila melanogaster aldolases alpha, beta, and gamma (66-67%). Northern blot analyses using the 3'-noncoding sequences of cDNA-M8 and -L3 as hybridization probes indicated that the muscle-type mRNA is expressed mainly in the skeletal muscle, heart muscle, brain, and some other tissues, but probably not in liver, while the non-muscle-type mRNA is expressed mainly in the liver and also in brain and other tissues, except for the heart muscle. Phylogenetic analyses showed that both muscle-type and non-muscle-type aldolases of lamprey resemble one another and might share a common ancestor with vertebrate aldolases A and C, but they are not direct ancestors of vertebrate aldolases.

Amino Acid Sequence↗
PubMed1995

Drosophila melanogaster aldolase: characterization of the isozymes alpha, beta, and gamma generated from a single gene.

Three isozymic forms, alpha, beta, and gamma, of Drosophila melanogaster aldolase are produced from a single gene by alternative usage of the triple exons 4 (4 alpha, 4 beta, and 4 gamma) [Shaw-Lee et al. (1992) J. Biol. Chem. 267, 3959-3967; Kim et al. (1992) Mol. Cell. Biol. 12, 773-783; Kai et al. (1992) J. Biochem. 112,677-688]. The expression plasmids for the respective isozymes were transfected into Escherichia coli cells, and the isozymes alpha and beta were purified to homogeneity by a simple procedure, though isozyme gamma was only partially purified. These isozymes are active towards two substrates, fructose-1,6-bisphosphate (Fru-1,6-P2) and fructose-1-phosphate (Fru-1-P), with a preference for Fru-1,6-P2 over Fru-1-P, but they have different kcat/Km values towards these two substrates; isozyme alpha shows the highest value for Fru-1,6-P2. These isozymes show similarity in optimal pHs, thermal stability, and Km values for both Fru-1,6-P2 and Fru-1-P. They are composed of four identical subunits of 40 kDa, forming a tetramer with a molecular weight of approximately 160 kDa. The three isozymes are different in primary structure only at the carboxyl-terminal region encoded by the respective exon 4. Therefore, this region should be primarily responsible for the distinct characteristics of these isozymes.

Amino Acid Sequence↗
PubMed1995

Cerebral gumma showing linear dural enhancement on magnetic resonance imaging--Case report.

A 51-year-old male presented with a rare cerebral gumma accompanied by abducens nerve paresis and cerebellar infarction. Magnetic resonance (MR) imaging demonstrated a homogeneous enhance mass lesion and adjacent linearly enhanced dura mater. Histological examination of the mass revealed a caseating granuloma. Serological studies were positive for active syphilis. Although linear dural enhancement adjacent to the mass lesion on MR imaging is characteristic of meningioma, this finding is also demonstrated in cerebral gumma. Therefore, cerebral gummas should also be included in the differential diagnosis. Immunological tests for syphilis (serum, cerebrospinal fluid) can confirm the diagnosis.

Abducens Nerve↗
PubMed1995

Peptidergic innervation in the amphibian carotid labyrinth.

The amphibian carotid labyrinth, which corresponds to the mammalian carotid body and carotid sinus, is innervated by nerve fibers containing substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), FMRFamide (FMRF), and somatostatin (SOM). SP, CGRP, VIP, and NPY immunoreactive varicose fibers are more densely distributed in the peripheral portion of the carotid labyrinth than FMRF and SOM fibers. The time of appearance of SP, CGRP, and VIP is different for each. First CGRP fibers, then SP fibers appear at an early stage of larval development, and finally VIP fibres are detected at a later stage of larval development. Most SP fibres show coexistence with CGRP, and some SP fibres which show coexistence with NPY immunoreactivity are assumed to be continuous with those demonstrating VIP immunoreactivity. This indicates the possibility of coexistence of four different peptides in the same nerve fibers within the labyrinth. In various vasculatures of mammals, it has been shown that SP, CGRP, VIP, and NPY have a vasoactive nature in relation to the vascular smooth muscle cells. On this basis, it seems that the target of the peptidergic innervation in the amphibian carotid labyrinth is the smooth muscle cells which are abundantly distributed in the intervascular stroma. Accordingly, the peptidergic innervation may be involved in the vascular regulatory function of the labyrinth, although the possibility that these peptides participate in the chemoreception cannot be ruled out. In addition, the vascular regulatory function of the labyrinth may be modulated by the interaction of multiple neuropeptides.

