Histopathological criteria for assessment of therapeutic response in breast cancer.
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Breast Neoplasms↗
Biomedical subjects
M Okazaki
Publications and source records attributed to M Okazaki.
Extracellular-superoxide dismutase in cerebrospinal fluid from infants/children.
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Adolescent↗
Affinity binding phenomena of DNA onto apatite crystals.
The effect of DNA on the crystal growth of hydroxyapatite (HAp) and its morphology was examined. X-ray diffraction patterns of DNA-containing apatites showed typical apatitic features. However, crystal growth was greatly inhibited in the presence of DNA during synthesis; particularly, the crystallinity in the a-axis direction decreased dramatically at low concentrations of DNA. The a- and c-axis dimensions of each precipitate were almost the same, which implies that DNA molecules affect only the crystal surface. CHN analysis clearly showed the presence of these elements, which increased with an increase in DNA concentration in the solution. Scanning electron micrographs of the precipitates formed in the presence of DNA showed typical needle-like crystals, with a decreased crystal size, especially width. Infrared absorption spectroscopy of the DNA-containing apatites showed that the 1630-1700 cm(-1) absorption band due to C=C and C=N stretching increased with an increase in DNA concentration during precipitation. The ESCA spectrum of HAp(DNA 1.0) shows N 1s and C 1s peaks that are absent and weak, respectively in HAp. 31P NMR spectroscopy revealed a weak peak at the base of the 31P peak from the PO4(3-) ions in the HAp crystals. This weak 31P peak had a small positive shift from the position found in native DNA which may be due to the phosphate backbone of adsorbed DNA. The apparent solubility of the HAps increased with an increase in DNA concentration. These results suggest that there is an affinity binding between apatite crystal and DNA molecules.
Animals↗
Plant hormone regulation on scopoletin metabolism from culture medium into tobacco cells.
Tobacco (Nicotiana tabacum L. Bright Yellow) T-13 cell line has an ability for production of scopoletin. In this cell culture, scopoletin is taken up from culture medium and accumulated in vacuoles after conversion to scopolin when cells are treated with 2,4-dichlorophenoxyacetic acid (2,4-D) (Taguchi et al. (2000)). To clarify the effect of 2,4-D on tobacco cells, its interaction with several other plant hormones was investigated. Other auxins also stimulated the uptake in the same manner as 2,4-D did, although higher concentrations were required than that of 2,4-D. When p-chlorophenoxyisobutyric acid (PCIB), an antiauxin, was added to the cell culture before 2,4-D, it inhibited 2,4-D-stimulated scopoletin uptake. This result suggests that the stimulation of scopoletin uptake was one of the auxin effects on tobacco cells. Among other classes of plant hormones that were tested, only salicylic acid stimulated the uptake. When these hormones were added to the cell cultures before 2,4-D, methyl jasmonate and kinetin reduced scopoletin uptake. These results suggest that this scopoletin uptake by tobacco cells is regulated by the interaction between different plant hormones.
Journal Article↗
Effects of all-trans retinoic acid on melanogenesis in pigmented skin equivalents and monolayer culture of melanocytes.
The effects of all-trans retinoic acid (RA) on melanogenesis and the mechanism of its action in topical treatment have not been elucidated. The purpose of this study was to determine the effects of RA on melanogenesis in the pigmented skin equivalent as well as in monolayer culture of melanocytes, and to determine whether RA, hydroquinone (HQ), and hydrocortisone (HC) show synergistic depigmenting effects in combined treatments of each other. The suppressing effect of RA on melanogenesis was not observed in pigmented skin equivalents and monolayer culture of murine and human melanocytes, although HQ showed strong inhibition of melanogenesis. The synergistic effects between RA, HQ, and HC were not particularly seen. The results suggested that RA neither has direct inhibitory effects on melanogenesis of melanocytes, nor influences the cell-cell interactions between melanocytes, keratinocytes and fibroblasts, such as paracrine actions with regard to melanin production. The role of RA in bleaching treatments appears to be in other specific actions, such as promotion of keratinocytes proliferation and acceleration of epidermal turnover.
