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Biomedical subjects

Akira Murakami

Publications and source records attributed to Akira Murakami.

At least 91 records · Page 5Linked to original sources
PubMed2004

Suppressive effects of natural and synthetic agents on dextran sulfate sodium-induced interleukin-1beta release from murine peritoneal macrophages.

Interleukin (IL)-1beta, an anti-apoptotic and pro-inflammatory cytokine, plays an important role in the onset of inflammation-associated disease. We examined the suppressive effects of a total of 39 synthetic or natural compounds on dextran sulfate sodium-induced IL-1beta production in murine peritoneal macrophages. Several compounds, including alpha-tocopherol, gallic acid, (-)-catechin and rutin, were found to be highly effective for attenuating IL-1beta production, suggesting that they would be useful for anti-inflammatory application.

Animals↗
PubMed2004

[Histopathologic study on cyclocryotherapy of human and monkey eyes].

PURPOSE: To evaluate the lesion and repair process of the ciliary body and adjacent tissues in glaucomatous human eyes and normal monkey eyes with cyclocryotherapy. METHODS: We used light and electron microscopy to observe the ciliary body and adjacent tissues in five glaucomatous human eyes and five normal monkey eyes which were given cyclocryotherapy. RESULTS: Five absolute glaucomatous eyes were given cyclocryotherapy from one and a half to 3 years before the enucleation. One eye had no coagulated spots on the ciliary process, but five eyes had coagulated spots on the pars plana. The pigment epithelial cells were atrophic or had disappeared, but non-pigment epithelial cells had proliferated by one or two layers. At the lesion of monkey pars plicata cyclocryotherapy up to three months, melanophage phagocytosed pigment epithelium and melanocytes accumulated, although the proliferation of non-pigment epithelial cells was seen. At the lesion of monkey pars plana cyclocryotherapy melanophage accumulation was also marked, although non-pigment epithelial proliferation was greater than in pars plicata cyclocryotherapy. CONCLUSION: As cyclocryotherapy is a blind therapy, it is uncertain and difficult to destroy the ciliary process precisely. The repair process continued up to three months after monkey cyclocryotherapy, but it took up to one year and 6 months after human cyclocryotherapy.

Adult↗
PubMed2004

[Clinicopathological study on suprachoroidal and supraciliary hemorrhage during enucleation].

PURPOSE: To investigate the pathogenesis of suprachoroidal and supraciliary hemorrhage that might have been induced during enucleation. METHODS: A histopathological examination of 392 enucleated eyeballs was carried out and 8 eyeballs with suprachoroidal and supraciliary hemorrhage were selected for further clinicopathological examination. RESULTS: Among 14 eyeballs with severe acute intraocular inflammation, 7 eyeballs with suprachoroidal and supraciliary hemorrhage were found and one other such eyeball was seen among 53 with neovascular glaucoma. Among these 8, there was one case of prolapse of intraocular tissue with severe hemorrhage into the suprachoroidal and supraciliary spaces; 4 cases of severe hemorrhage into the suprachoroidal and supraciliary spaces without prolapse of intraocular tissue; and 3 cases of mild hemorrhage into the suprachoroidal or supraciliary spaces. CONCLUSIONS: In the eyeballs with severe acute intraocular inflammation, intraocular pressure was elevated and the blood vessels were weakened by inflammatory cell infiltration. During enucleation external forces affected the blood vessel wall of the ciliary arteries and vortex veins, and the breakdown of vessel walls might have been the cause of the suprachoroidal and supraciliary hemorrhage.

Acute Disease↗
PubMed2004

[Case of late onset and isolated lattice corneal dystrophy with Asn544Ser (N544S) mutation of transforming growth factor beta-induced (TGFBI, BIGH3) gene].

PURPOSE: To report a case of lattice corneal dystrophy (LCD) with Asn544Ser (N544S) mutation of the transforming growth factor beta-induced (TGFBI) gene. CASE: A 68-year-old male patient with late-onset, sporadic LCD without corneal erosion. Amyloid deposits showing dot and lattice lines were seen in the mid to deep stroma. After obtaining appropriate informed consent, genomic DNA was amplified by polymerase chain reaction (PCR) and directly sequenced. RESULTS: A heterozygous single base pair transition (AAT --> AGT), resulting in substitution of serine for asparagine at codon 544 of the TGFBI gene, was detected. CONCLUSION: The case was classified as atypical type IV because of the late onset, lack of corneal erosion, and amyloid deposits in the mid to deep stroma.

