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Biomedical subjects

Takayuki Shibamoto

Publications and source records attributed to Takayuki Shibamoto.

At least 19 recordsLinked to original sources

Quantitation of volatiles and nonvolatile acids in an extract from coffee beverages: correlation with antioxidant activity.

The antioxidant activities of a commercial brewed coffee were investigated by measuring malonaldehyde (MA) formation from oxidized cod liver oil using a gas chromatographic method (MA-GC assay) and a thiobarbituric acid method (TBA assay). The highest antioxidant activity obtained by the MA-GC assay was from regular whole brewed coffee (97.8%) at a level of 20%, and the highest antioxidant activity obtained by the TBA assay was from decaffeinated whole brewed coffee (96.6%) at a level of 5%. Among 31 chemicals identified in a dichloromethane extract, guaiacol, ethylguaiacol, and vinylguaiacol exhibited antioxidant activities, which were comparable to that of alpha-tocopherol. Among nine chlorogenic acids (three caffeoylquinic acids, three feruloylquinic acids, and three dicaffeoylquinic acids) identified, 5-caffeoylquinic acid contained the greatest amount both in regular (883.5 microg/mL) and in decaffeinated (1032.6 microg/mL) coffees; it exhibited 24.5% activity by the MA-GC assay and 45.3% activity by the TBA assay at a level of 10 microg/mL. Caffeic and ferulic acids showed moderate antioxidant activities in both assays.

Acids, Carbocyclic↗

Partial purification from hot dogs of N-nitroso compound precursors and their mutagenicity after nitrosation.

Hot dogs contain apparent N-nitroso compounds (ANC) and ANC precursors (ANCP). ANCP purification was followed by nitrosation, sulfamic acid treatment, and analysis for ANC. Aqueous hot dog extracts were adsorbed on silica gel, which was eluted with MeCN and MeOH. The MeOH eluate was adsorbed on cation exchange resin (H+ form) and eluted with NH4OH. Eluted ANCP traveled at moderate speeds in high-performance liquid chromatography (HPLC) on amino and Pb2+ columns. Gas chromatography-mass spectrometry (GC-MS) of trimethylsilyl (TMS) derivatives of crude water extract indicated the presence of glycerol, phosphate, lactic acid, and two monosaccharides. GC-MS of TMS derivatives of Pb2+ column HPLC eluates indicated that ANCP included 1-deoxy-N-1-glucosyl glycine. The nitrosated NH4OH eluate showed 4x background mutagenic activity for Salmonella typhimurium TA-100. Un-nitrosated fractions showed 2x background activity. Although tryptophan nitrosation gave 88% ANC yield, tryptophan is probably not a major ANCP in hot dogs. Hot dog patties prepared with or without sucrose or glucose showed similar ANC and ANCP levels. We discuss possible implications of these findings for the etiology of colon cancer.

Amino Acids↗

Pesticide detoxifying functions of N-halamine fabrics.

Halamine structures incorporated on polyester/cotton fabrics were able to detoxify oxime carbamate pesticides that contain thio bonds rapidly upon contact. The reaction was endothermic, and the detoxification rate was in first order to concentrations of the pesticides. Aldicarb was degraded in a much faster rate than that of methomyl by the halamine fabrics. The reactivity of halamine structures was different, and imide halamine was more reactive than amine halamine. The detoxification was an oxidative reaction on the sulfur atom existing in both aldicarb and methomyl. The same halamine structures were unable to effectively react with carbaryl and carbofuran, which are aromatic carbamates and do not contain any thio bonds.

Aldicarb↗

Determination of toxic carbonyl compounds in cigarette smoke.

