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Biomedical subjects

A Komatsu

Publications and source records attributed to A Komatsu.

At least 19 recordsLinked to original sources
PubMed2003

Presence of functional domains in NADPH-dependent cytosolic 3,5,3'-Triiodo-L-thyronine (T3)-binding protein (p38CTBP) molecule: analyses with deletion mutants.

Functional domains required for NADPH-binding, T(3)-binding, protein dimerization and cytosolic retention were analyzed in NADPH-dependent cytosolic 3,5,3'-triiodothyronine (T(3))-binding protein (p38CTBP) by using the deletion mutants. Wild-type p38CTBP (amino acids; 1-314) and a series of deletion mutants (amino acids; 1-79, 1-128, 1-146, 1-216, 37-314, and 1-145 with 270-314) were bacterially induced. NADPH-dependent T(3)-binding activity was not observed in all mutant p38CTBPs studied, although wild-type p38CTBP showed high-affinity T(3)-binding activity. Wild-type p38CTBP was able to bind a CL-6B column, none of the mutant p38CTBPs showed any binding activity. Pull-down analyses demonstrated that two regions between amino acid 128 and 146, and between 216 and 270, both of which possess helical structures, were required for homodimeric p38CTBP binding. In fluoroscopic studies, GFP-tagged p38CTBP was preferentially observed in cytoplasm. However, C-terminal region-deleted p38CTBP(1-216) was not only observed in cytoplasm, but also in nucleus. These results suggest that 1) multiple regions in p38CTBP molecule are required for T(3)-binding and NADPH binding, 2) two helical structures in p38CTBP molecule may be important in the homodimer formation, and 3) C-terminal region of p38CTBP contains the function to preserve the protein in cytoplasm.

Animals↗
PubMed2001

Cloning and expression of CitPDS1, a gene encoding phytoene desaturase in citrus.

A cDNA clone encoding phytoene desaturase (PDS) was isolated from citrus (Citrus unshiu Marc.). The transcript of the isolated PDS (CitPDS1) was not detected by conventional RNA gel-blot analysis; instead, it was detected by a sensitive reverse transcription-PCR (RT-PCR). The CitPDS1 transcript in the juice sacs/segment epidermis (edible part) was at a low level in the young fruit, and it increased toward maturation like citrus phytoene synthase (CitPSY1). In the peel, in contrast to CitPSY1, the transcript of which was induced toward maturation, the level of the CitPDS1 transcript remained constant after an increase in July, indicating non-coordinate regulation of CitPDS1 and CitPSY1 in the peel.

Amino Acid Sequence↗
PubMed2000

Selective inhibition of cyclooxygenase-2 with antisense oligodeoxynucleotide restricts induction of rat adjuvant-induced arthritis.

The effects of cyclooxygenase (COX)-2 antisense oligodeoxynucleotide (ODN) in induction of adjuvant-induced arthritis were investigated. Female Lewis rats were injected with Mycobacterium butyricum intradermally at the base of tails to induce arthritis. Synthetic 18 mer phosphorothioate ODNs corresponding to the translation initiation site of rat COX-2 mRNA were prepared. The antisense (AS), sense (S), and "scrambled" (Sc) ODNs were intraperitoneally administered. Arthropathy was evaluated with arthritis score, paw edema, and histological examination. Expression of COX-1 and -2 protein and mRNA were examined with immunostaining and reverse-transcription polymerase chain reaction, respectively. COX-2 AS ODN significantly suppressed induction of arthritis in a dose-dependent manner without severe adverse effects, whereas S and Sc ODNs did not show significant inhibitory effects. COX-2 mRNA and protein expression were also suppressed only by COX-2 AS ODN without any alteration of COX-1 expression. These data suggest that selective inhibition of COX-2 with AS ODN may have a therapeutic potency in the treatment of rheumatoid arthritis.

Animals↗
PubMed2000

A tyramine receptor gene mutation causes a defective olfactory behavior in Drosophila melanogaster.

