Biomedical subjects

T Murakami

Publications and source records attributed to T Murakami.

At least 163 records · Page 9Linked to original sources

PubMed2001

Epidermal growth factor receptor overexpression and genetic aberrations in metastatic squamous-cell carcinoma of the skin.

BACKGROUND: Cutaneous squamous-cell carcinoma (SCC) sometimes causes lymph node metastasis and results in poor prognosis. However, little is known about cytogenetic alterations underlying tumor progression or metastasis. The aim of the present study was to investigate the genetic aberrations and expression of epidermal growth factor receptor (EGFR) in metastatic SCC of the skin. METHODS: We undertook comparative genomic hybridization (CGH) analysis of 4 specimens which were obtained from a case of cutaneous SCC, including the primary lesion and 3 lymph nodes of the metastatic lesion. RESULTS: Only one amplified locus (7p12-13) was detected in any metastatic lymph node, in which the EGFR gene is located. Therefore, we applied immunohistochemistry for EGFR to 5 cases of metastatic SCC including the case analyzed using CGH and 4 other cases (5 primary and 5 metastatic lesions). EGFR was expressed in 4 of 5 cases (both primary and metastatic lesions, including the case analyzed using CGH), and the staining patterns of primary and metastatic lesions were different. The primary tumors were focally weakly positive for immunostaining (+), whereas the 4 metastases were diffusely and strongly positive (+++). CONCLUSIONS: Our findings suggest that the clone with EGFR expression might selectively metastasize in some cutaneous SCCs. The existence of an EGFR-negative case reveals that EGFR expression is not always required for skin carcinogenesis, but expression of EGFR might confer metastatic potential of cutaneous SCCs.

Carcinoma, Squamous Cell↗

PubMed2001

Quantitative comparison of anti-fading mounting media for confocal laser scanning microscopy.

Fading is one of the major obstacles to reliable observation in fluorescence microscopy. Using a confocal laser scanning microscope (CLSM) coupled to a computer, we quantitatively measured fading of fluorescence to formulate an equation, evaluated the anti-fading ability of several anti-fading media, and restored the faded images to the original level according to this equation. NIH 3T3 cells were stained with fluorescein isothiocyanate (FITC)-phalloidin, mounted with several commercial and homemade anti-fade media, and observed with CLSM under repeated illumination. With any mounting medium, attenuation of fluorescence intensity at a certain pixel occurred stepwise and the decrease was proportional to the intensity of the previous scan. From these results, we formulated an equation that has three coefficients: anti-fading factor (A), indicating the ability to retard fading; fluorescent intensity at the first scan (EM(1)); and background fluorescence (B). The fluorescent intensity at a certain point following nth scan is given as EM(n) = EM(1) * A ((n-1)). This equation was available for restoring faded images to their original states, even after the image had faded to only 60% of its original intensity.

3T3 Cells↗

PubMed2001

Calcitonin induces IL-6 production via both PKA and PKC pathways in the pituitary folliculo-stellate cell line.

It has been demonstrated that calcitonin-binding sites are present in a variety of tissue types, including in the pituitary gland. Interleukin-6 (IL-6) is also produced in the pituitary and it regulates the secretion of various hormones. In this study, we examined the expression of the calcitonin receptor and the mechanism of IL-6 production induced by calcitonin in the pituitary folliculo-stellate cell line (TtT/GF). The mRNA of calcitonin receptor subtype C1a, but not that of C1b, was detected by RT-PCR in TtT/GF cells and in the normal mouse pituitary. Calcitonin increased cAMP accumulation and IL-6 production in a concentration-dependent manner in TtT/GF cells. As calcitonin activates the PKA and PKC pathways, we investigated the contributions of PKA and PKC to IL-6 production. IL-6 production was only slightly increased by either 8-bromo-cAMP (1 mM) or phorbol 12-myristate 13-acetate (100 nM) alone. However, IL-6 was synergistically induced in the presence of both 8-bromo-cAMP (1 mM) and phorbol 12myristate 13-acetate (100 nM). Furthermore, calcitonin-induced IL-6 production was completely suppressed by H-89 (PKA inhibitor) or GF109203X (PKC inhibitor), indicating that the activation of both PKA and PKC is necessary for calcitonin-induced IL-6 production. On the other hand, pertussis toxin (G(i)/G(o) signaling inhibitor) treatment achieved an approximately 9-fold increase in calcitonin-induced IL-6 production. These results show that calcitonin-stimulated IL-6 production is mediated via both PKA- and PKC-signaling pathways, whereas calcitonin also suppresses IL-6 production by activating G(i)/G(o) proteins in folliculo-stellate cells.

