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Makoto Yamamoto

Publications and source records attributed to Makoto Yamamoto.

14 recordsLinked to original sources
PubMed2005

A ferroelectrically switchable columnar liquid crystal phase with achiral molecules: superstructures and properties of liquid crystalline ureas.

Novel columnar liquid crystalline compounds N,N'-bis(3,4,5-trialkoxylphenyl)ureas 1a-c (R = n-C(8)H(17), n-C(12)H(25), and n-C(16)H(33)) were synthesized, and their phase transitions were measured by differential scanning calorimetery. The superstructures were investigated by X-ray diffraction, polarized light optical microscopy, and IR spectroscopy. The compounds exhibited both rectangular and hexagonal columnar phases in which the urea molecules in each column were stacked in one direction with strong hydrogen bonds. To confirm the ferroelectric switching, optoelectronic experiments were carried out, and the hexagonal columnar phases of 1b and 1c gave a sharp peak of spontaneous polarization in response to an applied triangular wave electric field (0.1-18 Hz). This is the first example of ferroelectrically switchable columnar liquid crystal phases generated by achiral molecules.

Journal Article↗
PubMed2005

Aromatic foldamers with iminodicarbonyl linkers: their structures and optical properties.

[structure: see text] Carboxamides possessing naphthalene rings connected by multiple iminodicarbonyl linkers were synthesized. These molecules forced the naphthalene rings to be placed in the positions facing each other, and they form helical foldamers both in solution and in the crystalline state. Their folding structures were investigated by single-crystal X-ray analysis and (1)H NMR spectroscopy. Their absorption and fluorescence spectra showed a red shift as the number of naphthalene moieties increased. This remarkable change is based on the intramolecular interaction between naphthalene moieties. Helicity of the foldamer can be controlled by the introduction of chiral auxiliaries at imide nitrogen atoms, which results in an observation of induced circular dichroism.

Journal Article↗
PubMed2004

Reaction-phase-selective inter- and intramolecular photochemical reaction of 2-pyridone derivatives.

Phase-selective photochemical reaction of 2-pyridone derivatives was examined. Irradiation of 1 in benzene mainly gave rearrangement products 2. However, intermolecular [4 + 4] photocycloaddition proceeded quantitatively in the solid state, affording photodimers 3. An effective pi-pi stacking and dipole-dipole interaction between two pyridone moieties might play important roles in an effective arrangement of 1 for photodimerization in their crystal structures. [reaction: see text]

Journal Article↗
PubMed2004

Partial involvement of group I metabotropic glutamate receptors in the neurotoxicity of 3-N-oxalyl-L-2,3-diaminopropanoic acid (L-beta-ODAP).

Neurolathyrism is a human motoneuron disease caused by the overconsumption of grass pea (Lathyrus sativus) that contains a toxic non-protein amino acid, 3-N-oxalyl-L-2,3-diaminopropanoic acid (L-beta-ODAP). The preventive activities of various glutamatergic agents from acute neuronal death caused by L-beta-ODAP were studied using rat primary cortical neuron/glia culture. Nearly 80% of the rat primary cortical neurons were killed by 300 microM L-beta-ODAP within 24 h. Though antagonists acting on the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor prevented most of the toxicity, antagonists acting on group I metabotropic glutamatergic receptors (mGluRs), including (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA), (S)-alpha-methyl-4-carboxyphenylglycine (MCPG), and 2-methyl-6-(2-phenylethenyl)pyridine (SIB1893) partially and significantly prevented neuronal death due to L-beta-ODAP. These antagonists, within limited concentrations, did not have any inhibitory effects on the currents through AMPA receptors expressed in Xenopus oocytes. L-beta-ODAP itself did not induce the currents through group I mGluRs expressed in Xenopus oocytes. These results suggest that the neurotoxicity induced by L-beta-ODAP is partially mediated by the activation of group I mGluRs by an indirect mechanisms.

Amino Acids, Diamino↗
PubMed2004

[A case of stage I adenocarcinoma of the lung complicated with inflammatory lesions with an 8-year clinical course before surgery; CT and pathological correlations].

A nodular shadow near left hilum of lung was detected by chest radiography in November 1993 in a 79-year-old woman with hypertension and diabetes. Chest radiography in April 2001 revealed growth of the shadow. Chest CT showed a localized ground-glass opacity in the periphery of the lesion shadow. The resected specimen showed that the nodular shadow was papillary adenocarcinoma and the localized ground-glass opacity indicated the presence of inflammatory lesions. The pathological stage was stage I. Our case was a rare adenocarcinoma complicated with inflammatory changes including a granuloma that appeared 8 years later.