We characterized molecular profiles of a new olfactory mutant line, honoka (hono), which was found among 500 viable P-element insertion lines screened first by 5-bromo-4-chloro-3-indrolyl-beta-D-galactopyranoside (X-gal) staining on the third segment of the antenna, and then by behavioral assays to several pure chemicals. The behavioral responses of hono mutants to repellents such as ethyl acetate (EA), benzaldehyde (BZ) and 4-methylcycrohexanol (MCH), were reduced compared with those of a control strain. The location of the P-element insertion was determined to be about 100bp) upstream of the first exon of the tyramine receptor gene. The level of 3.6kb tyramine receptor mRNA expression was reduced in hono compared with that of wild-type flies. The tyramine receptor cDNA hybridized to the chromosomal division 79C-D, the same locus as the P-element insertion point in hono, and not to 99A-B, previously reported by Arakawa et al. (1990. Neuron 2, 343-354). Electrophysiological responses to octopamine and tyramine were examined by measuring the excitatory junctional potential (EJP) amplitude from larval body-wall muscles of the hono mutant. The hono was impaired with responding to tyramine, while displaying normal response to octopamine. These results indicate that tyramine has a functional role in the Drosophila olfactory system as a neurotransmitter or a neuromodulator, and hono is the first tyramine receptor mutant. This study provides the first step toward understanding of the molecular genetics of tyramine-mediated neural functions in Drosophila.

Acetates↗
PubMed2000

Molecular cloning of a homologue of dad-1 gene in citrus: distinctive expression during fruit development.

A cDNA homologue to the human defender against apoptotic death gene (dad-1), which is involved in programmed cell death, was isolated from satsuma mandarin (Citrus unshiu Marc.) fruit. It (Citdad-1-1) was 345 bp long, with a deduced protein sequence of 115 amino acids. Southern hybridization suggests that dad-1-related sequences are present as a small gene family in the citrus genome. Expression of Citdad-1-1 was progressively down-regulated in leaves as they matured, but not in juice sac/segment epidermis (edible part) towards fruit ripening. The role of dad-1 during citrus development is also discussed.

Amino Acid Sequence↗
PubMed2000

Structure, expression, and conserved physical linkage of mouse testicular cell adhesion molecule-1 (TCAM-1) gene.

Isolation and characterization were performed for cDNA encoding mouse testicular cell adhesion molecule-1 (TCAM-1) using 2908 bases coding for a protein having 548 amino acids (60 kDa). Mouse TCAM-1 protein was found to consist of seven domains for signal sequence, five immunoglobulin (Ig) domains, and the transmembrane plus cytoplasmic domain. TCAM-1 gene and the region linking it to growth hormone (GH) gene located downstream from the TCAM-1 gene were then analyzed. The mouse TCAM-1 gene was 11.6 kb in length with 8 exons; the same as for the 12.0 kb rat gene. The distance from the TCAM-1 to GH gene was 12.5 kb in the mouse genome, and 7.6 kb in the rat. By Northern hybridization, 3.1-kb TCAM-1 mRNA was detected in 17-day testis and would appear present in pachytene spermatocytes and round spermatids.

Amino Acid Sequence↗
PubMed1999

Neural expression of hikaru genki protein during embryonic and larval development of Drosophila melanogaster.

Hikaru genki (HIG) is a putative secreted protein of Drosophila that belongs to immunoglobulin and complement-binding protein superfamilies. Previous studies reported that, during pupal and adult stages, HIG protein is synthesized in subsets of neurons and appears to be secreted to the synaptic clefts of neuron-neuron synapses in the central nervous system (CNS). Here we report the analyses of distribution patterns of HIG protein at embryonic and larval stages. In embryos, HIG was mainly observed in subsets of neurons of the CNS that include pCC interneurons and RP5 motorneurons. At third instar larval stage, this protein was detected in a limited number of cells in the brain and ventral nerve cord. Among them are the motorneurons that extend their axons to make neuromuscular junctions on body wall muscle 8. Immunoelectron microscopy showed that these axonal processes as well as the neuromuscular terminals contain numerous vesicles with HIG staining, suggesting that HIG is in a pathway of secretion at this stage. Some neurosecretory cells were also found to express this protein. These data suggest that HIG functions in the nervous system through most developmental stages and may serve as a secreted signalling molecule to modulate the property of synapses or the physiology of the postsynaptic cells.

Animals↗
PubMed1998

Cloning and expression analysis of vacuolar H+-ATPase 69-kDa catalytic subunit cDNA in citrus (Citrus unshiu marc.)1.

To investigate the mechanism of sugar accumulation in fruit vacuoles, a full length cDNA (CitVATP-A) encoding the vacuolar H+-ATPase 69-kDa catalytic subunit was isolated from a cDNA library constructed from citrus fruit (Citrus unshiu Marc.). A 2304-bp insert of CitVATP-A was coded for a 623 amino acid polypeptide with a predicted molecular mass of 68.68 kDa. The deduced amino acid sequence for CitVATP-A showed a 96.5% homology with the carrot homologue. Genomic Southern blot analysis suggested that CitVATP-A is a low-copy number gene. Northern blot analysis of leaves and fruits during the developing stages showed that the level of expression is high in young leaves and is low in mature leaves, and that it increased in both the edible parts and the peel, during fruit growth and maturity.