Aged↗
PubMed2003

Structure-activity relationship of benzo[b]thiophene-2-sulfonamide derivatives as novel human chymase inhibitors.

We have identified a new class of chymase inhibitor through a substituent analysis of MWP00965, which we previously discovered by in silico screening. TY-51076 (7) showed high potency (IC(50)=56 nM) and excellent selectivity for chymase compared to chymotrypsin and cathepsin G (>400-fold). The synthesis and structure-activity relationship of this class are described.

Chymases↗
PubMed2003

Suppression of dextran sodium sulfate-induced colitis in mice by zerumbone, a subtropical ginger sesquiterpene, and nimesulide: separately and in combination.

Ulcerative colitis (UC) and Crohn's disease are inflammatory disorders of unknown cause and difficult to treat, though some synthetic chemicals, including ligands for peroxisome proliferator-activated receptors (PPARs), are anticipated to be useful drugs. In contrast, few food phytochemicals have been reported to suppress colitis in animal models. The present study was undertaken to explore the suppressive efficacy of zerumbone (ZER), a sesquiterpenoid present in the rhizome of Zingiber zerumbet Smith that is used as a condiment in Southeast Asian countries and known to be a potent suppressant of cyclooxygenase (COX)-2 and inducible nitric oxide synthase expression in cell culture systems. Acute colitis was induced by exposing female ICR mice to 5% DSS in drinking water for 1 week. One week prior to DSS administration, the experimental mice were fed ZER alone, nimesulide (NIM, a selective COX-2 inhibitor) alone, or both in combination (1000 ppm each) for a total of 2 weeks. Inflammatory biomarkers, i.e. interleukin (IL)-1alpha and IL-1beta, tumor necrosis factor (TNF)-alpha, and prostaglandin (PG)E(2) and PGF(2alpha) in colonic mucosa were quantified by an enzyme-linked immunosorbent assay in conjunction with histological alterations. Oral feeding of ZER significantly lowered the levels of IL-1beta [inhibitory rate (IR)=34%], TNF-alpha (IR=29%), and PGE(2) (IR=73%) and suppressed DSS-induced colitis, whereas NIM suppressed the histological changes induced by DSS without affecting inflammatory biomarkers. However, their treatment in combination was most effective for suppressing these biomarkers. Our results suggest that ZER is a novel food factor for mitigating experimental UC and that use of a combination of agents, with different modes of actions, may be an effective anti-inflammatory strategy.

Animals↗
PubMed2003

Detection of acceptor sites for antisense oligonucleotides on native folded RNA by fluorescence spectroscopy.

Antisense strategy has high potential for curing diseases and studying gene functions by suppressing the translation step. For the strategy, it is essential to detect acceptor sites of antisense molecules on mRNA under physiological conditions. We propose a new analytical method for the detection of acceptor sites of antisense molecules with high sensitivity. 2'-O-Methyloligoribonucleotide containing 2'-O-(1-pyrenylmethyl)uridine (OMUpy) was chosen as the fluorescence probe. The fluorescence intensity due to the pyrene in single-stranded OMUpy was scarcely observed. When OMUpy was hybridized with the complementary oligoRNA, the fluorescence intensity at 375 nm was remarkably increased. It was found that the increase was derived from the localization of the pyrene by the measurements of time-resolved fluorescence spectroscopy, CD and UV absorption spectra. These results suggest that the change of the fluorescence intensity of OMUpy can be a useful index to monitor hybridization. In this study, we chose Escherichia coli. 16S-rRNA as the model RNA and chose seven regions for probing by OMUpy based on the reported secondary structure of 16S-rRNA. The fluorescence intensity of an equimolar mixture of OMUpy with 16S-rRNA varied depending on the sequence. In particular, the increment in the system of OMUpy-8, which can hybridize with region 887-896 nt of 16S-rRNA, was most significant among the systems. These results indicated that the site targeted by OMUpy-8 was exposed to regulatory molecules, and suggest that the method presented here is useful to design antisense molecules.

