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Biomedical subjects

M Hattori

Publications and source records attributed to M Hattori.

At least 55 records · Page 3Linked to original sources
PubMed2001

A novel sample decomposition technique at atmospheric pressure for the determination of Os abundances in iron meteorites using isotope dilution inductively coupled plasma-mass spectrometry.

A safe and reliable analytical technique for the determination of Os abundances in ten iron meteorites of various chemical groups was developed using isotope dilution inductively coupled plasma-mass spectrometry coupled with a sample decomposition technique. A major advantage of the sample decomposition technique developed here is that the pressure inside the reaction flask is not increased through the decomposition reaction because the flask is a fully opened system, obviating the risk of explosion of the glass apparatus. Another advantage is that there is no restriction in the sample size being decomposed. In this study, about 2 g of metallic sample were decomposed safely, and this sample size, > 10 times larger than that typically used for the Carius tube technique, allows one to obtain more reliable Os data for heterogeneous samples. The metallic samples were decomposed in a glass flask purged with Ar. Since the O2 was purged from the reaction flask, Os was not oxidised to volatile OsO4, thereby preventing significant evaporation loss of Os. The typical recovery of Os throughout the sample decomposition and separation processes was > 80%, and the total Os blank through the decomposition of a 1 g amount of sample was less than 20 pg. Os abundances were determined by means of stable isotope dilution mass spectrometry using a 190Os-enriched isotopic tracer. Except for Sikhote-Alin, the measured Os abundances in almost all the iron meteorites exhibited a good agreement with the previously published Os abundance data, within the analytical uncertainty achieved in this study (2-5%). For the Sikhote-Alin meteorite, on the basis of a better correlation between Os and Ir abundances, we believe that our Os abundance data should be more reliable. The Os abundance data obtained in this work clearly demonstrated the suitability of the newly developed sample decomposition procedure for low level Os determinations.

Journal Article↗
PubMed2001

Cytotoxic mono-tetrahydrofuran ring acetogenins from leaves of Annona montana.

Further studies on leaves of Annona montana led to isolation of one iso-acetogenin, montanacin G, three pairs of acetogenins, montanacin H-J and 34-epi-montanacin H-J, together with four known acetogenins, gigantetrocins A and B, annonacin and cis-annonacin. Montanacin G belongs to the iso-acetogenin group with a terminal 2,4-trans-ketolactone unit. Montanacin H-J and 34-epi-montanacin H-J contain the rare gamma-hydroxy-gamma-methyl-gamma-lactone moiety. The cytotoxic activities of these compounds, together with previously reported acetogenins, montanacins B and C, were examined against Meth-A and LLC tumor cell lines in vitro.

4-Butyrolactone↗
PubMed2001

Anticomplement activity of terpenoids from the spores of Ganoderma lucidum.

A new lanostane-type terpenoid, lucidenic acid SP1 (1), was isolated from a CHCl(3)-soluble fraction of Ganoderma lucidum spores together with four other known compounds (2 - 5). The structure of lucidenic acid SP1 was determined to be 3 beta,7 beta-dihydroxy-4,4,14 alpha-trimethyl-11,15-dioxo-5 alpha-chol-8-en-24-oic acid by spectroscopic means including 2D-NMR. Twelve triterpenes (1-12) isolated from G. lucidum spores were investigated in vitro for their anticomplementary activity. Compounds 1 - 5 were inactive, whereas ganoderiol F (8), ganodermanondiol (9) and ganodermanontriol (10) showed a strong anticomplement activity against the classical pathway (CP) of the complement system with IC(50) values of 4.8, 41.7, and 17.2 microM, respectively. The potency of these triterpene alcohols (8-10) in inhibiting CP activity was improved when the number of hydroxymethyl groups on the side chain moiety is increased. On the other hand, the ganoderic acids 1-7, which contain a carboxyl group in the side chain, and lucidumols A and B (11, 12) had little activity on this system.

Complement Activation↗
PubMed2001

Cytotoxic alkaloids and a flavan from the bulbs of Crinum asiaticum var. japonicum.

A new pyrrolophenanthridone alkaloid, criasiaticidine A (1), was isolated from the bulbs of Crinum asiaticum var. japonicum, together with pratorimine (2), lycorine (3) and 4'-hydroxy-7-methoxyflavan (4). The structure of the new alkaloid was determined to be 4,5-etheno-9,10-dihydroxy-6-phenanthridone by spectroscopic means. The cytotoxicity of the isolated compounds 1-4 was evaluated in vitro against Meth-A (mouse sarcoma) and Lewis lung carcinoma (mouse lung carcinoma) tumor cell lines. Furthermore, 3 was examined for in vivo antitumor activity with LLC tumor cells.

Alkaloids↗
PubMed2001

The heterocyclic ring fission and dehydroxylation of catechins and related compounds by Eubacterium sp. strain SDG-2, a human intestinal bacterium.