Animals↗

PubMed2001

Expression and function of P-glycoprotein in rats with carbon tetrachloride-induced acute hepatic failure.

Acute hepatic failure was induced experimentally in rats by intraperitoneal injection of 2.5 mL kg(-1) carbon tetrachloride (CCl4), and the effects on the expression and function of P-glycoprotein in the liver, kidney and brain were evaluated. The CCl4 injection significantly increased the indicators of hepatic function (glutamate oxaloacetate transaminase, glutamate pyruvate transaminase), but not of renal function (blood urea nitrogen, glomerular filtration rate). In rats with acute hepatic failure, the hepatic P-glycoprotein concentration increased 1.5-fold and the ATP concentration decreased to approximately 40% that in control rats. In contrast, P-glycoprotein concentrations in the kidney and brain and ATP concentrations in the kidney remained unchanged. The in-vivo P-glycoprotein function in these tissues was suppressed as evaluated by biliary and renal secretory clearances and brain distribution of rhodamine 123, a P-glycoprotein substrate. These findings suggest that factors other than P-glycoprotein concentration are involved in the systemic suppression of P-glycoprotein function in diseased rats. In Caco-2 cells, plasma collected from CCl4-treated rats exhibited a greater inhibitory effect on P-glycoprotein-mediated transport of rhodamine 123 than that from control rats, suggesting the accumulation of an endogenous P-glycoprotein substrate/inhibitor in the plasma of diseased rats. In fact, the plasma concentration of corticosterone, an endogenous P-glycoprotein substrate, increased 2-fold in CCl4-treated rats compared with control rats. It was demonstrated that P-glycoprotein function is systemically suppressed in rats with CCl4-induced acute hepatic failure, not only in the target organ (liver), but also in other organs (kidney and brain), although the P-glycoprotein concentration remained unchanged in the kidney and brain, and increased in the liver. In the systemic suppression of the P-glycoprotein function in the diseased state, the alteration of plasma concentrations or components of endogenous P-glycoprotein-related compounds, such as corticosterone, would likely be involved.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Localization of plectin and other related proteins along the sarcolemma in smooth muscle cells of rat colon.

Plectin is a versatile linker protein which is associated with various types of cytoskeletal components and/or filaments including intermediate filaments. To better understand the functional roles of plectin in smooth muscle cells, we examined the distribution of plectin and other related proteins in rat colon smooth muscles by confocal laser and electron microscopy. The sarcolemma of smooth muscle cells exhibits two ultrastructurally distinct domains, domains associated with dense plaques and caveola-rich domains. Staining with anti-plectin and anti-desmin antibodies showed that plectin was localized along the sarcolemma in an intermittent manner and desmin was distributed in the sarcoplasm and intermittently at the cell periphery where it was codistributed with desmin. Plectin exhibited complementary and non-overlapping distribution to caveolin-1 and dystrophin, components of caveola domains, whereas plectin was codistributed with vinculin, talin and integrin beta1, components of dense plaques. Plectin was also codistributed with beta2-chain laminin but not with beta1-chain laminin. Electron microscopic observations on the sarcolemma revealed close association of intermediate filaments with dense plaques. Correlated confocal and electron microscopy clearly demonstrated that anti-plectin fluorescence corresponded to dense plaques but not to caveola domains in electron microscopic images. These findings indicate that plectin is confined to dense plaques to which desmin intermediate filaments may be anchored in rat colon smooth muscle cells.

Animals↗

PubMed2001

Medicinal foodstuffs. XXV. Hepatoprotective principle and structures of ionone glucoside, phenethyl glycoside, and flavonol oligoglycosides from young seedpods of garden peas, Pisum sativum L.