Amphibians↗
PubMed1995

MR imaging evaluation of the spine with titanium alloy pedicular screw fixation.

We studied the cases of 60 patients who underwent magnetic resonance (MR) imaging evaluation after fixation with the titanium alloy pedicular screw system. Spine stabilization was required in the thoracic and lumbar region for various spinal disorders. The images were evaluated for the spinal and adjacent tissues. These pedicular screw systems were imaged safely and caused no particular clinical problems. The localized signal void artifacts were seen around the implants. This artifact did not interfere with the diagnosis for another disease. The spinal cord and dura mater appeared in midsagittal and in axial images except for regions lying close to the implants. After surgery MR imaging revealed the decompressed or the deformed spinal cord. However, the prognosis of spinal disorder could not be revealed by the intensity grade of MR imaging because of the distortion in the spinal cord.

Adult↗
PubMed1994

Isolation and characterization of cDNA and genomic promoter region for a heat shock protein 30 from Aspergillus nidulans.

A cDNA encoding for a heat shock protein 30 (HSP30) of Aspergillus nidulans and the promoter region of its gene were analyzed for their primary structures. The promoter region had no heat shock element but possessed three inverted repeat sequences. Northern blot hybridization indicated that the expression of the HSP30 gene was high at a normal temperature and was slightly accelerated at elevated temperatures in A. nidulans cells. Although the deduced amino acid sequence of the A. nidulans HSP30 had a domain highly conserved among other small HSPs from different species, it showed a sequence homology of only 42% even in comparison with the most closely related molecular species, Neurospora crassa HSP30. These findings suggest that the present HSP30 belongs to a novel subfamily of low-molecular-weight HSPs.

Amino Acid Sequence↗
PubMed1994

Cloning and sequencing of cDNA coding for Cry j I, a major allergen of Japanese cedar pollen.

cDNA clones coding for Cry j I, a major allergen of the Japanese cedar (Cryptomeria japonica) pollen, have been isolated. Two of the clones were sequenced and found to code for a putative 21-residue signal peptide and a 353-residue mature protein with a derived molecular weight of 38.5 KDa. Five possible N-linked glycosylation sites were found in the sequence. Comparison of the nucleotide sequences of the two clones revealed sixteen nucleotide differences and these led to five amino acid exchanges in the mature allergen, indicating that an isoform of the Cry j I molecule exists. The deduced amino acid sequence of the Cry j I shows 46-48% identities with those of the Amb a I family and Amb a II, the major allergens of short ragweed. These findings should facilitate study of the structure-function relationship between the allergen and the immunocompetent cells.

Allergens↗
PubMed1994

Short upstream sequences associated with the muscle-specific expression of an actin gene in ascidian embryos.

The HrMA4 alpha gene for an embryonic muscle actin of the ascidian Halocynthia roretzi is activated at the gastrula stage in differentiating muscle cells exclusively. The 5' upstream region close to the transcription start site of HrMA4 alpha contains several consensus sequences, which include a TATA box at -30, and E-box at -71, a CArG box at -116, and a cluster of three E-boxes between -150 and -190. When deletion constructs of this region, fused with the bacterial gene for beta-galactosidase (lac-Z), were microinjected into fertilized eggs, the reporter gene was expressed in muscle cells of tailbud embryos. Analyses of the deletion constructs suggested that the 103-bp upstream region is sufficient for the appropriate expression of the gene. However, beta-gal activity was very rarely detectable in the case of 82-bp upstream region and no activity was detected in the case of 72-bp upstream region. Mutations in the proximal E-box sequence did not disturb the muscle-specific expression of the reporter gene. These results suggest that rather short sequences between nucleotides -103 and -72 from the transcription start site are associated with the specific expression of HrMA4 alpha.

Actins↗