Biomedical subjects

T Nagase

Publications and source records attributed to T Nagase.

At least 19 recordsLinked to original sources

PubMed2003

Obstacles to modern contraceptive use among married women in southern urban Maldives.

This study aimed to clarify the current state of, and factors associated with, modern contraceptive use among married women in the Maldives. A total of 205 women participated in interviews with structured questionnaires. Four sessions of FGIs were conducted to obtain in-depth information about the problems that they faced in using modern contraceptives. Both modern contraceptive users (MCUs) and those who were not modern contraceptive users (NMCUs) had a good knowledge of, and availability and accessibility to, contraceptives and social support for contraceptive use. NMCUs were more likely to have a husband who disapproved of modern contraceptive practice, to have difficulty communicating with their husband, to be afraid of side effects and to be dissatisfied with sexual sensation when using modern contraceptives. Moreover, NMCUs cited more perceived barriers against the use of modern contraceptives and preferred larger families than MCUs.

Adult↗

PubMed2003

Long-term potentiation and long-term depression in hippocampal CA1 neurons of mice lacking the IP(3) type 1 receptor.

To investigate the role in synaptic plasticity of Ca(2+) released from intracellular Ca(2+) stores, mice lacking the inositol 1,4,5-trisphosphate type 1 receptor were developed and the physiological properties, long-term potentiation, and long-term depression of their hippocampal CA1 neurons were examined. There were no significant differences in basic synaptic functions, such as membrane properties and the input/output relationship, between homozygote mutant and wild-type mice. Enhanced paired-pulse facilitation at interpulse intervals of less than 60 ms and enhanced post-tetanic potentiation were observed in the mutant mice, suggesting that the presynaptic mechanism was altered by the absence of the inositol 1,4,5-trisphosphate type 1 receptor. Long-term potentiation in the field-excitatory postsynaptic potentials induced by tetanus (100 Hz, 1 s) and the excitatory postsynaptic currents induced by paired stimulation in hippocampal CA1 pyramidal neurons under whole-cell clamp conditions were significantly greater in mutant mice than in wild-type mice. Homosynaptic long-term depression of CA1 synaptic responses induced by low-frequency stimulation (1 Hz, 500 pulses) was not significantly different, but heterosynaptic depression of the non-associated pathway induced by tetanus was blocked in the mutant mice. Both long-term potentiation and long-term depression in mutant mice were completely dependent on N-methyl-D-aspartate receptor activity. To rule out the possibility of an effect compensating for the lack of the inositol 1,4,5-trisphosphate type 1 receptor occurring during development, an anti-inositol 1,4,5-trisphosphate type 1 receptor monoclonal antibody that blocks receptor function was diffused into the wild-type cell through a patch pipette, and the effect of acute block of inositol 1,4,5-trisphosphate type 1 receptor on long-term potentiation was examined. Significant enhancement of long-term potentiation was observed compared with after control immunoglobulin G injection, suggesting that developmental redundancy was not responsible for the increase in long-term potentiation amplitude observed in the mutant mouse. The properties of channels that could be involved in long-term potentiation induction were examined using whole-cell recording. N-methyl-D-aspartate currents were significantly larger in mutant mice than in wild-type mice only between holding potentials of -60 and -80 mV. We conclude that inositol 1,4,5-trisphosphate type 1 receptor activity is not essential for the induction of synaptic plasticity in hippocampal CA1 neurons, but appears to negatively regulate long-term potentiation induction by mild modulation of channel activities.

Action Potentials↗

PubMed2001

Prediction of the coding sequences of unidentified human genes. XXII. The complete sequences of 50 new cDNA clones which code for large proteins.