A new ionone glucoside, pisumionoside, a phenethyl glycoside, sayaendoside, and two acylated flavonol oligoglycosides, pisumflavonosides I and II, were isolated from the young seedpods of garden peas, Pisum sativum L., together with quercetin and kaempferol 3-O-(6-O-trans-p-coumaroyl)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosyl (1-->2)-beta-D-glucopyranosides and quercetin and kaempferol 3-sophorotriosides. The structures of pisumionoside, sayaendoside, and pisumflavonosides I and II were determined on the basis of chemical and physicochemical evidence, respectively. Quercetin 3-sophorotrioside, a principle component, was found to show protective effects on liver injury induced by D-galactosamine and lipopolysaccharide and by carbon tetrachloride in mice.

Animals↗

PubMed2001

Bioactive saponins and glycosides. XIX. Notoginseng (3): immunological adjuvant activity of notoginsenosides and related saponins: structures of notoginsenosides-L, -M, and -N from the roots of Panax notoginseng (Burk.) F. H. Chen.

New dammarane-type triterpene saponins, notoginsenosides-L, -M, and -N, were isolated from the glycosidic fraction of the dried roots of Panax notoginseng (Burk.) F. H. Chen. Their structures were elucidated on the basis of chemical and physicochemical evidence. Immunological adjuvant activities of the principal notoginsenosides and related dammarane-type triterpene saponins were examined and notoginsenosides-D, -G, -H, and -K were found to increase the serum IgG level in mice sensitized with ovalbumin.

Adjuvants, Immunologic↗

PubMed2001

Medicinal foodstuffs. XXI. Structures of new cucurbitane-type triterpene glycosides, goyaglycosides-a, -b, -c, -d, -e, -f, -g, and -h, and new oleanane-type triterpene saponins, goyasaponins I, II, and III, from the fresh fruit of Japanese Momordica charantia L.

Eight cucurbitane-type triterpene glycosides called goyaglycosides-a, -b, -c, -d, -e, -f, -g, and -h and three oleanane-type triterpene saponins termed goyasaponins I, II, and III were isolated from the fresh fruit of Japanese Momordica charantia L. (Cucurbitaceae) together with five known cucurbitane-type triterpene glycosides momordicosides A, C, F1, I, and K. The structures of goyaglycosides and goyasaponins were elucidated on the basis of chemical and physicochemical evidence.

Glycosides↗

PubMed2001

Medicinal foodstuffs. XXII. Structures of oleanane-type triterpene oligoglycosides, pisumsaponins I and II, and kaurane-type diterpene oligoglycosides, pisumosides A and B, from green peas, the immature seeds of Pisum sativum L.

Two new oleanane-type triterpene oligoglycosides, pisumsaponins I and II, and two new kaurane-type diterpene oligoglycosides, pisumosides A and B, were isolated from the immature seeds (green peas) of Pisum sativum L. together with soyasaponin I, bersimoside I, dehydrosoyasaponin I, and their 6'-methyl esters. The structures of pisumsaponins and pisumosides were determined on the basis of chemical and physicochemical evidence as 22-O-malonylsoyasapogenol B 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucopyranosiduronic acid (22-O-malonylsoyasaponin I), sandosapogenol 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-galactopyranosyl(1-->2)-beta-D-glucopyranosiduronic acid, 17-O-beta-D-glucopyranosyl-6beta,7beta,13gamma,17-tetrahydroxy-19-kauranoic acid 19-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside, and 6beta,7beta,13beta,17-tetrahydroxy-19-kauranoic acid 19-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranoside, respectively.

Carbohydrate Conformation↗

PubMed2001

Bioactive saponins and glycosides. XVIII. Nortriterpene and triterpene oligoglycosides from the fresh leaves of Euptelea polyandra Sieb. et Zucc. (2): Structures of eupteleasaponins VI, VI acetate, VII, VIII, IX, X, XI, and XII.