Animals↗
Convenient synthesis of aliphatic polyesters by distannoxane-catalyzed polycondensation.
A convenient synthesis of aliphatic polyesters by the distannoxane-catalyzed polycondensation of aliphatic dicarboxylic acids and aliphatic diols in solvents under azeotropic conditions was developed. To determine the optimum conditions for polycondensation of succinic acid with 1,4-butandiol, the effect of various types of catalyst and their concentration was investigated. By choosing the appropriate solvent, the polymerization was made to proceed in a two-phase system of solvent and molten polymer, and in the presence of 0.001 mol % of 1-chloro-3-hydroxy-1,1,3,3-tetrabutyldistannoxane (CHTD), poly(butylene succinate) (PBS) with a weight-average molecular weight of 277,000 was obtained. This method was then successfully applied to the synthesis of various aliphatic polyesters, such as poly(ethylene succinate), poly(1,4-cyclohexanedimethylene succinate), and poly(ethylene sebacate).
Biodegradation, Environmental↗
Studies on cytotoxic effect of nickel ions on three cultured fibroblasts.
Cytotoxicity of Ni ions on three fibroblasts such as L929, Balb/3T3 clone A31 and MC3T3-E1 were examined by cell count (CC) and Neutral Red assay (NR). Three cells were incubated for 6 days in 1 ml DME medium containing Ni ions which ranged from 0 to 2 mM/l. The results clarified that Ni ions had dose-dependent cytotoxicity. L929 possessed the largest TC50 values (the amount of Ni ion that caused 50% cell death or 50% cell viability) of 0.12 mM/l (CC) and 0.32 mM/l (NR), and Balb/3T3 clone A31 had the least values of 0.05 mM/l (CC) and 0.09 mM/l (NR), whilst MC3T3-E1 had the intermediate values of 0.08 mM/l (CC) and 0.15 mM/l (NR). The dissolution of Ni ions from Ni-containing metallic restorations must be lower than these concentration levels so that body tissues might not be severely damaged.
Journal Article↗
Molecular cloning and heterologous expression of novel glucosyltransferases from tobacco cultured cells that have broad substrate specificity and are induced by salicylic acid and auxin.
Scopoletin is one of the phytoalexins in tobacco. Cells of the T-13 cell line (Nicotiana tabacum L. Bright Yellow) accumulate a large amount of scopoletin, also known as 7-hydroxy-6-methoxycoumarin, as a glucoconjugate, scopolin, in vacuoles. We report here the molecular cloning of glucosyltransferases that can catalyze the glucosylation of many kinds of secondary metabolites including scopoletin. Two cDNAs encoding glucosyltransferase (NtGT1a and NtGT1b) were isolated from a cDNA library derived from the tobacco T-13 cell line by screening with heterologous cDNAs as a probe. The deduced amino-acid sequences of NtGT1a and NtGT1b exhibited 92% identity with each other, approximately 20-50% identities with other reported glucosyltransferases. Heterologous expression of these genes in Escherichia coli showed that the recombinant enzymes had glucosylation activity against both flavonoids and coumarins. They also strongly reacted with 2-naphthol as a substrate. These recombinant enzymes can utilize UDP-glucose as the sugar donor, but they can also utilize UDP-xylose as a weak donor. RNA blot analysis showed that these genes are induced by salicylic acid and auxin, but the time course of the expression was different. This result is similar to the changes in scopoletin glucosylation activity in these tobacco cells after addition of these plant growth regulators. These results might suggest that one of the roles of the products of these genes is scopoletin glucosylation, in response to salicylic acid and/or auxin, together with the other glucosyltransferases in tobacco cells.
Amino Acid Sequence↗
Focal nodular hyperplasia treated by transcatheter arterial embolization using Lipiodol mixed with Gelfoam particles.
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Adolescent↗
Pressure-induced expression of monocyte chemoattractant protein-1 through activation of MAP kinase.