Toxic carbonyl compounds, including formaldehyde, malonaldehyde, and glyoxal, formed in mainstream cigarette smoke were quantified by derivatization-solid phase extraction-gas chromatography methods. Cigarette smoke from 14 commercial brands and one reference (2R1F) was drawn into a separatory funnel containing aqueous phosphate-buffered saline. Reactive carbonyl compounds trapped in the buffer solution were derivatized into stable nitrogen containing compounds (pyrazoles for beta-dicarbonyl and alpha,beta-unsaturated aldehyde; quinoxalines for alpha-dicarbonyls; and thiazolidines for alkanals). After derivatives were recovered using C(18) solid phase extraction cartridges, they were analyzed quantitatively by a gas chromatograph with a nitrogen phosphorus detector. The total carbonyl compounds recovered from regular size cigarettes ranged from 1.92 mg/cigarette(-1) to 3.14 mg/cigarette(-1). The total carbonyl compounds recovered from a reference cigarette and a king size cigarette were 3.23 mg/cigarette(-1) and 3.39 mg/cigarette(-1), respectively. The general decreasing order of the carbonyl compounds yielded was acetaldehyde (1110-2101 microg/cigarette(-1)) > diacetyl (301-433 microg/cigarette(-1)), acrolein (238-468 microg/cigarette(-1)) > formaldehyde (87.0-243 microg/cigarette(-1)), propanal (87.0-176 microg/cigarette(-1)) > malonaldehyde (18.9-36.0 microg/cigarette(-1)), methylglyoxal (13.4-59.6 microg/cigarette(-1)) > glyoxal (1.93-6.98 microg/cigarette(-1)).

Air Pollutants↗

Enhancement of mite allergen-induced eosinophil infiltration in the murine airway and local cytokine/chemokine expression by Asian sand dust.

Data on the effects of sand dust toward allergic asthma produced by indoor allergens, such as house dust mites, are not currently available. This study was undertaken to clarify the role of Asian sand dust on mite allergen, Dermatophagoides farinae (D. farinae)-induced eosinophilic inflammation in the murine lung, using sand dusts from the Maowusu Desert (Inner Mongolia) (SD-1) and the Tengger Desert (China) (SD-2). ICR mice were intratracheally administered saline; SD-1 alone; SD-2 alone; D. farinae alone; D. farinae + SD-1; and D. farinae + SD-2, 4 times at 2-wk intervals. The two sand dusts enhanced infiltration of eosinophil in the airway, along with goblet-cell proliferation related to D. farinae. The degree of eosinophil infiltration induced with SD-2 was greater than with SD-1. The SD-1, which contained higher amounts of beta-glucan, increased the expression of interferon (IFN)-gamma in bronchoalveolar lavage fluids (BALF) with or without D. farinae, but SD-2 did not. Synergistically or cumulatively elevated levels of interleukin (IL)-5, eotaxin, and monocyte chemotactic protein in BALF related to D. farinae were higher with D. farinae + SD-2 than with D. farinae + SD-1. These results suggest that increased cytokine and chemokines in BALF play an important role in the enhancement of eosinophil infiltration in the airway induced by D. farinae + sand dusts. The reduced eosinophil infiltration in the SD-1-treated mice could be due to suppression of Th-2 cytokine and eotaxin via interferon-gamma induced by microbial materials, such as beta-glucan.

Animals↗

Formation of dioxins from combustion of polyvinylidene chloride in a well-controlled incinerator.

Polyvinylidene chloride (PVDC; polymer of 1,1-dichloroethylene) was combusted with paper in a well-controlled, small-scale incinerator at an average grate temperature of 700 degrees C, and then dioxins (PCDDs, PCDFs, and coplanar-PCBs) formed in the exhaust gases were analyzed by gas chromatography/mass spectrometry. PVDC lowered the combustion temperature due to its less flammable character. The amount of total dioxins (PCDDs+PCDFs+coplanar-PCBs) formed in the exhaust gas was 58.0 ng/g of a combustion sample and its toxicity equivalency quantity (TEQ) value was 0.64 ng-TEQ/g. The amount of PCDDs formed in the sample ranged from 2.33 ng/g (Cl(8)-isomer) to 0.048 ng/g (Cl(1)-isomer). The lower the number of chloride, the less production of PCDDs. On the other hand, there was no relation between the number of chloride and PCDF formation. The amount of PCDFs formed in the sample ranged from 8.02 ng/g (Cl(2)-isomer) to 4.46 ng/g (Cl(8)-isomer). A polyvinylchloride (PVC) sample produced 207 ng/g of total dioxins and a PVDC sample produced 57.4 ng/g of total dioxins when they were combusted under the same conditions. An approximately equal composition of dioxin isomers was formed from PVDC and PVC samples. Paper was found to contribute to PCDF formation when it was combusted with plastics.