Following the elucidation of eupteleasaponins I, II, III, IV, V, and V acetate, eupteleasaponins VI, VI acetate, VII, VIII, IX, X, XI, and XII were isolated from the fresh leaves of Euptelea polyandra Sieb. et Zucc. The structures of eupteleasaponins VI-XII were determined on the basis of chemical and physicochemical evidence.

Carbohydrate Conformation↗

PubMed2001

Medicinal foodstuffs. XXIII. Structures of new oleanane-type triterpene oligoglycosides, basellasaponins A, B, C, and D, from the fresh aerial parts of Basella rubra L.

Basellasaponins A, B, C, and D, oleanane-type triterpene oligoglycosides having the dioxolane-type substituent, were isolated from the fresh aerial parts of Basella rubra L. together with betavulgaroside I, spinacoside C, and momordins IIb and IIc. The chemical structures of basellasaponins A, B, C, and D were determined from chemical and physicochemical evidence.

Carbohydrate Conformation↗

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

Medicinal flowers. III. Marigold. (1): hypoglycemic, gastric emptying inhibitory, and gastroprotective principles and new oleanane-type triterpene oligoglycosides, calendasaponins A, B, C, and D, from Egyptian Calendula officinalis.

The methanolic extract and its 1-butanol-soluble fraction from the flowers of Calendula officinalis were found to show a hypoglycemic effect, inhibitory activity of gastric emptying, and gastroprotective effect. From the 1-butanol-soluble fraction, four new triterpene oligoglycosides, calendasaponins A, B, C, and D, were isolated, together with eight known saponins, seven known flavonol glycosides, and a known sesquiterpene glucoside. Their structures were elucidated on the basis of chemical and physicochemical evidence. The principal saponin constituents, glycosides A, B, C, D, and F, exhibited potent inhibitory effects on an increase in serum glucose levels in glucose-loaded rats, gastric emptying in mice, and ethanol- and indomethacin-induced gastric lesions in rats. Some structure-activity relationships are discussed.

Animals↗

PubMed2001

Relation of QT-interval variability to ventricular arrhythmias during percutaneous transluminal coronary angioplasty.

The present study investigated the role of the dispersion of QT interval in percutaneous transluminal coronary angioplasty (PTCA)-induced ventricular tachyarrhythmias. Patients with effort angina without a previous myocardial infarction (n = 22), who had single-vessel disease of the anterior descending coronary artery (LAD), underwent PTCA if the coronary lesion was 75% or more stenosed in segment 6 or 7 of the LAD. The standard 12-lead ECG was continuously recorded during the procedure. Averaged QTc and QTac intervals, where QTac was the interval from the beginning of QRS complex to the nadir of T wave corrected by Bazett's formula, did not change significantly during PTCA. Of the 22 patients, 7 showed ventricular arrhythmias during PTCA. The maximum difference (deltaQTc) and the standard deviation (QTcSD) of the corrected QT interval in the standard 12-lead ECG increased significantly during PTCA in the 7 patients with ventricular arrhythmias, whereas they decrreased in the 15 patients without ventricular arrhythmias. deltaQTac and QTacSD were not affected by PTCA regardless of ventricular arrhythmias, which shows that the increases in the variation of the ventricular repolarization process play a role in PTCA-induced ventricular arrhythmias.

Aged↗

PubMed2001

1-Aminocyclopropane-1-carboxylate synthase of Penicillium citrinum: primary structure and expression in Escherichia coli and Saccharomyces cerevisiae.

A plant hormone, ethylene, is formed through 1-aminocyclopropane-1-carboxylic acid (ACC). A fungus, Penicillium citrinum, was found to synthesize ACC and to degrade ACC into 2-oxobutyrate and ammonia. ACC synthase, responsible for ACC synthesis in P. citrinum, was characterized on the molecular level by sequencing of N terminal and proteolytic peptides of the enzyme, and cloning and sequencing of its cDNA. The ACC synthase from P. citrinum had 430 amino acid residues and a shorter C terminal than the plant enzyme. The enzyme purified from Escherichia coli transformed with ACC-synthase-encoding DNA showed similar properties to those of the purified enzyme from P. citrinum. Saccharomyces cerevisiae with ACC synthase accumulated ACC in the medium with increasing time of incubation. The sequence of ACC synthase from P. citrinum was compared with that of the plant enzyme with discussion about important residues for catalysis.