BACKGROUND: In glomerular hypertension, mesangial cells (MC) are subjected to at least two physical forces: a high pressure and mechanical stretch. In 5/6 nephrectomized rat, a model of progressive glomerular sclerosis associated with glomerular hypertension, monocyte chemoattractant protein-1 (MCP-1) is expressed in glomeruli, suggesting the possible role of MCP-1 in the pathogenesis of glomerular sclerosis; however, whether pressure directly affects MCP-1 expression remains undetermined. Here we examined the effects of pressure on MCP-1 expression in cultured rat MC and the signal transduction pathways that lead to MCP-1 expression. METHODS: Pressure was applied to MC by instilling compressed helium gas into sealed plates. MCP-1 mRNA and protein levels in MC were detected by reverse transcription-polymerase chain reaction (RT-PCR) or Northern blotting and ELISA or Western blotting, respectively. Mitogen-activated protein (MAP) kinase activity was measured with the catalytic activity of p42/p44 MAP kinase and anti-phospho p42/p44 MAP kinase antibody. A transient transfection assay that specifically modulates MAP kinase kinase (MEK) activity was carried out. RESULTS: MCs subjected to external pressure expressed MCP-1 mRNA rapidly and transiently with the peak level noted at 10 minutes and 80 mm Hg pressure. MCP-1 protein levels in cell lysates and culture medium also significantly increased after pressure loading. Pressure rapidly increased the phosphorylation level and activity of p42/p44 MAP kinase. Treatment of MC with a MAP kinase kinase (MEK) inhibitor, PD98059, suppressed levels of both pressure-induced MAP kinase activities and MCP-1 mRNA expression. The constitutively activated type of MEK1 induced MCP-1 expression (13.7-fold) even in non-pressurized MC. CONCLUSIONS: Our results indicate that pressure per se can induce MCP-1 via activation of MAP kinase pathway, suggesting that glomerular hypertension might be involved in the progression of renal diseases through the expression of MCP-1 in MC.
Animals↗
Dietary medium-chain triacylglycerols suppress accumulation of body fat in a double-blind, controlled trial in healthy men and women.
We investigated the effect of long-term ingestion of dietary medium-chain triacylglycerols (MCT) on body weight and fat in humans. Using a double-blind, controlled protocol, we assessed the potential health benefits of MCT compared with long-chain triacylglycerols (LCT) in 78 healthy men and women [body mass index (BMI) > or = 23 kg/m(2): n = 26 (MCT), n = 30 (LCT); BMI < 23 kg/m(2): n = 15 (MCT), n = 7 (LCT)]. Changes in anthropometric variables, body weight and body fat during the 12-wk MCT treatment period were compared with those in subjects consuming the LCT diet. The subjects were asked to consume 9218 kJ/d and 60 g/d of total fat. The energy, fat, protein and carbohydrate intakes did not differ significantly between the groups. Body weight and body fat in both groups had decreased by wk 4, 8 and 12 of the study. However, in the subjects with BMI > or = 23 kg/m(2), the extent of the decrease in body weight was significantly greater in the MCT group than in the LCT group. In subjects with BMI > or = 23 kg/m(2), the loss of body fat in the MCT group (-3.86 +/- 0.3 kg) was significantly greater than that in the LCT group (-2.75 +/- 0.2 kg) at 8 wk. In addition, in subjects with BMI > or = 23 kg/m(2), the decrease in the area of subcutaneous fat in the MCT group was significantly greater than that in the LCT group at wk 4, 8 and 12. These results suggest that the MCT diet may reduce body weight and fat in individuals (BMI > or = 23 kg/m(2)) more than the LCT diet.
Adipose Tissue↗
Tattoo removal by grafting enzymatically separated epidermis.