As an extension of human cDNA projects for accumulating sequence information on the coding sequences of unidentified genes, we herein present the entire sequences of 50 cDNA clones, named KIAA1939-KIAA1988. cDNA clones to be entirely sequenced were selected by two approaches based on their protein-coding potentialities prior to sequencing: 10 cDNA clones were chosen because their encoding proteins had a molecular mass larger than 50 kDa in an in vitro transcription/translation system; the remaining 40 cDNA clones were selected because their putative proteins-as determined by analysis of the genomic sequences flanked by both the terminal sequences of cDNAs using the GENSCAN gene prediction program-were larger than 400 amino acid residues. According to the sequence data, the average sizes of the inserts and corresponding open reading frames of cDNA clones analyzed here were 4.6 kb and 1.9 kb (643 amino acid residues), respectively. From the results of homology and motif searches against the public databases, the functional categories of the 31 predicted gene products could be assigned; 25 of these predicted gene products (81%) were classified into proteins relating to cell signaling/communication, nucleic acid management, and cell structure/motility. The expression profiles of the genes were also studied in 10 human tissues, 8 brain regions, spinal cord, fetal brain and fetal liver by reverse transcription-coupled polymerase chain reaction, the products of which were quantified by enzyme-linked immunosorbent assay.

Adult↗

PubMed2001

Identification of three novel non-classical cadherin genes through comprehensive analysis of large cDNAs.

The terminal sequences of long cDNAs from human brains were subjected to an improved method of motif-trap screening. This process resulted in the identification of three novel genes that encode proteins with 27, 27, and six cadherin domains that we denoted as KIAA1773, KIAA1774 and KIAA1775, respectively. Sequence analysis indicated that the products of these genes were non-classical cadherins. KIAA1773 was found to be a mammalian homologue of the Drosophila dachsous gene but the remaining two genes did not have any likely homologues in public databases. Assessment of their expression in rat tissues indicated that these genes are expressed in highly distinct and tissue-specific patterns. Notably, KIAA1775 is expressed almost exclusively in the olfactory bulb in the rat brain. In situ hybridization further showed that KIAA1775 is strongly expressed by the mitral and tufted cells in the main and accessory olfactory bulbs, suggesting that KIAA1775 may be important in the formation and maintenance of neuronal networks, particularly those in the olfactory bulb. This study clearly shows the importance and usefulness of our cDNA project in search for genes encoding large proteins, as this project has allowed us to identify several novel non-classical cadherin genes that have thus far not been detected by conventional methods.

Amino Acid Sequence↗

PubMed2001

Prediction of the coding sequences of unidentified human genes. XXI. The complete sequences of 60 new cDNA clones from brain which code for large proteins.

As an extension of a sequencing project of human cDNA clones which encode large proteins of unidentified genes, we herein present the entire sequences of 60 cDNA clones for the genes named KIAA1879-KIAA1938. The cDNA clones were isolated from size-fractionated cDNA libraries derived from human fetal brain, adult whole brain and amygdala, and their protein-coding sequences were predicted. Thirty-seven cDNA clones entirely sequenced in this study were selected as cDNAs which have coding potentiality by in vitro transcription/translation experiments, and the remaining 23 cDNA clones were chosen by computer-assisted analysis of terminal sequences of cDNAs. The average sizes of the inserts and corresponding open reading frames of cDNA clones analyzed here were 4.5 kb and 2.2 kb (733 amino acid residues), respectively. Sequence analyses against the public databases enabled us to annotate the functions of the predicted products of the 25 genes; 84% of these predicted gene products (21 gene products) were classified into proteins related to cell signaling/communication, nucleic acid management, and cell structure/motility. In addition to the sequence information about these 60 genes, their expression profiles were also studied in some human tissues including brain regions by reverse transcription-coupled polymerase chain reaction, products of which were quantified by enzyme-linked immunosorbent assay.

Adult↗

PubMed2001

A novel mouse beta-defensin, mBD-6, predominantly expressed in skeletal muscle.

