Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Nat Commun ; 14(1): 8239, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38086824

RESUMO

Electrons at the border of localization generate exotic states of matter across all classes of strongly correlated electron materials and many other quantum materials with emergent functionality. Heavy electron metals are a model example, in which magnetic interactions arise from the opposing limits of localized and itinerant electrons. This remarkable duality is intimately related to the emergence of a plethora of novel quantum matter states such as unconventional superconductivity, electronic-nematic states, hidden order and most recently topological states of matter such as topological Kondo insulators and Kondo semimetals and putative chiral superconductors. The outstanding challenge is that the archetypal Kondo lattice model that captures the underlying electronic dichotomy is notoriously difficult to solve for real materials. Here we show, using the prototypical strongly-correlated antiferromagnet CeIn3, that a multi-orbital periodic Anderson model embedded with input from ab initio bandstructure calculations can be reduced to a simple Kondo-Heisenberg model, which captures the magnetic interactions quantitatively. We validate this tractable Hamiltonian via high-resolution neutron spectroscopy that reproduces accurately the magnetic soft modes in CeIn3, which are believed to mediate unconventional superconductivity. Our study paves the way for a quantitative understanding of metallic quantum states such as unconventional superconductivity.

2.
J Reprod Immunol ; 148: 103369, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34492567

RESUMO

This study investigated if immunomodulatory treatment improves the in-vitro fertilization (IVF) success rates of women with two or more recurrent pregnancy losses (RPL) and repeated implantation failures (RIF) with cellular immune abnormalities and thrombophilia. We performed a retrospective cohort study of 197 RPL patients who received immunomodulatory and anticoagulation treatment undergoing IVF cycles (fresh or frozen embryo transfer). Patients were divided into four groups; Group 1: women with RPL but without RIF, Group 2: women with RPL and RIF (≥3), Group 3: women with RPL after IVF cycles (>2) and without RIF, and Group 4: women with RPL after IVF cycles and RIF. Patients received immunomodulatory treatment with prednisone-only or prednisone and intravenous immunoglobulin G (IVIG) and anticoagulation treatment with low molecular weight heparin and low dose aspirin. IVF success rates of study groups were compared to those of the historical controls. The pregnancy rate of IVF cycles with immunomodulatory treatment was significantly increased in all patients (48.2 % vs. 33.0 %, P < 0.001), Group 1 (54.2 % vs. 30.5 %, P < 0.005) and Group 2 (33.3 % vs. 11.0 %, P < 0.005) as compared to historical controls. The live birth rates per ET cycle were significantly improved for all patients (1.8 % vs. 39.6 %, P < 0.001), and study groups compared to their historical controls (Group 1, 43.1 % vs. 0 %; Group 2, 33.3 % vs. 2.5 %; Group 3, 45.5 % vs. 2.3 %; and Group 4, 16.7 % vs. 1.2 %, P < 0.001, respectively). Immunomodulatory and anticoagulation treatment significantly improved the reproductive outcomes of IVF cycles in women with a history of RPL and/or RIF of immune etiologies.


Assuntos
Aborto Habitual/tratamento farmacológico , Anti-Inflamatórios/uso terapêutico , Anticoagulantes/uso terapêutico , Aspirina/uso terapêutico , Heparina de Baixo Peso Molecular/uso terapêutico , Imunoglobulinas Intravenosas/uso terapêutico , Prednisona/uso terapêutico , Trombofilia/tratamento farmacológico , Adolescente , Adulto , Feminino , Fertilização in vitro , Humanos , Imunização , Gravidez , Resultado da Gravidez , Falha de Tratamento , Adulto Jovem
3.
J Reprod Immunol ; 118: 70-75, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27716543

RESUMO

Alterations in normal balance of B cell subsets have been reported in various rheumatic diseases. In this study, we report a woman with a history of recurrent pregnancy losses (RPL) and infertility who had low levels of memory B cells. A 35-year-old woman with a history of RPL and infertility was demonstrated to have increased peripheral blood CD19+ B cells with persistently low levels of memory B cell subsets. Prior to the frozen donor egg transfer cycle, prednisone and intravenous immunoglobulin G (IVIg) treatment was initiated and patient achieved dichorionic diamniotic twin pregnancies. During pregnancy, proportion (%) of switched memory B cells CD27+IgD- increased, while percent of total CD19+ B cells and CD27-IgD+ naive B cells were gradually decreased with a high dose IVIg treatment. She developed cervical incompetence at 20 weeks of gestation, received a Cesarean section at 32 weeks of gestation due to preterm labor, and delivered twin babies. B cell subset abnormalities may be associated with infertility, RPL and preterm labor, and further investigation is needed.