A novel method of tattoo removal in which the enzymatically separated epidermis of an excised tattoo was grafted in situ was applied to 3 patients. Unlike the conventional skin-grafting procedure, this method resulted in the complete obliteration of the tattoos without donor site scars. In 1990, Hosokawa and colleagues first reported a technique similar to the one described, but the enzymatic process required surgery to be performed over two consecutive days and, thus, it did not become an established procedure. A modification of Hosokawa's method enabled the authors to reduce the enzymatic processing time to an hour using Dispase. The thinning of the tattooed skin using a Paget's-type dermatome before its exposure to an enzymatic solution facilitated the enzyme's infiltration of the basal layer of the epidermis. Hence, the time taken for the epidermis to separate from the tattooed skin was markedly shortened. Although laser removal continues to be the optimal treatment method, skin grafting or other abrasive procedures, including dermabrasion and cryosurgery, are still necessary for those patients who want complete tattoo obliteration over a shorter time frame and at less expense. In these patients the authors recommend that their procedure be offered as an alternative treatment to laser removal.
Adult↗
Synergistic interaction of integrin and angiotensin II in activation of extracellular signal-regulated kinase pathways in vascular smooth muscle cells.
Integrins, major adhesion receptors and angiotensin II activate extracellular signal-regulated kinase (ERK) pathways and result in a mitogenic response such as the proliferation of vascular smooth muscle cells (VSMCs). We investigated mechanisms of collaboration or synergism between integrins and angiotensin II involving ERK pathways in VSMCs. Integrin activation by cell adhesion to fibronectin increased the phosphorylation level of focal adhesion kinase (FAK) upstream of the ERK pathway. angiotensin II induced a high increase in the phosphorylation level of FAK with integrin activation, but not in suspended cells. Integrin activation increased phosphorylation levels of ERK kinase (MEK) and ERK phosphorylation as well. Angiotensin II-induced MEK and ERK phosphorylation were retained even in suspended cells. Furthermore, with integrin activation, angiotensin II induced a much larger increase in the phosphorylation levels of MEK and ERK. These results suggest that simultaneous stimulation of integrin and angiotensin II receptors cause synergistic interaction in the activation of ERK pathway, possibly via phosphorylation of FAK, which may play a critical role in angiotensin II-mediated mitogenic response in VSMCs.
Angiotensin II↗
Effect of probucol in lecithin-cholesterol acyltransferase-deficient mice: inhibition of 2 independent cellular cholesterol-releasing pathways in vivo.
Cellular cholesterol release takes place by at least 2 distinct mechanisms: the lecithin-cholesterol acyltransferase (LCAT)-driven net efflux by cholesterol diffusion and the generation of high density lipoprotein (HDL) with cellular cholesterol and phospholipid on the cell-apolipoprotein interaction. Therefore, LCAT deficiency impairs the former pathway, and the latter can be inhibited by probucol, which interferes with the apolipoprotein-cell interaction. Hence, probucol was given to the LCAT-deficient mice in the attempt to suppress both of these pathways. The mice were fed low (0.2%) and high (1.2%) cholesterol diets containing 0.5% probucol for 2 weeks. LCAT deficiency and probucol markedly decreased plasma HDL, and the effects were synergistic. Tissue cholesterol content was lower in the adrenal glands and ovaries in the LCAT-deficient mice and in the probucol-treated mice, suggesting that HDL is a main cholesterol provider for these organs. It was also moderately decreased in the spleen of the low cholesterol-fed female mice and in the thyroid gland of the low cholesterol-fed male mice. On the other hand, the esterified cholesterol content in the liver was substantially increased by the probucol treatment with a high cholesterol diet in the LCAT-deficient mice but not in the wild-type mice. Among the groups, there was no significant difference in the tissue cholesterol levels in other organs, such as the liver, spleen, thymus, brain, erythrocytes, thyroid gland, testis, and aorta, resulting from either LCAT deficiency or probucol. Thus, the apolipoprotein-mediated mechanism plays a significant role in the export of cellular cholesterol in the liver, indicating that the liver is a major site of the HDL assembly. Otherwise, tissue cholesterol homeostasis can largely be maintained in mice even when the assembly of new HDL is inhibited by probucol in the absence of LCAT. Nonspecific diffusion of cholesterol perhaps adequately maintains the homeostasis in the experimental condition.