Base Sequence↗
PubMed2003

Effects of selected food factors with chemopreventive properties on combined lipopolysaccharide- and interferon-gamma-induced IkappaB degradation in RAW264.7 macrophages.

Degradation of IkappaB (IkappaB) is a key step for nuclear factor-kappaB (NF-kappaB)-induced transcription of certain proinflammatory genes, including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. We selected seven chemopreventive agents and examined their effects on combined lipopolysaccharide- and interferon-gamma-induced IkappaB degradation in RAW264.7 murine macrophages. IkappaB degradation was notably suppressed by 1'-acetoxychavicol acetate (ACA), zerumbone (ZER), and benzylisothiocyanate (BITC), however, not by auraptene (AUR), while the suppressive potencies of nobiletin (NOB), genistein (GEN), and resveratrol (RES) were low, but significant. These results suggest that ACA, ZER, and BITC suppress iNOS/COX-2 gene expression mainly by attenuating IkappaB degradation, while other chemopreventive agents use alternative pathway(s) to suppress the expression of proinflammatory genes.

Animals↗
PubMed2003

A phase II detoxification enzyme inducer from lemongrass: identification of citral and involvement of electrophilic reaction in the enzyme induction.

We have developed a simple system for the sensitive detection and measurement of glutathione S-transferase (GST) activity that detoxifies polycyclic aromatic hydrocarbons using the cultured rat normal liver epithelial cell line, RL34 cells. Citral (3,7-dimethyl-2,6-octadienal) was isolated from the methanol extract of lemongrass (Cymbopogon citratus) and identified as a novel inducer of GST. Citral, a mixture of the two stereoisomers geranial and neral, dose- and time-dependently induced the total and pi-class-specific activities of GST. The structure-activity relationship study revealed that geranial, an E-isomer, was mainly responsible for the inducing activity of citral mixture and the aldehyde group conjugated with a trans-double bond is an essential structural factor. The data were consistent with the in vitro observation that both glutathione (GSH) and protein thiol quickly and specifically reacted with the active isomer geranial, but not neral. Pretreatment of the cells with diethyl maleate significantly enhanced not only the basal activity but also the citral-stimulated activity of GST, while pretreatment with N-acetyl-cysteine inhibited it. Moreover, the treatment of RL 34 cells with geranial for 30 min significantly attenuated the intracellular GSH level, while application for 18 h enhanced it. These results strongly suggested that the electrophilic property characterized by the reactivity with intracellular nucleophiles including protein thiol or glutathione (GSH) plays an important role in the induction of GST. The present study also implied the antioxidant role of GST induction by citral in mouse skin, providing a new insight into skin cancer prevention.

Animals↗
PubMed2003

Identification of a stable chymase inhibitor using a pharmacophore-Based database search.

In general, serine protease chymase inhibitors readily decompose in plasma. We previously found that thiazolidine-2,4-dione and thiadiazole derivatives are also unstable. Using a pharmacophore-based database search, we identified a benzo[b]thiophen-2-sulfonamide derivative as a stable chymase inhibitor. Finding a lead compound with adequate activity and stability by a pharmacophore-based approach is more efficient than modifying an unstable compound to reduce its instability without simultaneously decreasing its inhibitory activity. Our pharmacophore model of chymase inhibitors suggests that the two hydrophobic interactions in the S1 and S1' regions and the two H-bonding interactions between them play important roles in chymase inhibitors.

Animals↗
PubMed2003

Antioxidant activity in vitro of two aromatic compounds from Caesalpinia sappan L.

Two antioxidant compounds were isolated from C. sappan L by multiple steps of column chromatography and thin layer chromatography in succession with superoxide scavenging assay as activity monitor. Structures of the two compounds were determined by spectroscopic methods as 1',4'-dihydro-spiro[benzofuran-3(2H),3'-[3H-2]benzopyran]-1',6',6',7'-tetrol (compound 1) and 3-[[4,5-dihydroxy-2(hydroxymethyl) phenyl]-methyl]-2,3-dihydro-3,6-benzofurandiol (compound 2). Characterization of antioxidant properties of these two compounds was done by determining the inhibitory effect on xanthine oxidase activity as well as scavenging effect on superoxide anion and hydroxyl radicals. Our results indicated that compounds 1 and 2 inhibited xanthine oxidase activity and scavenged superoxide anion and hydroxyl radicals. Compounds 1 and 2 possessed similar radical scavenging activities as ascorbic acid, and they were more effective than other well-known antioxidants such as alpha-tocopherol, beta-carotene, and BHT. As inhibitors of free radical formation, compounds 1 and 2 were more effective than all the other antioxidants tested. In conclusion, compounds 1 and 2 can be regarded as primary antioxidants with radical-scavenging and chain-breaking activities as well as secondary antioxidants with inhibitory effect on radical generation.