Adenocarcinoma, Papillary↗
PubMed2004

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2002)].

From October 2002 to September 2003, we collected the specimen from 476 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of isolated bacteria to various antibacterial agents and patients' characteristics. Of 584 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 578 strains were examined. The breakdown of the isolated bacteria were: Staphylococcus aureus 77, Streptococcus pneumoniae 103, Haemophilus influenzae 95, Pseudomonas aeruginosa (non-mucoid) 61, P. aeruginosa (mucoid) 23, Klebsiella pneumoniae 36, Moraxella subgenus Branhamella catarrhalis 29, etc. Of 77 S. aureus strains, those with 2 microg/ml or less of MIC of oxacillin (MPIPC) [methicillin-susceptible S. aureus: MSSA] was 34 strains (44.2%) and those with 4 microg/ml or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) was 43 strains (55.8%). Against MSSA, imipenem (IPM) and minocycline (MINO) had the most potent antibacterial activity and inhibited the growth of all the strains at 0.25 microg/ml. Although clindamycin (CLDM) and aminoglycosides also had the potent activity, the resistant strains against those agents were detected. Cefotiam (CTM) inhibited the growth of all the strains at 1 microg/ml without the low sensitive strains. Against MRSA, vancomycin (VCM) showed the most potent activity and inhibited the growth of all the strains at 2 microg/ml. Arbekacin (ABK) also showed the relatively potent activity and inhibited the growth of all the strains at 4 microg/ml. Carbapenems showed the most potent activities against S. pneumoniae and inhibited the growth of all the strains at 0.25-0.5 microg/ml. Cefozopran (CZOP) also had a preferable activity (MIC90: 1 microg/ml) and inhibited the growth of all the strains at 2 microg/ml. In contrast, the resistant strains for cefaclor (CCL), erythromycin (EM), CLDM, and tetracycline (TC) were detected in 50.5%, 76.7%, 50.5%, and 80.6% of all the strains, respectively. Against H. influenzae, LVFX showed the most potent activity and inhibited the growth of 92 of all the strains (96.8%) at 0.063 microg/ml. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and non-mucoid) and inhibited the growth of all the strains at 2 microg/ml. The antibacterial activity of CZOP was good and its MIC90 against mucoid and non-mucoid strains was 8 and 16 microg/ml, respectively. CZOP and cefpirome (CPR) were the most potent against K. pneumoniae with 0.125 microg/ml of MIC90. Also, all the agents generally showed potent activities against M. (B.) catarrhalis and the MIC90 of all drugs were 4 microg/ml or less. The approximately half the number (47.5%) of the patients with respiratory infection were aged 70 years or older. As for the incidence by the diseases, bacterial pneumonia and chronic bronchitis were the highest, being noted in 35.7 and 33.8% of all the patients, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. pneumoniae (22.6%). In contrast, S. aureus (16.6%) and P. aeruginosa (13.7%) were relatively frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from all the patients were H. influenzae (24.5%) and S. pneumoniae (24.2%). In comparison of the isolated bacteria by pretreatment agents, P. aeruginosa was relatively frequently isolated from the patients pretreated with cephems or macrolides and H. influenzae was relatively frequently isolated from the patients pretreated with penicillins.

Anti-Bacterial Agents↗
PubMed2004

[A case of liver metastasis of gastric cancer responding well to TS-1].

We report the case of a 79-year-old female with gastric cancer accompanied by liver metastasis that was successfully treated by TS-1, a novel oral fluoropyrimidine derivative. Abdominal CT scan showed a low-density area in the lateral segment of the liver and lymph node swelling in the right side of the abdominal aorta. One treatment course consisted of 4 weeks of TS-1 administration (100 mg daily) followed by a 2-week break. After 2 courses of this treatment, an abdominal CT scan showed no evidence of liver metastasis and a reduction of lymph nodes metastasis. The serum level of CA19-9 was reduced from 780 U/ml to within a normal range. Grade 1-2 toxicity (nausea and diarrhea) was seen after 2 courses. We conclude that TS-1 may be beneficial in the treatment of the liver metastasis of gastric cancer.

Administration, Oral↗
PubMed2004

[Three successful case reports of advanced gastric cancer with chemotherapy].