Assuntos
Aborto Habitual/imunologia , Subpopulações de Linfócitos B/imunologia , Linfócitos B/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Infertilidade Feminina/imunologia , Trabalho de Parto Prematuro/imunologia , Prednisona/uso terapêutico , Aborto Habitual/terapia , Adulto , Antígenos CD19/metabolismo , Feminino , Humanos , Switching de Imunoglobulina , Memória Imunológica , Infertilidade Feminina/terapia , Gravidez/imunologia
4.
Phys Rev Lett ; 117(10): 107001, 2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27636488

RESUMO

We have studied the magnetic excitations of electron-doped Sr_{2-x}La_{x}IrO_{4} (0≤x≤0.10) using resonant inelastic x-ray scattering at the Ir L_{3} edge. The long-range magnetic order is rapidly lost with increasing x, but two-dimensional short-range order (SRO) and dispersive magnon excitations with nearly undiminished spectral weight persist well into the metallic part of the phase diagram. The magnons in the SRO phase are heavily damped and exhibit anisotropic softening. Their dispersions are well described by a pseudospin-1/2 Heisenberg model with exchange interactions whose spatial range increases with doping. We also find a doping-independent high-energy magnetic continuum, which is not described by this model. The spin-orbit excitons arising from the pseudospin-3/2 manifold of the Ir ions broaden substantially in the SRO phase, but remain largely separated from the low-energy magnons. Pseudospin-1/2 models are therefore a good starting point for the theoretical description of the low-energy magnetic dynamics of doped iridates.

5.
Phys Rev Lett ; 116(13): 136401, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27081993

RESUMO

We have used Raman scattering to investigate the magnetic excitations and lattice dynamics in the prototypical spin-orbit Mott insulators Sr_{2}IrO_{4} and Sr_{3}Ir_{2}O_{7}. Both compounds exhibit pronounced two-magnon Raman scattering features with different energies, line shapes, and temperature dependencies, which in part reflect the different influence of long-range frustrating exchange interactions. Additionally, we find strong Fano asymmetries in the line shapes of low-energy phonon modes in both compounds, which disappear upon cooling below the antiferromagnetic ordering temperatures. These unusual phonon anomalies indicate that the spin-orbit coupling in Mott-insulating iridates is not sufficiently strong to quench the orbital dynamics in the paramagnetic state.

6.
Sci Rep ; 5: 13366, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26300075

RESUMO

Spin-wave (magnon) scattering, when clearly observed by Raman spectroscopy, can be simple and powerful for studying magnetic phase transitions. In this paper, we present how to observe magnon scattering clearly by Raman spectroscopy, then apply the Raman method to study spin-ordering and spin-reorientation transitions of hexagonal manganite single crystal and thin films and compare directly with the results of magnetization measurements. Our results show that by choosing strong resonance condition and appropriate polarization configuration, magnon scattering can be clearly observed, and the temperature dependence of magnon scattering can be simple and powerful quantity for investigating spin-ordering as well as spin-reorientation transitions. Especially, the Raman method would be very helpful for investigating the weak spin-reorientation transitions by selectively probing the magnons in the Mn(3+) sublattices, while leaving out the strong effects of paramagnetic moments of the rare earth ions.

7.
Acta Physiol (Oxf) ; 205(1): 61-70, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22353229

RESUMO

AIM: It is known that garlic has antioxidative and anti-inflammatory properties. Aged red garlic (ARG), a novel aged garlic formulation, has higher antioxidant effects than fresh raw garlic. This study was performed to examine the anti-inflammatory effects of ARG extract (ARGE). METHODS: The anti-inflammatory effects of ARGE were evaluated in the lipopolysaccharide (LPS)-treated Raw 264.7 macrophages and acute lung inflammatory mice. NO production was determined by the Griess method, and iNOS, HO-1 and COX-2 expressions were measured using Western blot analysis. Histology and inflammation extent of lung were analysed using haematoxylin-eosin staining and immunohistochemistry. RESULTS: ARGE treatment markedly reduced LPS-induced nitrite production in RAW 264.7 macrophages and reduced inducible nitric oxide synthase (iNOS) expression. Treatment of cells with ARGE led to a significant increase in haeme oxygenase-1 (HO-1) protein expression, which was mediated by stimulating the expression of nuclear factor erythroid 2-related factor 2 (Nrf2). Treatment with zinc protoporphyrin, a selective inhibitor of HO-1, significantly reversed the ARGE-mediated inhibition of nitrite production (P < 0.05). In LPS-induced inflammatory mice, ARGE treatment down-regulated iNOS and COX-2 expressions, while it up-regulated HO-1 expression. CONCLUSION: These results show that ARGE reduces LPS-induced nitric oxide production in RAW 264.7 macrophages through HO-1 induction and suggest that ARGE may have potential effects on prevention and treatment of acute inflammatory lung injury.