Air Pollutants↗

Correlation of acrylamide generation in thermally processed model systems of asparagine and glucose with color formation, amounts of pyrazines formed, and antioxidative properties of extracts.

The relations between the formation of acrylamide and color, pyrazines, or antioxidants in an asparagine/d-glucose browning model system under various conditions were investigated. The highest level of acrylamide was produced in the asparagine/glucose (1:3) system heated at 170 degrees C for 30 min (2629 microg/g asparagine). Color intensity increased with temperature and heating time. The formation of pyrazines increased steadily with an increase of temperature (140-170 degrees C) and heating time (15-60 min). Antioxidant formation varied among the samples heated under different conditions. A clear correlation between formation of acrylamide and browning color was obtained. The formation of acrylamide was linearly correlated with the formation of total pyrazines during the initial stages of the Maillard reaction. No obvious correlation between formation of acrylamide and antioxidants was observed. However, excess amounts of asparagine increased the formation of antioxidants, whereas excess amounts of glucose reduced its formation.

Acrylamides↗

Improved malonaldehyde assay using headspace solid-phase microextraction and its application to the measurement of the antioxidant activity of phytochemicals.

A modified malonaldehyde (MA) assay for antioxidant activity, which involves derivatization and headspace solid-phase microextraction (HS-SPME) was developed and validated. The recovery of MA as 1-methylpyrazole (product of MA and N-methylhydrazine) from a headspace of an aqueous solution containing MA, buffer, surfactant, and cod liver oil using HS-SPME with a PDMS/DVB fiber was 91.3 +/- 3.38%. MA was analyzed by a gas chromatograph with a nitrogen-phosphorus detector, and its detection limit was 0.0103 nmol/mL. The antioxidant activities of natural compounds were determined as the percentage inhibition of MA formed from cod liver oil oxidized by Fenton's reagents in the above aqueous solution. Sesamol inhibited MA formation most (86.1%), followed by eugenol (84.4%), capsaicin (80.7%), ethylvanillin (45.3%), and vanillin (31.6%) at a level of 50 microg/mL. This method did not require any organic solvents and is a simple, fast, and a highly sensitive method for MA determination.

Antioxidants↗

Investigation of methyl tert-butyl ether levels in river-, ground-, and sewage-waters analyzed using a purge-and-trap interfaced to a gas chromatograph-mass spectrometer.

River water collected from 27 sites in 21 rivers, groundwater from 66 sites in 34 cities, and 2 sewage plants in the Niigata Prefecture, Japan (total 301 samples) were analyzed for methyl tert-butyl ether (MTBE) using an improved purge-and-trap-GC-MS method. The amount of MTBE found in water samples from the 27 river sites ranged from 0.003 to 5.3 microg l(-1). MTBE was found in all 27 sites during winter but it was found at only 9 sites and 14 sites, respectively, during the summer. MTBE was found most frequently (in 21 sites) at levels ranging from 0.003 to 0.009 microg l(-1) during February. The highest levels of MTBE were always found in the samples collected from the same site. The amount of MTBE found in sewage water samples ranged from <0.003 to 0.025 microgl(-1). No significant differences were observed between the amounts of MTBE recovered from inflow and outflow waters. Relatively high levels (0.02-0.034 microg l(-1) ) of MTBE were found in January at two sites, which were located on the upper course of the Shinano River. MTBE levels ranged from 0.004 to 0.035 microgl(-l) and from 0.005 to 0.041 microgl(-1) at the mouths of the Shinano River and Agano River, respectively. The levels of MTBE in groundwater collected from 66 sites in 34 cities in Niigata Prefecture ranged from <0.003 to 5.9 microg l(-1).

Carcinogens, Environmental↗

Formation of acrylamide from lipids.