Amino Acid Sequence↗
PubMed1997

Genetic dissection of sexual behavior in Drosophila melanogaster.

Mating of Drosophila melanogaster is a sterotypically patterned behavior consisting of a fixed sequence of actions that are primarily under genetic control. Mutations that disrupt specific aspects of mating activities offer a starting point for exploring the molecular machineries underlying sexual behavior. Several genes, identified as causing aberrant sexual behavior when mutated, have been isolated and cloned, providing molecular probes for expression and mosaic analyses that can be used in specifying the cells responsible for the behavior. This review presents current understandings of mating behavior obtained by such molecular and cellular approaches and provides an overview of future directions of research in behavioral genetics.

Animal Nutritional Physiological Phenomena↗
PubMed1997

[Hansen's disease and nephropathy as its sequence].

Nephropathy as the sequences of Hansen's disease before and after the introduction of chemotherapy was compared referring to the report by Hayashi in 1943 and the summary of the autopsy reports from 1978 to 1981 at National Hansen's disease hospital Zenseien. Unlike the high rates of tuberculosis as the cause of death before the introduction of chemotherapy (41.3%) those thereafter decreased to be negligible. On the other hand the comparison of the rates of nephropathy with the same way as that of tuberculosis was impossible since the description about nephropathy by Hayashi was not sufficient to characterize each nephropathy since he included arteriolitis, glomerulonephritis and interstitial nephritis together in the term of nephritis. Death rate due to nephritis among Hansen's disease patients according to Hayashi at that time was 21.2% which was twice as many comparing to that in the other cases. According to the report about the cases of Zenseien those reported to have glomerulonephritis was 37.3% though those were not necessarily listed as the cause of death. Also the nephropathy including fibrinoid angitis with occasional microaneurysmal dilatation of afferent arteries, glomerulitis, sclerosis and stricture of efferent arteries likewise ischemic acute tubular necrosis possibly as the result of these angiopathy seemed to be present. These vascular changes partially resemble to that of microscopic periarteritis nodosa but seems to be common in the smaller arteries. In conclusion, unlike the case of tuberculosis the rate of nephritis including glomerulitis, arteriolitis and interstitial nephritis as Hayashi used as his criteria does not seem to have decreased. Therefore, the critical analysis of the nephropathy especially of that relating to the arteriolitis should be done to obtain the knowledge to suppress its occurrence.

Arteritis↗
PubMed1996

Cloning and molecular analysis of cDNAs encoding three sucrose phosphate synthase isoforms from a citrus fruit (Citrus unshiu Marc.).

Three partial cDNA clones (pSPS1, pSPS2 and pSPS3) encoding sucrose phosphate synthases (SPS) were isolated by Reverse Transcription (RT)-PCR using first-strand cDNA prepared from the leaf or fruit of citrus (Citrus unshiu Marc.). The nucleotide and deduced amino acid sequences of the three clones showed significant similarities to SPS previously isolated in other plants. A full-length, cDNA clone, CitSPS1, was isolated from a fruit (juice sacs and pulp segment) cDNA library using one (pSPS1) of the three partial clones as a probe. The 3539-bp CitSPS1 clone coded for a 1057-amino acid polypeptide with a predicted molecular mass of 117.8 kDa. The amino acid sequence deduced from the CitSPS1 clone showed homology with SPS from maize (55.8% identity) and spinach (74.0% identity). Genomic Southern blot analysis suggested that CitSPS1 clone represents a lowcopy-number gene. RNA blot analysis of leaf, flower and fruit showed that CitSPS1 and pSPS2 were expressed in all organs. However, the levels of expression of CitSPS1 in young leaves, flowers and immature fruits were low, but high in mature leaves, and fruit. pSPS2 transcripts were barely detectable in young leaves and immature fruits, low in mature leaves, and high in flowers and mature fruits. pSPS3 transcripts were only detected in young and in mature leaves.

Amino Acid Sequence↗
PubMed1996

A study of the development of atherosclerosis in childhood and young adults: risk factors and the prevention of progression in Japan and the USA. The Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Research Group.