We report three successful cases with continuous systemic chemotherapy for advanced gastric cancer. Case 1: A 67-year-old male with gastric cancer. Abdominal CT showed the invasion in the pancreas and as a result, continuous systemic infusion of low-dose cisplatin (CDDP 20 mg/day) and 5-fluorouracil (5-FU 1,000 mg/day) was performed. This infusion chemotherapy, CDDP and 5-FU, was continued for 5 days and discontinued for 25 days. Three months after the chemotherapy, the main tumor was remarkably reduced (downstaging was obtained), and consequently, total gastrectomy was performed. Case 2: A 78-year-old male with gastric cancer and hepatic multiple metastases. Abdominal CT scan before operation did not reveal the hepatic metastasis. In the operation for distal gastrectomy, we found multiple metastases on the surface of the liver. Continuous systemic infusion of low-dose CDDP (20 mg/day) and 5-FU (1,000 mg/day) was performed. This infusion chemotherapy, CDDP and 5-FU, was continued for 5 days and discontinued for 2 days. One month after the chemotherapy, Liver metastases had almost disappeared. Case 3: A 73-year-old male had received a distal gastrectomy based on the diagnosis of gastric cancer. The tumor marker, CA19-9, immediately decreased after the operation, but had increased again. He was treated with a combination chemotherapy of TS-1 and CDDP. The treatment consisted of 4 weeks of TS-1 administration (100 mg daily) followed by a 2-week break. CDDP of 10 mg/day was infused intravenously (day 1-5). Four weeks after the infusion, CA19-9 had returned to almost normal. We conclude that the combination chemotherapy of 5-FU (or TS-1) and CDDP might be an effective treatment for advanced and metastatic gastric cancer.

Aged↗
PubMed2003

Genomics approach to abscisic acid- and gibberellin-responsive genes in rice.

We used an 8987-EST collection to construct a cDNA microarray system with various genomics information (full-length cDNA, expression profile, high accuracy genome sequence, phenotype, genetic map, and physical map) in rice. This array was used as a probe to hybridize target RNAs prepared from normally grown callus of rice and from callus treated for 6 hr or 3 days with the hormones abscisic acid (ABA) or gibberellin (GA). We identified 509 clones, including many clones that had never been annotated as ABA-or GA-responsive. These genes included not only ABA- or GA-responsive genes but also genes responsive to other physiological conditions such as pathogen infection, heat shock, and metal ion stress. Comparison of ABA- and GA-responsive genes revealed antagonistic regulation for these genes by both hormones except for one defense-related gene, thionin. The gene for thionin was up-regulated by both hormone treatments for 3 days. The upstream regions of all the genes that were regulated by both hormones had cis-elements for ABA and GA response. We performed a clustering analysis of genes regulated by both hormones and various expression profiles that showed three notable clusters (seed tissues, low temperature and sugar starvation, and thionin-gene related). A comparison of the cis-elements for hormone response genes between rice and Arabidopsis thaliana, we identified cis-elements for dehydration-stress response or for expression of amylase gene as Arabidopsis gene-specific or rice gene-specific, respectively.

Abscisic Acid↗
PubMed2003

Antisense transcripts with rice full-length cDNAs.

BACKGROUND: Natural antisense transcripts control gene expression through post-transcriptional gene silencing by annealing to the complementary sequence of the sense transcript. Because many genome and mRNA sequences have become available recently, genome-wide searches for sense-antisense transcripts have been reported, but few plant sense-antisense transcript pairs have been studied. The Rice Full-Length cDNA Sequencing Project has enabled computational searching of a large number of plant sense-antisense transcript pairs. RESULTS: We identified sense-antisense transcript pairs from 32,127 full-length rice cDNA sequences produced by this project and public rice mRNA sequences by aligning the cDNA sequences with rice genome sequences. We discovered 687 bidirectional transcript pairs in rice, including sense-antisense transcript pairs. Both sense and antisense strands of 342 pairs (50%) showed homology to at least one expressed sequence tag other than that of the pair. Microarray analysis showed 82 pairs (32%) out of 258 pairs on the microarray were more highly expressed than the median expression intensity of 21,938 rice transcriptional units. Both sense and antisense strands of 594 pairs (86%) had coding potential. CONCLUSIONS: The large number of plant sense-antisense transcript pairs suggests that gene regulation by antisense transcripts occurs in plants and not only in animals. On the basis of our results, experiments should be carried out to analyze the function of plant antisense transcripts.

DNA, Antisense↗
PubMed2003

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (2001)].