Amino Acid Sequence↗

PubMed2001

Inhibitory effects of capsaicinoids on fatty acid desaturation in a rat liver cell line.

The inhibitory effects of such vanillylamides as capsaicin and nine capsaicinoids on fatty acid desaturation in liver cells were investigated by using the cultured rat liver cell line, BRL-3A. When capsaicin was added to the medium, it had a relatively strong inhibitory effect on delta6 desaturation and clear inhibitory effects on delta5 and C24delta16 desaturation (delta16 desaturation of C24-polyunsaturated fatty acids). Capsaicinoids with side carbon chain lengths of C10:0 and C12:0 expressed the maximum inhibitory effects of the nine capsaicinoids on fatty acid desaturation in the BRL-3A cells. The inhibitory effects of the capsaicinoids were not correlated with their pungency.

Animals↗

PubMed2001

Mechanical strain effect on bone-resorbing activity and messenger RNA expressions of marker enzymes in isolated osteoclast culture.

Adaptive modeling and remodeling are controlled by the activities of osteoblasts and osteoclasts, which are capable of sensing their mechanical environments and regulating deposition or resorption of bone matrix. The effects of mechanical stimuli on isolated osteoclasts have been scarcely examined because it has proven to be difficult to prepare a number of pure osteoclasts and to cultivate them on mineralized substratum during mechanical stimulation. Recently, we developed an apparatus for applying mechanical stretching to the ivory slice/plastic plate component on which cells could be cultured. The loading frequency, strain rate, and generated strain over an ivory surface could be controlled by a personal computer. Using this apparatus, we examined the role of mechanical stretching on the bone-resorbing activity of the osteoclasts. Mature and highly enriched osteoclasts were cultured for 2, 12, and 24 h on the ivory/plate component while being subjected to intermittent tensile strain. The stretched osteoclasts showed enhanced messenger RNA (mRNA) expression levels of osteoclast marker enzymes, tartrate-resistant acid phosphatase (TRAP), and cathepsin K and increases of resorbed-pit formation, suggesting that the mechanical stretching up-regulated the bone-resorbing activity of the osteoclasts. A stretch-activated cation (SA-cat) channel blocker significantly inhibited the increases of the mRNA level and pit formation after 24 h of stretching. This study suggested the possibility that the mature osteoclasts responded to mechanical stretching through a mechanism involving a SA-cat channel in the absence of mesenchymal cells and, as a result, up-regulated their bone-resorbing activity.

Acid Phosphatase↗

PubMed2001

High prevalence of vitamin D deficiency in Japanese female patients with Graves' disease.

We reported previously that vitamin D deficiency is a causal mechanism of postoperative tetany in patients with Graves' disease. The aim of the present study was to determine the prevalence of vitamin D deficiency by reviewing serum 25(OH)D levels in 208 patients with Graves' disease (146 women, 62 men) during a 1 year period. Serum 25(OH)D levels were significantly lower (p < 0.001) in female Graves' patients (31.8 +/- 13.3 nmol/l) than in male patients (41.3 +/- 15.0 nmol/l). Vitamin D deficiency (defined as a serum 25(OH)D value below 25 nmol/l) was found in 40% of female patients and in 18% of male patients (p < 0.005). There was a significant seasonal variation in the 25(OH)D concentrations in female patients [amplitude 6.38 (95% CI, 5.42-7.56)], with values below 25 nmol/l found in 58% of female patients during the winter months. There were significant (p < 0.001) differences in serum 25(OH)D levels between age groups in the female patients. The concentrations were lowest in patients in their twenties (25.1 +/- 8.2 nmol/l) and highest in patients in their fifties and sixties (43.2 +/- 13.7 nmol/l). Serum 25(OH)D concentrations might be monitored in patients with Graves' disease during antithyroid drug therapy, and vitamin D and/or calcium supplements are recommended for patients with vitamin D deficiency.

Adolescent↗