A human intestinal bacterium, Eubacterium (E.) sp. strain SDG-2, was tested for its ability to metabolize various (3R)- and (3S)-flavan-3-ols and their 3-O-gallates. This bacterium cleaved the C-ring of (3R)- and (3S)-flavan-3-ols to give 1,3-diphenylpropan-2-ol derivatives, but not their 3-O-gallates. Furthermore, E. sp. strain SDG-2 had the ability of p-dehydroxylation in the B-ring of (3R)-flavan-3-ols, such as (-)-catechin, (-)-epicatechin, (-)-gallocatechin and (-)-epigallocatechin, but not of (3S)-flavan-3-ols, such as (+)-catechin and (+)-epicatechin.

Biotransformation↗
PubMed2001

Triterpenes and lignans from Artemisia caruifolia and their cytotoxic effects on meth-A and LLC tumor cell lines.

One new triterpene, 3beta-hydroxy-29-norcycloart-24-one (1), and four new lignans, caruilignans (2-5), together with six known compounds were isolated from the aerial part of Artemisia caruifolia BUCH.-HAM. ex TOXB. Their structures were determined by various spectroscopic means. Most of the isolated lignans were moderately cytotoxic to Meth-A cells with ED50 values of 5-10 microg/ml, but not to Lowis lung carcinoma (LLC) cells. An oxime derivative of 1 showed more potent cytotoxic activity against Meth-A and LLC cells than the original triterpene 1.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Kaempferol acetylrhamnosides from the rhizome of Dryopteris crassirhizoma and their inhibitory effects on three different activities of human immunodeficiency virus-1 reverse transcriptase.

Three new kaempferol glycosides, called crassirhizomosides A (1), B (2) and C (3), were isolated from the rhizome of Dryopteris crassirhizoma (Aspidiaceae), together with the known kaempferol glycoside, sutchuenoside A (4). The structures of 1-3 were determined as kaempferol 3-alpha-L-(2,4-di-O-acetyl)rhamnopyranoside-7-alpha-L-rhamnopyranoside, kaempferol 3-alpha-L-(3,4-di-O-acetyl)rhamnopyranoside, and kaempferol 3-alpha-L-(2,3-di-O-acetyl)rhamnopyranosside-7-alpha-L-rhamnopyranoside, respectively, by chemical and spectroscopic means. Inhibitory effects of 1-4 and kaempferol on human immunodeficiency virus reverse transcriptase-associated DNA polymerase (RNA-dependent DNA polymerase and DNA-dependent DNA polymerase) and RNase H activities were investigated.

Carbohydrates↗
PubMed2001

Three new triterpene saponins from the seeds of Aesculus chinensis.

Three new triterpenoid saponins were isolated from the seeds of Aesculus chinensis, and characterized as 22-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVg, 1), 22-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVh, 2) and 16-angeloyl-21-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin VIb, 3), together with two known compounds, escin IIIa (4) and desacylescin 1 (5). Their structures were established on the basis of spectroscopic and chemical evidence.

Carbohydrate Sequence↗
PubMed2001

Medicinal foodstuffs. XXIV. Chemical constituents of the processed leaves of Apocynum venetum L.: absolute stereostructures of apocynosides I and II.

Two new ionone glucosides, named apocynosides I and II, were isolated from the roasted leaves of Apocynum venetum L. together with nine known compounds. The absolute stereostructures of apocynosides I and II were determined by chemical and physicochemical evidence, which included the application of a modified Mosher's method and the circular dichroism helicity rule.

Apocynaceae↗
PubMed2001

Inhibitory effects on HIV-1 protease of tri-p-coumaroylspermidine from Artemisia caruifolia and related amides.

From a methanol extract of Artemisia caruifolia, which showed a moderate inhibitory activity on HIV-1 protease in a preliminary screening, N1,N5,N10-tri-p-coumaroylspermidine and three dicaffeoylquinic acids were isolated. The former compound was found to appreciably inhibit HIV-1 protease. Of related amides which were chemically synthesized, N1,N5,N10,N14-tetra-p-coumaroylspermine and N1,N4,N7,N10,N13-penta-p-coumaroylte-traethylenepentamine inhibited HIV-1 protease more potently than N1,N5,N10-tri-p-coumaroylspermidine.

Amides↗
PubMed2001

New paeonilactone-A adducts formed by anaerobic incubation of paeoniflorin with Lactobacillus brevis in the presence of arylthiols.

During the course of preparing anticonvulsant paeonimetabolin-I adducts, new paeonilactone-A adducts: 9-phenylthiopaeonilactone-A, 9-(o-tolylthio)paeonilactone-A, 9-(m-tolylthio)paeonilactone-A, 9-(p-tolylthio)-paeonilactone-A and 9-(2-naphthylthio)paeonilactone-A, were obtained along with expected paeonimetabolin-I adducts by anaerobic incubation of paeoniflorin from peony roots with Lactobacillus brevis in the presence of the aromatic thiols, phenylthiol, o-tolylthiol, m-tolylthiol, p-tolylthiol and 2-naphthylthiol. The structures of these compounds were determined by spectroscopic methods including two dimensional (2D) NMR.