Defensins comprise a family of cationic antimicrobial peptides that is characterized by the conserved 6 cysteine residues. They are expressed in the epithelial cells of various organs and are identified as key elements in the host defense system at the mucosal surface. We isolated a novel mouse beta-defensin gene from the bacterial artificial chromosome DNA containing the mouse beta-defensin-3 gene. The full-length cDNA was cloned from skeletal muscle cDNA and called mouse beta-defensin-6 (mBD-6). The predicted peptide conserved the 6-cysteine motif and had 59% amino acid sequence identity with mouse beta-defensin-3 and 59% identity with mouse beta-defensin-4. We demonstrated the expression of mBD-6 in skeletal muscle in addition to the esophagus, tongue, and trachea. In animal models of endotoxemia, mBD-6 expression was also induced in the lung. mBD-6 showed potent antimicrobial activity against Escherichia coli and would play an important role in host defense in the esophagus, airways, and skeletal muscle. mBD-6 is the first reported beta-defensin predominantly expressed in skeletal muscle. This unique tissue specificity suggests some novel physiological roles of this peptide family.

Amino Acid Sequence↗

PubMed2001

Human ABCA1 contains a large amino-terminal extracellular domain homologous to an epitope of Sjögren's Syndrome.

ABCA1 has been suggested to play a key role in cellular lipid release from peripheral cells. In order to study structure-function relationship of this protein, the protein product of a full-length human ABCA1 cDNA was examined for its functions and topological orientation. The electrophoretic mobilities of human ABCA1 expressed in transfected cells increased when treated with N-glycosidase F, suggesting that ABCA1 is highly glycosylated. The ABCA1 was photoaffinity-labeled with ATP and mediated the apoA-I-dependent-release of cholesterol and phospholipid. The influenza hemagglutinin (HA) epitope was introduced into the amino-terminus (N-HA) or between the residues 207 and 208 (207-HA) of the protein. While an antibody against the C-terminus peptide of ABCA1 detected both fusion proteins, an anti-HA antibody did not react with the N-HA fusion protein. Confocal microscopy demonstrated strong cell surface signal with the anti-HA antibody of nonpermeabilized HEK293 cells expressing the 207-HA fusion protein. The results suggested that the signal peptide in the amino-terminal region is cleaved off in its mature form and that the following large hydrophilic region is exposed to outside of cells unlike previously proposed models. We found that this amino-terminal extracellular domain contains a segment homologous to the autoantigen SS-N, an epitope of Sjögren's syndrome, and further identified that ABCA7 codes for the autoantigen SS-N.

ATP Binding Cassette Transporter 1↗

PubMed2001

Prediction of the coding sequences of unidentified human genes. XX. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.

To accumulate information on the coding sequences of unidentified genes, we have carried out a sequencing project of human cDNA clones which encode large proteins. We herein present the entire sequences of 100 cDNA clones of unidentified human genes, named KIAA1776 and KIAA1780-KIAA1878, from size-fractionated cDNA libraries derived from human fetal brain, adult whole brain, hippocampus and amygdala. Most of the cDNA clones to be entirely sequenced were selected as cDNAs which were shown to have coding potentiality by in vitro transcription/translation experiments, and some clones were chosen by using computer-assisted analysis of terminal sequences of cDNAs. Three of these clones (fibrillin2/KIAA1776, MEGF10/KIAA1780 and MEGF11/KIAA1781) were isolated as genes encoding proteins with multiple EGF-like domains by motif-trap screening. The average sizes of the inserts and corresponding open reading frames of eDNA clones analyzed here reached 4.7 kb and 2.4 kb (785 amino acid residues), respectively. From the results of homology and motif searches against the public databases, the functional categories of the predicted gene products of 54 genes were determined; 93% of these predicted gene products (50 gene products) were classified as proteins related to cell signaling/communication, nucleic acid management, or cell structure/motility. To collect additional information on these genes, their expression profiles were also studied in 10 human tissues, 8 brain regions, spinal cord, fetal brain and fetal liver by reverse transcription-coupled polymerase chain reaction, products of which were quantified by enzyme-linked immunosorbent assay.

Adult↗

PubMed2001

Effect of pravastatin on survival in patients with advanced hepatocellular carcinoma. A randomized controlled trial.