Animals↗
Adhesion to and decalcification of hydroxyapatite by carboxylic acids.
Fundamental to the processes of decalcification of or adhesion to mineralized tissues is the molecular interaction of acids with hydroxyapatite. This study was undertaken to chemically analyze the interaction of 1 mono-, 2 di-, 1 tri-, and 2 polycarboxylic acids with hydroxyapatite in an attempt to elucidate the underlying mechanism. Maleic, citric, and lactic acid decalcified hydroxyapatite, in contrast to oxalic acid and the two polycarboxylic acids that were chemically bonded to hydroxyapatite. Solubility tests showed that the calcium salts of the former were very soluble, whereas those of the latter could hardly be dissolved in the respective acid solutions. Based on these data, an adhesion/decalcification concept was advanced that predicts that carboxylic acids, regardless of concentration/pH, either adhere to or decalcify hydroxyapatite, depending on the dissolution rate of the respective calcium salts in the acid solution. This contrasting behavior of organic acids most likely results from their differential structural conformations.
Acrylic Resins↗
Effect of long term-administration with Gymnema sylvestre R. BR on plasma and liver lipid in rats.
Extract of Gymnema sylvestre leaves was administered to rats receiving either a high fat diet or normal fat diet for 10 weeks to investigate its influence on plasma and liver lipids and on visceral fat accumulation. In addition, its effect was compared with those of chitosan and the influence of combined use of these two substances was also evaluated. Within the high fat diet groups, the extract suppressed body weight gain and accumulation of liver lipids to the same extent as chitosan and the combined use. In addition, intraperitoneal fat and fat drop vacuoles on the epithelium of renal tubules, noted in the high fat diet group, were scattered by administration of the extract with the same results as for chitosan and combined use. Within the normal fat diet groups, plasma triglyceride levels decreased by administration of the extract, with similar results as chitosan and combined use. Concerning plasma total cholesterol, there was no decreasing effects with the extract, as found with chitosan and combined use. However, the effect of chitosan on plasma total cholesterol tended to be enhanced when used in combination with the extract. In addition, long-term administration of the extract did not show any influence on hematological and blood chemical parameters.
Animals↗
Effect of administration with the extract of Gymnema sylvestre R. Br leaves on lipid metabolism in rats.
Extract of Gymnema sylvestre R. Br leaves (GE) was orally administered once a day to rats fed a high fat diet or normal fat diet for 3 weeks to investigate its influence on lipid metabolism. As a result, GE did not influence body weight gain or feed intake in both diet groups during the experimental period. The apparent fat digestibility was significantly decreased by GE in both diet groups for the last 2 weeks of the experimental period, though not the apparent protein digestibility. In addition, the excretion of neutral sterols and acid steroids into feces was increased by GE in both diet groups. Furthermore, GE decreased the total cholesterol and triglyceride levels in serum. On the other hand, blood lecithin-cholesterol acyltransferase (LCAT) activity was increased by GE. Moreover, it was suggested that GE influenced cecal fermentation and that propionic acid and acetic acid contents in cecum were significantly increased by GE. Consequently, it was suggested that GE improved serum cholesterol and triglyceride levels through influence over a wide range of lipid metabolism in rats.
Animals↗
The bacterium Burkholderia gladioli strain CHB101 produces two different kinds of chitinases belonging to families 18 and 19 of the glycosyl hydrolases.
Two genes (chiA and chiB) coding for chitanases A and B (ChiA and ChiB) were isolated from the chitinolytic bacterium, Burkholderia gladioli strain CHB101. chiA contains an open reading frame that encodes a protein of 343 amino acids, whereas chiB encodes a protein of 307 amino acids. The deduced amino acid sequence of ChiA showed a high similarity to those of microbial chitinases belonging to family 18 of the glycosyl hydrolases, while ChiB showed significant sequence similarity to plant chitinases and Streptomyces spp. chitinases belonging to family 19.
Journal Article↗