Anaerobiosis↗
PubMed2001

Protective effect of Salvia miltiorrhiza on angiotensin II-induced hypertrophic responses in neonatal rat cardiac cells.

The effect of the root of Salvia miltiorrhiza (SM) on angiotensin II (Ang II)-induced hypertrophic responses was examined in cultured neonatal rat cardiac cells (cardiomyocytes and non-cardiomyocytes). The methanol eluate fraction (SM2) of the water extract and the ethyl acetate-insoluble fraction (SM3) and its soluble fraction (SM4) partitioned from the methanol extract were prepared. Treatment with SM4 (5-80 microg/ml), not SM2 and SM3, for 24 h produced dose-dependent cytotoxicity against cardiac cells relative to the reduction in viability and the morphological injury of cardiomyocytes. SM2 or SM3 in the absence of Ang II affected neither hyperplastic nor hypertrophic growth of both cell types. However, SM3 (40 microg/ml) attenuated the positive chronotropic responsiveness of cardiomyocytes to Ang II (1 nM) stimulation, whereas Ang II-induced increase in non-cardiomyocyte number was decreased only by SM2 (40 microg/ml) treatment. Furthermore, SM3 suppressed Ang II-induced enlargement of cell size by preceding Ang II-induced induction of immediate early response gene (c-jun) expression in cardiomyocytes, while SM2 decreased Ang II-induced DNA synthesis in non-cardiomyocytes. Moreover, three phenolic compounds and tanshinone IIA that differed quantitatively among three SM fractions were identified by reverse-phase high performance liquid chromatography. Thus, the present findings indicate that the root of SM is an effective inhibitor of Ang II action and has a plural effective constituent, which possess different pharmacological activities on Ang II-induced hypertrophy and hyperplasia in cultured neonatal rat cardiac cells.

Angiotensin II↗
PubMed2001

dlk inhibits stem cell factor-induced colony formation of murine hematopoietic progenitors: Hes-1-independent effect.

Delta-like (dlk) is a family of transmembrane proteins containing epidermal growth factor-like repeat motifs homologous to the notch/delta/serrate family. Recent studies suggest that dlk is a negative regulator of adipocyte differentiation, a promoting factor of cobblestone area colony formation, and a molecule which influences stromal cell-pre-B cell interactions and augments cellularity of developing thymocytes. However, the role of dlk in regulating the growth and differentiation of hematopoietic progenitors remains unclear. In the present study, we examined the effect of dlk on the proliferation of murine hematopoietic progenitors by hematopoietic growth factors. Soluble dlk-IgG Fc chimeric protein completely inhibited the colony formation of lineage-marker negative (Lin-) bone marrow cells by GM-CSF, G-CSF, or macrophage-CSF (M-CSF) in the presence of stem cell factor (SCF). However, dlk failed to inhibit the colony formation of Lin- bone marrow cells by CSF, as described above, or M-CSF plus interleukin 3. Furthermore, dlk failed to inhibit the colony formation of Hes-1-null fetal liver cells by M-CSF in the presence of SCF. These findings suggest that dlk is an important regulator of hematopoietic progenitor proliferation. Depending on the presence of SCF, dlk may act as a growth inhibitor, although dlk signaling does not mediate Hes-1 transcription factor.

Animals↗
PubMed2001

A patient with chronic hepatitis C who obtained sustained response by retreatment of interferon after decrease of viral load and mutation in interferon sensitivity determining region.

A 44-year-old man with chronic hepatitis C received three courses of interferon (IFN) therapy. HCV genotype was 1b, viral load was 1,200 kcopies/ml and interferon sensitivity determining region (ISDR) was the intermediate type before the 1st IFN therapy. The 1st and 2nd IFN therapies resulted in failure to yield a sustained response. Seven years after from the 1st therapy, viral load had decreased to 15 kcopies/ml and ISDR had changed to mutant type. The 3rd IFN therapy yielded sustained response. Thus, we should consider retreatment with IFN when a decrease of the viral load and change of ISDR to mutant type are observed.

Adult↗
PubMed2001

Casting accuracy of experimental Ti-Cu alloys.

The purpose of the present study was to investigate the casting accuracy and the dimensional change of experimental titanium-copper alloys (3.0 and 5.0 mass% Cu; hereafter, only "%" will be used) and to compare the findings with those of pure titanium. Castings were made using an argon-arc melting/pressure difference-casting unit. The fit of the metals cast in both full crown and MOD inlay dies was evaluated by measuring the distance between the shoulder margin and the cervical shoulder of the die. The changes in the inner diameter of castings were determined. In addition, surface roughness measurements inside the castings were carried out using a conventional profilometer, and thermal expansion measurements were made on cast cylindrical specimens using a differential dilatometer. There were no significant differences in dimensional change between pure titanium and the titanium-copper alloys. The fit of the titanium-copper alloys was inferior to pure titanium. The results of surface roughness measurements showed significance differences between the roughness of the pure titanium and titanium-copper alloys.

Analysis of Variance↗