Chemotherapy is not effective for hepatocellular carcinoma (HCC). HMG-CoA redutase inhibitors have cytostatic activity for cancer cells, but their clinical usefulness is unknown. To investigate whether pravastatin, a potent HMG-CoA reductase inhibitor, prolongs survival in patients with advanced HCC, this randomized controlled trial was conducted between February 1990 and February 1998 at Osaka University Hospital. 91 consecutive patients <71 years old (mean age 62) with unresectable HCC were enroled in this study. 8 patients were withdrawn because of progressive liver dysfunction; 83 patients were randomized to standard treatment with or without pravastatin. All patients underwent transcatheter arterial embolization (TAE) followed by oral 5-FU 200 mg(-1)d for 2 months. Patients were then randomly assigned to control (n = 42) and pravastatin (n = 41) groups. Pravastatin was administered at a daily dose of 40 mg. The effect of pravastatin on tumour growth was assessed by ultrasonography. Primary endpoint was death due to progression of HCC. The duration of pravastatin administration was 16.5 +/- 9.8 months (mean +/- SD). No patients in either group were lost to follow-up. Median survival was 18 months in the pravastatin group versus 9 months in controls (P = 0.006). The Cox proportional hazards model showed that pravastatin was a significant factor contributing to survival. Pravastatin prolonged the survival of patients with advanced HCC, suggesting its value for adjuvant treatment.

Adult↗

PubMed2001

Redox-sensitive regulation of lox-1 gene expression in vascular endothelium.

Oxidative stress has been implicated in atherosclerosis and its underlying conditions. LOX-1 is a novel endothelial receptor for oxidized low-density lipoprotein which might mediate endothelial dysfunction and subsequent atherogenesis. In the present study, we examined LOX-1 gene regulation by oxidative stress. First, superoxide anions generated by hypoxanthine and xanthine oxidase as well as hydrogen peroxide increased LOX-1 mRNA expression in cultured aortic endothelial cells. Homocysteine, an atherogenic substance believed to exert its effects through oxidative stress, enhanced endothelial LOX-1 gene expression, which was suppressed by N-acetylcysteine. Second, rats receiving angiotensin II for 10 days manifested hypertension and LOX-1 upregulation in aortic endothelium via AT1 receptor. Tempo, a superoxide dismutase mimetic, alleviated LOX-1 augmentation induced by angiotensin II. These results indicated redox-sensitive upregulation of LOX-1 mRNA in both in vitro and in vivo systems, suggesting its potential role in atherosclerosis.

Angiotensin II↗

PubMed2001

Identification of novel transcribed sequences on human chromosome 22 by expressed sequence tag mapping.

To identify sequences on the human genome that are actually transcribed, we mapped expressed sequence tags (ESTs) of long cDNAs ranging from 4 kb to 7 kb along a 33.4-Mb sequence of human chromosome 22, the first human chromosome entirely sequenced. By the EST mapping of 30,683 long cDNAs in silico, 603 cDNA sequences were found to locate on chromosome 22 and classified into 169 clusters. Comparison of the genomic loci of these cDNA sequences with 679 genes already annotated on chromosome 22q revealed that 46 clusters represented newly identified transcribed sequences. To further characterize these sequences, we sequenced 12 cDNAs in their entirety out of 46 clusters. Of these 12 cDNAs, 6 were predicted to include a protein-coding region while the remaining 6 were unlikely to encode proteins. Interestingly, 3 out of the 12 cDNAs had the nucleotide sequences of the opposite strands of the genes previously annotated, which suggested that these genomic regions were transcribed bi-directionally. In addition to these newly identified 12 cDNAs, another 12 cDNAs were entirely sequenced since these cDNAs were likely to contain new information about the predicted protein-coding sequences previously annotated. In the cases of KIAA1670 and KIAA1672, these single cDNA sequences covered two separately annotated transcribed regions. For example, the sequence of a clone for KIAA1670 indicated that the CHKL and CPT1B genes were co-transcribed as a contiguous transcript without making both the protein-coding regions fused. In conclusion, the mapping of ESTs derived from long cDNAs followed by sequencing of the entire cDNAs provided indispensable information for the precise annotation of genes on the genome together with ESTs derived from short cDNAs.