From October 2001 to September 2002, we collected the specimen from 370 patients with lower respiratory tract infections in 16 institutions in Japan, and investigated the susceptibilities of the isolated bacteria to various antibacterial agents and antibiotics and patients' characteristics. Of 458 strains that were isolated from specimen (mainly from sputum) and assumed to be bacteria causing in inflammation, 456 strains were investigated. The breakdown of the isolated bacteria were: Staphylococcus aureus 69, Streptococcus pneumoniae 72, Haemophilus influenzae 85, Pseudomonas aeruginosa (non-mucoid) 44, P. aeruginosa (mucoid) 13, Klebsiella pneumoniae 32, Moraxella subgenus Branhamella catarrhalis 32, and others. Of 69 S. aureus strains, those with 4 micrograms/mL or more of MIC of oxacillin (methicillin-resistant S. aureus: MRSA) occupied 43.5%. Vancomycin and arbekacin showed the most potent activities against MRSA as observed in 2000. The frequency of S. pneumoniae exhibiting low sensitivity to penicillin (penicillin-intermediate S. pneumoniae: PISP + penicillin-resistant S. pneumoniae: PRSP) was 59.7% and both rates of PISP and PRSP were the highest after 1992. Carbapenems had strong activities against S. pneumoniae. Especially, panipenem and imipenem inhibited the growth of all 72 strains at 0.125 and 0.5 microgram/mL, respectively. Generally, all drugs had strong activities against H. influenzae with MIC90s of 16 micrograms/mL or less. The drug that had the strongest activity against H. influenzae was levofloxacin, which inhibited the growth of 80 of the 85 strains at 0.063 microgram/mL. Against P. aeruginosa mucoid strain, meropenem had a strong activity with MIC90 of 0.5 microgram/mL while, against non-mucoid strain, tobramycin had a strong activity with MIC90 of 2 micrograms/mL. K. pneumoniae showed good susceptibilities to all drugs except ampicillin and minocycline, and the MIC90s were 4 micrograms/mL or less. Particularly, cefmenoxime, cefpirome, and imipenem had the strongest activity (MIC90: 0.125 microgram/mL), and cefozopran had a strong activity, inhibiting the growth of all strains at 0.25 microgram/mL. Also, all drugs generally had strong activities against M. (B.) catarrhalis. MIC90s of all drugs were 4 micrograms/mL or less. The drug that had the strongest activity was minocycline and levofloxacin inhibiting all 32 strains at 0.063 microgram/mL. Most of the patients with respiratory infection were aged 70 years or older, accounting for approximately a half of the total (40.5%). As for the incidence by the diseases, bacterial pneumonia and chronic bronchitis were the highest, being noted in 39.2% and 37.3% of all the patients, respectively. The bacteria frequently isolated from the patients with bacterial pneumonia were S. aureus (19.3%) and S. pneumoniae (19.9%). In contrast, H. influenzae (22.0%) were frequently isolated from the patients with chronic bronchitis. Before the drug administration, the bacteria frequently isolated from the patients were S. pneumoniae (20.8%) and H. influenzae (21.5%). S. pneumoniae and H. influenzae decreased after the initiation of drug administration while S. aureus increased. The isolation frequency of P. aeruginosa was higher after than before the initiation of drug administration. The bacteria were frequently isolated from the patients who had already treated with cephems were S. aureus and P. aeruginosa. From the patients who had already treated with macrolides, S. pneumoniae was the most frequently isolated while S. aureus was the most frequently isolated from the patients pre-treated with quinolones.

Adult↗
PubMed2002

Novel superstructure of nondiscoid mesogens: uneven-parallel association of half-disk molecules, 3,4,5-trialkoxybenzoic anhydrides, to a columnar structure and its one-directionally geared interdigitation.

Compact and simple nondiscoid mesogens, trialkoxybenzoic anhydrides 2-11 ((RO)(3)C(6)H(2)-CO-O-CO-C(6)H(2)(OR)(3), R = C(2)H(5), n-C(3)H(7), n-C(4)H(9), n-C(6)H(13), n-C(8)H(17), n-C(10)H(21), n-C(12)H(25), n-C(14)H(29), n-C(16)H(33), and (S)- and (R)-3,7-dimethyloctyl) were designed and synthesized, and their superstructures were investigated by polarized light microscopy, differential scanning calorimetry, calculation (MM2 and AM1), circular dichroism spectroscopy, and X-ray diffraction. As the result, in the cases of 5-9 and 11, the half-disk molecules in the liquid crystal phases were self-assembled by the dipole-dipole interaction between their carbonyl groups to a column in which the molecules were piled up in an alternately antiparallel manner, and the columns were interdigitated each other. The observed interdigitations were highly directional in the perpendicular direction to the column axis. In the case of compound 11 which has (S)- or (R)-3,7-dimethyloctyl groups, a helical organization of the molecules in the column was estimated from the peaks in the circular dichroism spectra. This is the first report of a one-directionally interdigitated columnar phase, and these compounds are the first liquid crystalline acid anhydrides. It was demonstrated that a -CO-O-CO- moiety is useful as a polar junction in liquid crystalline compounds.

Journal Article↗