Heating amino acids with dietary oils or animal fats at elevated temperatures produced various amounts of acrylamide. The amount of acrylamide formation corresponded to the degree of unsaturation of the oils and animal fats. The decreasing order of acrylamide formation from dietary oils or animal fats with asparagine was sardine oil (642 microg/g asparagine) > cod liver oil (435.4 microg/g) > soybean oil (135.8 microg/g) > corn oil (80.7 microg/g) > olive oil (73.6 microg/g) > canola oil (70.7 microg/g) > corn oil (62.1 microg/g) > beef fat (59.3 microg/g) > lard (36.0 microg/g). Three-carbon unit compounds such as acrylic acid and acrolein, which are formed from lipids by oxidation also produced acrylamide by heat treatment with amino acids, in particular with asparagine. The results of the present study suggest that acrylamide forms in asparagine-rich foods during deep fat frying in the absence reducing sugars.

Acrolein↗

The role of metals in dioxin formation from combustion of newspapers and polyvinyl chloride in an incinerator.

Newspapers impregnated with NaCl mixed with various chloride metals (CuCl2, MgCl2, MnCl2, FeCl3, NiCl2, and CoCl2) and electric wire coated with polyvinyl chloride (PVC) were combusted in a well-controlled incinerator. Exhaust gas samples collected at the outlet of the incinerator were analyzed for dioxins (PCDDs, PCDFs, and coplanar PCBs) by gas chromatography/mass spectrometry. The amount of total dioxins formed from newspaper samples ranged from 34.2 ng/g (with NaCl+CoCl2) to 67.0 ng/g (with NaCl+CuCl2). PCDFs composed 88-94% of the total dioxins formed in the exhaust gases. The highest levels of PCDF isomers obtained were Cl3-CDF from the sample with NaCl+CuCl2 (14.8 ng/g), Cl2-CDF from the sample with NaCl+MgCl2 (12.3 ng/g), and Cl(1)-CDF from samples with NaCl+MnCl2 (12.6 ng/g), with NaCl+FeCl3 (11.8 ng/g), and with NaCl+NiCl2 (13.3 ng/g), and with NaCl+CoCl2 (8.62 ng/g). The total of Cl4-8-CDDs comprised 76-88% of the total Cl1-8-CDDs. In particular, Cl7-CDDs had the highest levels except for the sample with NaCl+NiCl2. Total dioxins formed from samples of electric wire coated with PVC and PVC alone were 38.3 ng/g and 112 ng/g, respectively, suggesting that the presence of copper reduced dioxin formation.

Dioxins↗

Asian sand dust enhances ovalbumin-induced eosinophil recruitment in the alveoli and airway of mice.

Asian sand dust (ASD) containing sulfate (SO4(2-)) reportedly causes adverse respiratory health effects but there is no experimental study showing the effect of ASD toward allergic respiratory diseases. The effects of ASD and ASD plus SO4(2-) toward allergic lung inflammation induced by ovalbumin (OVA) were investigated in this study. ICR mice were administered intratracheally with saline; ASD alone (sample from Shapotou desert); and ASD plus SO4(2-) (ASD-SO4); OVA+ASD; OVA+ASD-SO4. ASD or ASD-SO4 alone caused mild nutrophilic inflammation in the bronchi and alveoli. ASD and ASD-SO4 increased pro-inflammatory mediators, such as Keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-1 alpha, in bronchoalveolar lavage fluids (BALF). ASD and ASD-SO4 enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. However, a further increase of eosinophils by addition of SO4(2-) was not observed. The two sand dusts synergistically increased interleukin-5 (IL-5) and monocyte chemotactic protein-1 (MCP-1), which were associated with OVA, in BALF. However, the increased levels of IL-5 were lower in the OVA+ASD-SO4 group than in the OVA+ASD group. ASD caused the adjuvant effects to specific-IgG1 production by OVA, but not to specific-IgE. These results suggest that the enhancement of eosinophil recruitment in the lung is mediated by synergistically increased IL-5 and MCP-1. IgG1 antibodies may play an important role in the enhancement of allergic reaction caused by OVA and sand dust. However, extra sulfate may not contribute to an increase of eosinophils.

Animals↗

A-role of alkaline elements in formation of PCDDs, PCDFs, and coplanar PCBs during combustion of various paper samples.