Brain Chemistry↗

PubMed2001

Downregulation of hASH1 is associated with the retinoic acid-induced differentiation of human neuroblastoma cell lines.

BACKGROUND: MASH1, a transcription factor with basic helix-loop-helix domain, has a pivotal function to promote differentiation of neural crest cells into autonomic neurons. PROCEDURE: To investigate the functional significance of human MASH1 (hASH1) in the pathogenesis of neuroblastoma, which is originated from autonomic precursor cells, we studied hASH1 gene expression in primary neuroblastomas and human nueroblastoma cell lines. RESULTS: The follovving results were obtained: (i) hASH1 was expressed in 40 out of 61 (66%) primary neuroblastomas, (ii) hASH1 transcripts were downregulated in several cell lines prior to differentiation induced by all-trans retinoic acid (RA), (iii) a neuroblasotma cell line without expression of endogenous hASH1 did not respond to RA at all, and (iv) the analysis of the hASH1 genomic DNA revealed two possible transcription initiation sites, which may correspond to 3.0 kb and 3.5 kb transcripts. CONCLUSIONS: Our observations suggest that, although hASH1 may not preserve the growth capacity of neuroblastomas, downregulation of hASH1 may be necessary to promote neuronal differentiation of neuroblastoma.

5' Untranslated Regions↗

PubMed2001

Inhibition of beta-lactamases by 6,6-bis(hydroxylmethyl)penicillanate.

beta-Lactamases of classes A and C are the two most prevalent resistant determinants to beta-lactam antibiotics among bacterial pathogens. Both these enzymes pursue different mechanisms for their catalytic processes, highlighted by the fact that the hydrolytic water molecule in each approaches the ester of the intermediary acyl-enzyme species from the opposite ends. 6,6-Bis(hydroxylmethyl)penicillanate was designed as an inhibitor that would impair the approach of the hydrolytic water molecule in either of these enzymes upon formation of the acyl-enzyme species. The design, synthesis, and kinetic evaluation of this inhibitor are disclosed herein.

Enterobacter cloacae↗

PubMed2001

Ectopically localized HNK-1 epitope perturbs migration of the midbrain neural crest cells in Pax6 mutant rat.

Small eye rats, which have a mutation in a gene encoding transcription factor Pax6, exhibit impaired migration of the midbrain neural crest cells, thereby showing severe craniofacial defects. Orthotopic grafting of the midbrain neural crest cells taken from the wild-type into Pax6 mutant embryos has suggested environmental defects along the migratory pathway of the midbrain crest cells. In the present study we found that the HNK-1 carbohydrate epitope was ectopically localized in the frontonasal epithelium of Pax6 mutant embryos. The GlcAT-P gene, encoding an enzyme for the synthesis of the HNK-1 epitope, was also expressed ectopically in the frontonasal epithelium of the mutant. In explant cultures, the migration rate of neural crest cells from the midbrain, but not from the forebrain, was significantly less in HNK-1-coated dishes than in non-coated dishes. These results suggest that the arrested migration of the midbrain crest cells in Pax6 mutant embryos may, at least in part, be due to the inhibitory effect of the HNK-1 epitope ectopically localized in the frontonasal epithelium.

Animals↗

PubMed2001

Association of structural polymorphisms in the human period3 gene with delayed sleep phase syndrome.