Coronary heart disease (CHD), one of the prevalent results of atherosclerotic disease, has been a leading cause of death in many Western countries for several decades, and now is the second most prevalent cause of death in Japan. Thus attention must also be paid to atherosclerosis in Japan. While there has been a remarkable reduction in the mortality rate from CHD in some Western countries, an undesirable stabilized mortality rate has recently been reported by the government of Japan. This report emphasises the importance of preventing atherosclerosis at an early stage from the viewpoint of cardiovascular pathology, using evidence from statistical data derived from autopsied cases in Japan and the USA.

Adolescent↗
PubMed1994

On the beta-glucuronidase binding protein (BGBP) of microorganisms. Its purification, the antiserum preparation against that and its localization in leproma and the other infectious lesions shown by immunohistologic method.

Our previous studies suggested that M. leprae (ML) grow in peripheral nerves and lepra cells because ML metabolize hyaluronic acid (HA), and use its component for their growth by the aid of host enzyme combined to the bacilli derived beta-glucuronidase binding protein (BGBP). In this study, therefore, we examined the method to purify BGBP from a mycobacterium HI-75 originally separated from a leproma and cultured by modified Ogawa's medium containing split products of HA (glucuronic acid and N-acetylglucosamine). The distribution of BGBP in leproma and the other lesions consisting of hepatitis B virus infected liver and M. avium-intracellulare infected lung tissue were also immunohistologically examined. As the result, the best method to get BGBP was preparatory electrophoresis in the final step of the purification and not the molecular sieving. The BGBP was actually proven in leproma and the other infected tissues as described, indicating the abilities of these microorganisms to utilize the metabolic machinery of the host with the similar ways to that of ML.

Animals↗
PubMed1993

Purification and characterization of two lectins from the sea cucumber Stichopus japonicus.

Two Ca(2+)-dependent lectins were purified from the sea cucumber Stichopus japonicus by affinity chromatography on lactosyl-Sepharose 4B and ion-exchange chromatography on Q-Sepharose. Their molecular masses were estimated to be 13kDa (SJL-I) and 15 kDa (SJL-II) on SDS-PAGE. SJL-I agglutinated rabbit erythrocytes as well as human A, B, and O-type erythrocytes, but SJL-II agglutinated only rabbit erythrocytes. Hemagglutination by SJL-I was competitively inhibited by N-acetyl-D-galactosamine and galactose-containing carbohydrates. On the other hand, only lactose, melibiose, and raffinose gave weak inhibition of hemagglutination by SJL-II, suggesting that SJL-II may have high specificity for particular complex carbohydrate(s) on the surface of rabbit erythrocytes. SJL-II was activated at ten times lower Ca2+ concentration than SJL-I. Both lectins lost activity in acidic pH, while SJL-I appeared more stable down to pH 4.5.

Amino Acids↗
PubMed1992

[The interaction between neural activity and intracellular pH].

The regulation of intracellular pH (pH(i)) in the nervous system has been vigorously studied using a variety of animal cells in the last decade, through advances in techniques for measuring pH(i) accurately in living cells. These studies have elucidated the mechanisms of pH(i) regulation, such as intracellular buffering and acid transport across the cell membrane, in neurons and glial cells. Following an outline of pH(i) regulation, the interaction between neural activity and acid-base balance is discussed. The dynamic change of pH(i), produced by neural activity, and the effect of pH(i) on the electrical properties of neurons and other excitable cells is emphasized.

Acid-Base Equilibrium↗
PubMed1991

[Gross anatomical study of veins in the orbit].

The aim of this study is to clarify the major route of venous return in the orbit. Minute dissections were performed in 10 adult cadavers (5 males and 5 females) after being fixed in a 10% formalin solution. The superior ophthalmic vein (SOV) and its ascending anastomotic branch were consistently well-developed (the average maximum diameter: 6.2mm and 3.2mm, respectively) and these two veins formed the main venous channel from the orbital contents. The ascending anastomotic branch ran between the optic nerve and the medial rectus just behind the eyeball and joined the SOV. A large number of veins, including the inferior ophthalmic vein, which originated from the inferior contents of the orbit, drained into the ascending anastomotic branch. Arteries and/or nerves did not accompany their respective veins in the orbit, except for the lacrimal and ethmoidal veins. The posterior end of the SOV was severely narrowed lateral to the aponeurosis of the lateral rectus, while being conspicuously dilated just behind the eyeball. The above findings suggested that the dilated portion of SOV may act as a reservoir of the venous return of the orbit.

Adult↗