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2.
Shokuhin Eiseigaku Zasshi ; 56(4): 166-72, 2015.
Artigo em Japonês | MEDLINE | ID: mdl-26346861

RESUMO

A headspace-GC analysis method for the determination of residual volatile substances (styrene, toluene, ethylbenzene, isopropylbenzene and propylbenzene) in food contact polystyrene (PS) was evaluated. Ten PS products were analyzed by this headspace-GC method and the Japanese official method, and the values obtained were almost equal. The performance of the method was evaluated, and the trueness, repeatability and reproducibility were 100.4-102.8%, 3.7-6.3% and 6.0-11.1%, respectively. The values of the performance parameters of the headspace-GC method fulfilled the requirements, and this method was confirmed to be extremely precise. Moreover, contamination of the GC equipment was minimized. The residual volatile substances in 58 PS products were surveyed with this method. All products met the specifications defined in the Japanese Food Sanitation Law, and no relationship was found between volatile substances and the sampling year or country of origin.


Assuntos
Cromatografia Gasosa/métodos , Utensílios de Alimentação e Culinária , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Poliestirenos/análise , Derivados de Benzeno/análise , Reprodutibilidade dos Testes , Tolueno/análise , Volatilização
3.
Shokuhin Eiseigaku Zasshi ; 55(6): 269-78, 2014.
Artigo em Japonês | MEDLINE | ID: mdl-25743590

RESUMO

Based on the Japanese Food Sanitation Law, the performances of official and alternative material test methods for cadmium (Cd) and lead (Pb) in food contact plastics were compared. Nineteen laboratories participated to an interlaboratory study, and quantified Cd and Pb in three PVC pellets. in the official method, a sample is digested with H2SO4, taken up in HCl, and evaporated to dryness on a water bath, then measured by atomic absorption spectrometry (AAS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). Statistical treatment revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 86-95%, 3.1-9.4% and 8.6-22.1%, respectively. The values of the performance parameters fulfilled the requirements , and the performances met the test specifications. The combination of evaporation to dryness on a hot plate and measurement by AAS or ICP-OES is applicable as an alternative method. However, the trueness and RSDr were inferior to those of the official method. The performance parameters obtained by using the microwave digestion method (MW method) to prepare test solution were better than those of the official method. Thus, the MW method is available as an alternative method. Induced coupled plasma-mass spectrometry (ICP-MS) is also available as an alternative method. However, it is necessary to ensure complete digestion of the sample.


Assuntos
Cádmio/análise , Utensílios de Alimentação e Culinária , Embalagem de Alimentos , Chumbo/análise , Espectrometria de Massas/métodos , Cloreto de Polivinila/análise , Cloreto de Polivinila/química , Espectrofotometria Atômica/métodos , Cádmio/isolamento & purificação , Chumbo/isolamento & purificação , Micro-Ondas
4.
Shokuhin Eiseigaku Zasshi ; 53(1): 52-6, 2012.
Artigo em Japonês | MEDLINE | ID: mdl-22450670

RESUMO

An improved analysis method for 2-mercaptoimidazoline in rubber products containing chlorine was developed. 2-Mercaptoimidazoline (20 µg/mL) is detected by means of TLC with two developing solvents in the official method. But, this method is not quantitative. Instead, we employed HPLC using water-methanol (9 : 1) as the mobile phase. This procedure decreased interfering peaks, and the quantitation limit was 2 µg/mL of standard solution. 2-Mercaptoimidazoline was confirmed by GC-MS (5 µg/mL) and LC/MS (1 µg/mL) in the scan mode. For preparation of test solution, a soaking extraction method, in which 20 mL of methanol was added to the sample and allowed to stand overnight at about 40°C, was used. This gave similar values to the Soxhlet extraction method (official method) and was more convenient. The results indicate that our procedure is suitable for analysis of 2-mercaptoimidazoline. When 2-mercaptoimidazoline is detected, it is confirmed by either GC/MS or LC/MS.


Assuntos
Cloro/análise , Etilenotioureia/análise , Borracha/análise , Cromatografia Líquida de Alta Pressão/métodos
5.
Echocardiography ; 28(8): 899-906, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21827536