Antioxidants↗
PubMed2003

A novel mutation of M1S1 gene found in a Vietnamese patient with gelatinous droplike corneal dystrophy.

To identify the genetic defect in the M1S1 gene responsible for gelatinous droplike corneal dystrophy (GDLD) in a Vietnamese family.Experimental study. Blood samples were collected from a patient and the unaffected members of a GDLD-affected family. Fifty normal unrelated subjects of Vietnamese origin were used as controls. Genomic DNA was extracted from blood leukocytes. DNA analysis of the M1S1 gene was performed using polymerase chain reaction and direct sequencing. Sequencing of the M1S1 gene revealed a deletion of a 12-base-pair (bp) fragment from nucleotide positions 772 to 783 [772 to 783del(ATCTATTACCTG)], resulting in a loss of four amino acids at codons 258 to 261 (L258-liter261del). Yet, an insertion of nucleotide T in place of the missing sequence (772insT) was found. This combined mutation was homozygous in the GDLD-affected patient and heterozygous in his unaffected son and younger sister. Such genetic alteration was excluded in the control population. This is the first report of a mutational analysis performed in a Vietnamese patient with GDLD. In this family, the novel 772 to 783del(ATCTATTACCTG) + 772insT mutation on the M1S1 gene was well cosegregated with the phenotype and thus expected to cause GDLD. Although the M1S1 gene was responsible for GDLD in Vietnamese patients, the mutation found here is completely different from that previously reported in Japanese patients, where GDLD is most frequently seen.

Adult↗
PubMed2003

A case of Kniest dysplasia with retinal detachment and the mutation analysis.

PURPOSE: To report a case of Kniest dysplasia with retinal detachment associated with a novel type II collagen gene (COL2A1) mutation. DESIGN: Interventional case report. METHODS: DNA was isolated from peripheral lymphocytes, and mutational analysis was carried out using polymerase chain reaction and direct sequencing. RESULTS: A 14-year-old Japanese boy was diagnosed with Kniest dysplasia, and ophthalmic examination revealed a retinal detachment in the right eye. He was successfully treated by vitrectomy and silicon oil injection, and his visual acuity improved from 0.01 to 0.22. DNA analysis of COL2A1 revealed a single base-pair substitution at position +5 of intron 20. CONCLUSION: Vitrectomy and silicon oil injection were effective in reattaching the retinal detachment in a Kniest dysplasia patient. The genetic alteration found in this patient suggested that this prevented the normal splicing of COL2A1, resulting in an abnormal type II collagen product.

Adolescent↗
PubMed2003

Mutagenicity of reactive oxygen and nitrogen species as detected by co-culture of activated inflammatory leukocytes and AS52 cells.