Combustion of industrial and domestic wastes produces significant amounts of dioxins (PCDDs, PCDFs, and coplanar PCBs). These wastes contain numerous kinds of materials, including inorganic elements, which may play an important role in dioxin formation upon combustion. Six paper samples--impregnated with NaHCO3, NaCl + fly ash, polyvinyl chloride (PVC), and PVC + NaHCO3--were combusted in a well-controlled incinerator at 512-760 degrees C and exhaust gases were analyzed for dioxins (PCDDs, PCDFs, and coplanar PCBs). Addition of fly ash, which contained high levels of Ca and Cl, to NaCl impregnated-newspaper increased total dioxin formation from 80.8 ngg(-1) to 139 ngg(-1) during combustion. Addition of NaHCO3 to PVC-impregnated newspaper increased total dioxin formation from 220 ngg(-1) to 288 ngg(-1). Formation of PCDDs from NaHCO3/PVC-impregnated newspaper were significantly less than that from newspaper impregnated with PVC alone. On the other hand, more PCDFs formed from NaHCO3/PVC-impregnated newspaper than from newspaper impregnated with PVC alone. Addition of NaHCO3 to a PVC-impregnated newspaper changed the production pattern of dioxins. PVC- impregnated newspaper produced the greatest amount of coplanar PCBs (12.3 ngg(-1)), which may be accounted for by the relatively high level of TEQ value (3.31 ng-TEQg(-1)) of this sample. Generally, addition of fly ash and alkali metals, such as Na, to paper samples increased the total dioxin formation in exhaust gases during combustion. The results suggest that alkali metals increase Cl concentrations at a reaction site by trapping chloride ions and/or chloride radicals and consequently increasing dioxin formation.

Air Pollutants↗

Degradation of malathion, in aqueous extracts of asparagus (Asparagus officinalis).

Malathion was incubated in water extracts of vegetables at various temperatures and pH, and the amount of malathion present over time was analyzed by a gas chromatograph with a flame photometric detector. Malathion was degraded to a nondetectable level in a 1% asparagus extract incubated at pH 7.4 and 37 degrees C for 4 h. Carrot extract showed the second highest rate of malathion degradation (76%), followed by kale extract (23.7%), spinach extract (9.7%), and broccoli extract (1.5%) under the same conditions. The highest degradation rates of malathion were observed at 37 degrees C, when three different temperatures were tested (5, 25, and 37 degrees C) at pH 7.4. Rate constants were 0.134 min(-)(1) from a 1% asparagus solution and 0.095 min(-)(1) from a 0.5% asparagus solution. The highest degradation rate of malathion was achieved at pH 9 among the pHs tested (pH 4, 7.4, and 9) in a 0.5% asparagus solution. The 0.5% asparagus solution degraded dicarboxylic acid esters by almost 100% for dimethyl succinate and diethyl adipate, by 64% for diethyl acetyl succinate, and 30% for diethyl benzyl malonate when incubated at pH 9 for 20 min. The results support the hypothesis that the enzyme that degrades malathion in the asparagus solutions is a carboxylesterase.

Asparagus Plant↗

Inhibition of malonaldehyde formation in oxidized calf thymus DNA with synthetic and natural antioxidants.

Calf thymus DNA was oxidized by Fenton's reagent with or without synthetic antioxidants (Trolox and DMPO) and natural antioxidants-quercetin, apigenin, 2''-O-glycosylisovitexin (2''-O-GIV), (+)-catechin, cyanidin, pelargonidin, keracyanin, and callistephin. Malonaldehyde (MA) formed in oxidized DNA was analyzed using gas chromatography. MA formed from oxidized DNA without antioxidants was 4.0 +/- 0.53 nmol/mg of DNA in buffer solution, 3.7 +/- 0.34 nmol/mg of DNA in NaOH solution, and 4.6 +/- 0.19 nmol/mg of DNA in HCl solution. MA formed from DNA with antioxidants (at the level of 0.1 micromol/mL) ranged from 1.90 +/- 0.18 (catechin) to 4.10 +/- 0.18 nmol/mg of DNA (cyanidin). Trolox and DMPO inhibited MA formation from DNA by 41.2% and 18.6%, respectively, at the level of 0.1 micromol/mL. Trolox (water-soluble vitamin E) exhibited dose-dependent inhibition. The decreasing order of inhibitory effect by flavonoids at the level of 0.1 micromol/mL was catechin (48.5%) > quercetin (47.1%) > 2''-O-GIV (40.5%) > apigenin (29.9%) and by the anthocyanins at the level of 0.1 micromol/mL was callistephin (45%) > keracyanin (33.2%) > pelargonidin (25.1%) > cyanidin (10.2%).