RESUMO

BACKGROUND: Two-dimensional speckle tracking imaging (2DS) enables quantitative measurement of left ventricular strain. However, application of 2DS for measurement of circumferential carotid arterial strain (CAS) is not fully elucidated. We investigated the feasibility and reproducibility of measuring CAS by 2DS and determinants of CAS in healthy subjects. METHODS: Fifty-one healthy subjects (20 men and 31 women) with a mean age of 29 ± 11 years were enrolled. Ultrasound examination of bilateral common carotid arteries (CCAs) was performed and short axial views were recorded. The mean intima-media thickness (IMT) of bilateral CCAs was measured using semiautomated edge-detection software. Bilateral peak CAS at systole and time to peak CAS in each region were measured by 2DS. Stiffness parameter ß of bilateral CCAs was measured and bilateral cardio-ankle vascular index (CAVI) was recorded. Intraobserver and interobserver variabilities for mean CAS were calculated in 15 subjects. RESULTS: Of the 612 regions, 577 (94%) had adequate waveforms for measurement of CAS. The mean value of CAS was 6.7 ± 2.1%. Required time for CAS analysis was 128 ± 12 seconds per subject. Multiple regression analysis identified age (P < 0.001) and pulse pressure (P < 0.05) as independent significant determinants of mean CAS. Corrected CAS, which was calculated as mean CAS/pulse pressure, correlated with age, mean IMT, and stiffness parameter ß and systolic pressure (P < 0.001), age (P < 0.01), and stiffness parameter ß (P = 0.02) were identified as independent significant determinants of corrected CAS. Coefficient of variance (CV) of intraobserver and interobserver variabilities for mean CAS were 8.8% and 5.9%, respectively. CONCLUSIONS: 2DS in the CCAs is simply and quickly performed with high feasibility and excellent reproducibility. In healthy subjects, age and pulse pressure are the most important determinants of mean CAS.


Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Adulto , Índice Tornozelo-Braço , Artéria Carótida Primitiva/fisiologia , Espessura Intima-Media Carotídea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Ultrassonografia , Adulto Jovem
6.
J Biol Chem ; 282(27): 19273-81, 2007 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-17472962

RESUMO

3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (HRIs) are widely used to reduce serum cholesterol in patients with hypercholesterolemia. Previous studies have shown that HRIs can induce apoptosis in colon cancer cells. In this study, we investigated the mechanisms underlying the apoptosis-inducing effect of HRIs in greater detail. The HRI lovastatin induced apoptosis in the human colon cancer cell line SW480 by blocking the cholesterol synthesis pathway. Immunoblot analysis of antiapoptotic molecules, including survivin, XIAP, cIAP-1, cIAP-2, Bcl-2, and Bcl-X(L), revealed that only survivin expression was decreased by lovastatin. Survivin down-regulation by RNA interference induced apoptosis, and survivin overexpression rendered the cells resistant to lovastatin-induced growth inhibition. These results indicate that survivin down-regulation contributes substantially to the proapoptotic properties of lovastatin. Farnesyl pyrophosphate and geranylgeranyl pyrophosphate, two downstream intermediates in the cholesterol synthesis pathway, simultaneously reversed survivin down-regulation and the blocking of Ras isoprenylation by lovastatin. Ras isoprenylation is important for the activation of Ras-mediated signaling, including the activation of the phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway. The PI3-kinase inhibitor down-regulated survivin in SW480 cells. In addition, lovastatin blocked Ras activation and Akt phosphorylation. We conclude that survivin down-regulation is crucial in lovastatin-induced apoptosis in cancer cells and that lovastatin decreases survivin expression by inhibiting Ras-mediated PI3-kinase activation via the blocking of Ras isoprenylation.


Assuntos
Apoptose/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lovastatina/farmacologia , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/biossíntese , Linhagem Celular Tumoral , Colesterol/biossíntese , Colesterol/sangue , Neoplasias do Colo , Diterpenos/farmacologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hidroximetilglutaril-CoA-Redutases NADP-Dependentes/metabolismo , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Proteínas Inibidoras de Apoptose , Lovastatina/uso terapêutico , Proteínas de Neoplasias/biossíntese , Fosforilação/efeitos dos fármacos , Fosfatos de Poli-Isoprenil/farmacologia , Prenilação de Proteína/efeitos dos fármacos , Interferência de RNA/efeitos dos fármacos , Sesquiterpenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Survivina
7.
Shokuhin Eiseigaku Zasshi ; 46(4): 133-8, 2005 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-16180682

RESUMO

Migration from multi-layer laminated film pouches intended for retort foods was investigated through HPLC analysis with a fluorescence detector, and measurements of residue on evaporation, consumption of potassium permanganate and total organic carbon. HPLC analysis revealed that the levels of migrants in oil and the water which were heated in the pouches (121 degrees C, 30 min) were ten times of those in the corresponding official simulants under the official conditions; n-heptane (25 degrees C, 60 min), and water (95 degrees C, 30 min). Bisphenol A diglycidyl ether and related compounds were found in the oil and the water heated in the pouches, as well as in the simulants. These compounds were thought to have been present in the adhesive between the laminated films, and migrated through the food-contact film of the package. Consumption of potassium permanganate and residue on evaporation of the heated water were ten times of those of the water simulant, while the total organic carbon level of the heated water was several-hold greater than that of the water simulant. In addition, migrant levels per surface area of the pouch were one-fourth of the concentrations per content volume of the pouch. Since compliance with the legal limits is evaluated based on the concentration per surface area, real migration into foods would be underestimated by a factor of another four.