Recent progress in biological clock research has facilitated genetic analysis of circadian rhythm sleep disorders, such as delayed sleep phase syndrome (DSPS) and non-24-h sleep-wake syndrome (N-24). We analyzed the human period3 (hPer3) gene, one of the human homologs of the Drosophila clock-gene period (Per), as a possible candidate for rhythm disorder susceptibility. All of the coding exons in the hPer3 gene were screened for polymorphisms by a PCR-based strategy using genomic DNA samples from sleep disorder patients and control subjects. We identified six sequence variations with amino acid changes, of which five were common and predicted four haplotypes of the hPer3 gene. One of the haplotypes was significantly associated with DSPS (Bonferroni's corrected P = 0.037; odds ratio = 7.79; 95% CI 1.59-38.3) in our study population. Our results suggest that structural polymorphisms in the hPer3 gene may be implicated in the pathogenesis of DSPS.

Adolescent↗

PubMed2001

Comparative FISH mapping of human cDNA clones to chromosomes of the musk shrew (Suncus murinus, Insectivora).

Forty-one cDNA clones of human functional genes were newly mapped to chromosomes of the musk shrew (Suncus murinus, Insectivora) by fluorescence in situ hybridization, and a comparative cytogenetic map of 51 genes, including 10 genes reported in our previous study, was constructed between human (HSA) and musk shrew (SMU) chromosomes. In this comparative map, the 51 genes localized to human autosomes, except HSA 8, 16, and 20, were mapped to 15 shrew autosomes, except SMU 4, 16, 17 and 18. Twelve conserved segments were identified between human and shrew chromosomes, and six segments among the musk shrew, human, and mouse. Our results defined the presence of at least one inversion and several interchromosomal rearrangements that occurred during evolution after the two species diverged from a common ancestor. Localization of three major histocompatibility complex (MHC) genes to shrew chromosome 3 suggested that the MHC genes of the musk shrew are located in a cluster on chromosome 3. The cytogenetic map constructed in this study is the first cytogenetic map with many functional genes in insectivore species. This approach provides clues for clarifying the chromosomal evolution in this order.

Animals↗

PubMed2001

[Defensins as a mechanism of host defense and innate immunity].

Antimicrobial peptides, including beta-defensins, are thought to be effective agents against opportunistic infections. In humans, three beta-defensins have been identified. The first human beta-defensin, hBD-1, is predominantly expressed in epithelia of the urogenital tract and has been reported to be constitutive. The second and third human beta-defensins, hBD-2 and hBD-3, were isolated from psoriatic skin and found to be predominantly expressed in skin and respiratory tract. Of note, the hBD-2 gene expression is inducible by various proinflammatory agents such as TNF-alpha, IL-1 beta, IL-8, LPS, bacteria, and yeasts. It has been shown that LPS-induced expression of hBD-2 in human tracheobronchial epithelial cells requires CD14, which may complex with Toll-like receptors (TLRs) to ultimately activate NF-kappa B. In addition, beta-defensins have been recently reported to promote immune responses by recruiting dendritic and T cells. Defensins may play a key role in the mechanism of host defense and innate immunity. These defensins, including hBD-2, might provide a new therapeutic approach to infectious diseases.

Animals↗

PubMed2000

Prediction of the coding sequences of unidentified human genes. XIX. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro.

As an extension of our human cDNA project for accumulating sequence information on the coding sequences of unidentified genes, we here present the entire sequences of 100 cDNA clones of unidentified genes, named KIAA1673-KIAA1772, from three sets of size-fractionated cDNA libraries derived from human adult whole brain, hippocampus, and fetal whole brain. The average sizes of the inserts and corresponding open reading frames of cDNA clones analyzed here were 4.9 kb and 2.7 kb (corresponding to 895 amino acid residues), respectively. By computer-assisted analysis of the deduced amino acid sequences, 44 predicted gene products were classified into five functional categories of proteins relating to cell signaling/communication, nucleic acid management, cell structure/motility, protein management, and metabolism. Furthermore, the expression profiles of the genes were also studied in 10 human tissues, 8 brain regions, spinal cord, fetal brain and fetal liver by reverse-transcription-coupled polymerase chain reaction, the products of which were quantified by enzyme-linked immunosorbent assay.

Amino Acids↗