Activated inflammatory leukocytes generate a variety of reactive oxygen and nitrogen species (RONS) that may have roles in mutagenesis and carcinogenesis. The purpose of the present study was to explore the relationship between inflammatory leukocyte activation and mutagenesis using co-culture systems. We investigated the mutagenic potentials of 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated differentiated HL-60 (human promyelocytic leukemia cells), and RAW 264.7 cells (murine macrophages) stimulated with lipopolysaccharide (LPS) and interferon (IFN)-gamma by co-culturing each cell line with AS52 cells, a transgenic Chinese hamster ovary cell line. HL-60 cells rapidly generated superoxide (O(2)(-)) 15 min to 1 h (peak at 30 min) following TPA stimulation. RAW 264.7 cells stimulated with LPS and IFN-gamma produced O(2)(-), nitric oxide (NO) and peroxynitrite (ONOO(-)) continuously for 5-25 h. There was a 2.0-fold increase in the mutation frequency of the gpt gene in AS52 cells co-cultured with TPA stimulated HL-60 cells, when compared with non-treated cells. Importantly, this increase in mutation frequency was significantly suppressed by antioxidants, such as superoxide dismutase (SOD) and diphenylene iodonium (DPI), an NADPH oxidase inhibitor (inhibition rates: IRs = 18.2 and 35.1%, respectively). Similarly, co-culture of AS52 cells with LPS/IFN-gamma-stimulated RAW 264.7 cells also increased the mutation frequency of the gpt gene by 2.6-fold, and this increase in mutation frequency was suppressed by SOD, DPI and N(5)-(1-iminoethyl)-L-ornithine dihydrochloride (L-NIO), an specific iNOS inhibitor (IRs = 58.3, 70.8 and 70.8%, respectively). In co-culture experiments, activated HL-60 and RAW 264.7 cells increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in AS52 cells when compared with non-treated controls (1.7- and 1.6-fold, respectively). Treatment of AS52 cells with hydrogen peroxide (H(2)O(2), 100 micro M), ONOO(-) (100 micro M) and SIN-1 (100 micro M), a ONOO(-) generator, also increased the mutation frequency of the gpt gene (4.6-, 5.4- and 2.8-fold, respectively). Taken together, these results support the hypothesis that RONS, derived from activated inflammatory leukocytes, are mutagenic in the biological systems, and that RONS generation inhibitors are potentially anti-mutagenic, and thus may be useful in cancer preventive strategies.

Animals↗
PubMed2003

Synthesis of antisense oligonucleotides containing photocleavable protecting groups on the thymine bases and their photoinduced duplex formation.

Oligonucleotides containing photocleavable protecting groups at thymine bases were synthesized to induce the duplex formation by photo-irradiation. 6-Nitroveratryloxycarbonyl (NVOC) group was used for the photocleavable protecting group at N3 position of thymidine. An oligonucleotide containing NVOC groups (NVOC-ODN2:5'-dATG CAC CAT(NVOC) TCT(NVOC)GTC TGT-3') was synthesized by phosphoramidite method. The NVOC groups were found to be removable by UV irradiation at wavelength of 365 nm for 5 h. UV-melting temperature (Tm value) analysis indicated that the duplex of NVOC-ODN2 with the complementary RNA was significantly unstable compared with the unmodified DNA/RNA duplex (delta Tm=-13 degrees C). After UV irradiation at 365 nm, the Tm value of the mixture increased to the almost same as that of the unmodified duplex. These results suggest that the RNA binding ability of the NVOC-ODN2 can be induced by photocleavage of the NVOC groups.

Base Sequence↗
PubMed2003

Detection of acceptor sites for antisense oligonucleotides on native folded RNA by fluorescence-labeled oligonucleotide.

Pyrene-labeled 2'-O-methyloligoribonucleotide (OMUpy) and 5'-Ru(II) complex labeled oligodeoxyribonucleotie (Ru-probe) were prepared as the fluorescence probes to detect acceptor sites of antisense molecules on native folded RNA under the physiological condition. OMUpy showed the remarkable increase of the fluorescence intensity (334-fold at 375 nm) only when hybridized with complementary oligoRNA. When OMUpy was applied to E. coli 16S-rRNA, the fluorescence intensities were increased in a sequence specific manner. The rotational correlation time of Ru-probe complementary to 16S-rRNA were largely dependent on the sequence of Ru-probe. These results suggest that the accessibility of the antisense molecules for RNA can be evaluated by those fluorescent probes.

Fluorescent Dyes↗
PubMed2003

Photodynamic antisense therapy: regulation of cervical carcinoma cells by psoralen-conjugated oligonucleotides.

To reinforce antisense effects, we focused on the photo-cross-linking ability of psoralen derivatives and examined the applicability of the photodynamic antisense therapy to cancer cells using psoralen-conjugated oligo(nucleosides phosphorothioate)s (Ps-S-Oligo). The regulatory effects of Ps-S-Oligos on the proliferation of cervical carcinoma were evaluated. The inhibitory effects were found to be significant (IC50=16 nM) without any drug delivery systems, and it was also found that the mechanism was associated with the p53 induced apoptosis. This result suggests that the photodynamic antisense therapy will be a promising concept for the cancer therapy.

Apoptosis↗