Assuntos
Compostos de Epóxi/análise , Análise de Alimentos/métodos , Embalagem de Alimentos , Conservação de Alimentos , Compostos Benzidrílicos , Cromatografia Líquida de Alta Pressão/métodos
8.
Shokuhin Eiseigaku Zasshi ; 45(1): 29-34, 2004 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-15168558

RESUMO

The effect of coexisting metals in a sample on the determination of lead and cadmium in plastics used for food contact materials was investigated. In the official method specified in the Japanese Food Sanitation Law, contents of lead and cadmium are determined by a dry incineration method using sulfuric acid. It was assumed that sometimes, coexisting metals in a sample may form insoluble sulfate and that lead sulfate might be adsorbed into the insoluble sulfate. Therefore, hydrochloric acid was added to the ash, to turn formed insoluble sulfate into soluble compounds (HCl addition method). We found that recoveries of cadmium were not affected in the presence of other metals except when calcium exceeded 20 mg/g in both methods. Recoveries of lead decreased in the presence of barium exceeding 0.1 mg/g or calcium exceeding 10 mg/g in the official method. However, improvement of recoveries was achieved with the HCl addition method and by reducing the sample amount to one-tenth (0.1 g) of that specified in the official method.


Assuntos
Cádmio/análise , Embalagem de Alimentos/legislação & jurisprudência , Chumbo/análise , Metais/análise , Plásticos/análise , Bário/análise , Cálcio/análise , Japão
9.
Shokuhin Eiseigaku Zasshi ; 44(1): 32-8, 2003 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-12749194

RESUMO

Migration from can-coatings into retorted canned food simulants (canned oil and water, 121 degrees C, 30 min) was investigated through HPLC with a fluorescence detector and evaporative light scattering detector, and by measurements of residue on evaporation and consumption of potassium permanganate. HPLC analysis revealed that migration into the canned oil was hundreds of times more than that into n-heptane (25 degrees C, 60 min, the official test conditions according to the Japanese Food Sanitation Law), whereas it was similar to the migration into isooctane-butyl acetate mixtures (60 degrees C, 60 min), and that migration into the canned water was several times more than that into water (95 degrees C, 30 min, the official test conditions). Residue on evaporation for the n-heptane extract was several-fold lower than 30 ppm (the official limit), whereas that for the isooctane-butyl acetate mixtures exceeded 30 ppm. Consumption of potassium permanganate for the canned water was 30 times higher than that for the water extract (95 degrees C, 30 min). The official test conditions for can-coatings, in particular the use of n-heptane as an oil simulant, were suggested to lead to substantial underestimation of migration into canned food.


Assuntos
Contaminação de Alimentos/análise , Embalagem de Alimentos , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Gasosa-Espectrometria de Massas
10.
Anticancer Res ; 22(6C): 3963-70, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12553019

RESUMO

BACKGROUND: To investigate the potential role of a nuclear transcription factor, early growth response-1 (Egr-1), in formation and progression of gastric cancer, we compared its expression in gastric cancers with that in non-cancerous tissues. MATERIALS AND METHODS: Egr-1 mRNA expression was measured using TaqMan RT-PCR. The corresponding protein expression was examined immunohistochemically. RESULTS: Egr-1 mRNA expression was significantly higher in gastric cancer tissues than in normal mucosa (p < 0.0005). These differences were also reflected by protein product expression. Moreover, Egr-1 mRNA expression was higher in cases with metastasis to lymph nodes or remote organs. In cultured gastric cancer cells known to have a high metastatic potential, expression of this mRNA was higher than that of parental cells. CONCLUSION: It was suggested that Egr-1 has a significant role in carcinogenesis and in cancer progression, especially metastasis. Measurement of this mRNA should be useful for evaluation of the metastatic potential of gastric cancer.


Assuntos
Proteínas de Ligação a DNA/biossíntese , Proteínas Imediatamente Precoces , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Fatores de Transcrição/biossíntese , Mama/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Colo/metabolismo , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Proteínas de Ligação a DNA/genética , Progressão da Doença , Proteína 1 de Resposta de Crescimento Precoce , Mucosa Gástrica/metabolismo , Humanos , Imuno-Histoquímica , Metástase Neoplásica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Células Tumorais Cultivadas
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