Animals↗

The role of EDTA in malonaldehyde formation from DNA oxidized by Fenton reagent systems.

Calf thymus DNA was oxidized by various Fenton reagent systems [Fe(II)/H(2)O(2)] with or without ethylenediamine tetraacetic acid (EDTA) under different reaction conditions. Calf DNA was also oxidized by a modified Fenton reagent (Fe(III)/H(2)O(2)/ascorbic acid) with EDTA. Malonaldehyde (MA) formed from DNA was derivatized into 1-methyl hydrazine, which was subsequently analyzed by gas chromatography with a nitrogen-phosphorus detector. MA formation increased linearly with an increase of Fe(II) concentration. MA formation reached a plateau at nearly 2 mmol/L of Fe(II) with 0.5 mmol/L of H(2)O(2). Addition of EDTA increased MA formation from DNA nearly 5 times. When DNA was oxidized with various amount of ethanol, MA formation decreased with an increase of ethanol concentration, either with or without EDTA. The rate of inhibition was greater without EDTA than with EDTA. When DNA was oxidized by a modified Fenton reagent, MA formation linearly increased with the increase of DNA. Ascorbic acid alone produced some MA upon oxidation.

Animals↗

Analysis of methoxyfenozide residues in fruits, vegetables, and mint by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Methoxyfenozide [3-methoxy-2-methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-dimethylethyl) hydrazide; RH-2485], in the formulation of INTREPID, was applied to various crops. Analysis of methoxyfenozide was accomplished by utilizing liquid-liquid extraction and partitioning, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validations for fruits, vegetables, and mint are reported. Methoxyfenozide mean recoveries ranged from 72 to 129% over three levels of fortification. The overall average of mean recoveries is 97 +/- 10%. The limit of quantitation for fruits, artichoke, cucumber, squash, and refined sugar was 0.010 ppm, with a detection limit of 0.005 ppm. For all other crops, the limit of quantitation was 0.050 ppm, with a detection limit of 0.025 ppm. No residues were found greater than the limit of quantitation in control samples. Residues above the limit of quantitation were found in all matrices except refined sugar. Foliage (bean, beet, pea, and radish) had greater residue levels of methoxyfenozide residue than their corresponding roots or pods. Other crop matrices contained <1.0 ppm of methoxyfenozide except artichoke, which had a mean of 1.10 ppm.

Chromatography, Liquid↗

Formation of dioxins from incineration of foods found in domestic garbage.

There has been great concern about the large amounts of garbage produced by domestic households in the modern world. One of the major sources of dioxins (PCDDs, PCDFs, and coplanar PCBs) in the environment is the combustion of domestic waste materials. Exhaust gases from an incinerator, in which mixtures of 67 food items--including fruits, vegetables, pasta, seafoods, meats, and processed foods and seasoned foods--were analyzed for dioxins. Gases collected at the chimney port (9.15 ng/g) contained less total dioxins than those collected at the chamber port (29.1 ng/g). The levels of Cl1-Cl6-PCDDs and Cl1-Cl5-PCDFs were much lower in the gas collected at the chimney port than in the gas collected at the chamber port. The levels of Cl7-Cl8-PCDDs and Cl6-Cl8-PCDFs were higher in the gas collected at the chimney port than in the gas collected at the chamber port. A total of Cl4-Cl8-PCDDs (1.84-3.04 ng/g) comprised over 80% of the total PCDDs formed (2.24-4.00 ng/g). Total PCDFs (16.2-22.6 ng/g) comprised 78-86% of the total dioxins formed (18.9-29.1 ng/g). The PCDFs formed in the greatest amounts were M1CDFs (9.68-10.7 ng/g). Mixtures of commonly consumed food items produced ppb levels of total dioxins in exhaust gases upon combustion, suggesting that incineration of domestic food wastes is one of the sources of dioxins in the environment. A mixture containing some seasoned foods, such as mayonnaise spread on bread, produced more dioxins (29.1 ng/g) than a mixture without seasoned foods did (18.9 ng/g).

Dioxins↗