Assuntos
Anti-Inflamatórios/farmacologia , Alho , Heme Oxigenase-1/metabolismo , Pulmão/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Óxido Nítrico/biossíntese , Extratos Vegetais/farmacologia , Pneumonia/tratamento farmacológico , Animais , Anti-Inflamatórios/uso terapêutico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Lipopolissacarídeos/farmacologia , Pulmão/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Extratos Vegetais/uso terapêutico , Pneumonia/metabolismo , Protoporfirinas/farmacologia
8.
Cancer Treat Rev ; 37(2): 89-96, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20667660

RESUMO

Although surgery provides excellent control for localized prostate cancer, pathologic examination of more than one-third of specimens will reveal positive surgical margins, seminal vesicle invasion, and/or extracapsular extension, thus putting these patients at increased risk of cancer recurrence. "Adjuvant" radiotherapy (ART) refers to treatment of patients with an undetectable PSA that is delivered after surgery (usually less than 12-16 weeks from the time of surgery). Currently, there are no standardized guidelines for the use of ART and the bulk of patients are solely monitored for signs of recurrence after prostatectomy. In this article, we review the evidence for ART from three randomized clinical trials. Although radiation therapy in the adjuvant setting has generally been well tolerated, we also examine the complication data associated with treatment. In addition, we discuss the technical aspects of treatment, including dose escalation and treatment target volume. The ability to increase dose and limit target volume would likely result in higher cure rates and decreased side effects, thus ensuring a better clinical outcome and increasing quality of life. Finally, we discuss the cost-effectiveness of ART, in the context of other medical interventions.


Assuntos
Prostatectomia , Neoplasias da Próstata/radioterapia , Análise Custo-Benefício , Humanos , Masculino , Neoplasias da Próstata/cirurgia , Dosagem Radioterapêutica , Radioterapia Adjuvante/efeitos adversos , Radioterapia Adjuvante/economia , Radioterapia Adjuvante/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Terapia de Salvação
10.
Int J Tuberc Lung Dis ; 13(5): 594-600, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19383192

RESUMO

SETTING: A tuberculosis (TB) referral hospital in South Korea. OBJECTIVE: To evaluate predictors of treatment outcomes and survival among non-human immunodeficiency virus (HIV) infected patients with extensively drug-resistant TB (XDR-TB). DESIGN: Patients who were diagnosed with XDR-TB at the National Masan Tuberculosis Hospital from January 2001 to December 2005 were included in this study. We conducted a retrospective review of their medical records and mortality data. RESULTS: A total of 176 non-HIV-infected patients with XDR-TB were included. TB-related mortality was 48% (84/176), and the median survival time from the diagnosis date of XDR-TB was 51 months (range 0-127, 95%CI 32.53-69.47). Cure and treatment completion were classified as favourable outcome and treatment failure, death during treatment and default as poor outcome. Previous TB treatment with second-line drugs (aOR 2.76, 95%CI 1.02-7.44) and cavitary disease (aOR 3.01, 95%CI 1.12-8.08) were independent risk factors for poor outcome. Use of linezolid (aOR 0.10, 95%CI 0.01-0.69) and surgical resection (aOR 0.18, 95%CI 0.04-0.78) were associated with favourable outcome. CONCLUSION: There was high mortality in non-HIV-infected patients with XDR-TB at a TB referral hospital in South Korea. Adjunctive surgical treatment and linezolid improved the outcome for selected patients with XDR-TB.


Assuntos
Antituberculosos/uso terapêutico , Tuberculose Extensivamente Resistente a Medicamentos/mortalidade , Pneumonectomia/métodos , Adulto , Tuberculose Extensivamente Resistente a Medicamentos/terapia , Feminino , Seguimentos , Infecções por HIV , Hospitais Especializados/estatística & dados numéricos , Humanos , Coreia (Geográfico)/epidemiologia , Masculino , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento
11.
J Gastroenterol Hepatol ; 24(4): 658-66, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19175827

RESUMO

BACKGROUND AND AIM: Gastric cancers present with distinctive carcinogenesis pathways that vary with the mucin phenotypes. We attempted to elucidate the relations between the characteristics of the mucin phenotypes of gastric cancer and the tumor invasiveness. METHODS: Gastric adenocarcinomas that were resected surgically between August 2005 and April 2007 were included in the present study. The gastric cancers were subclassified into gastric and intestinal mucin phenotypes if more than 10% of cancer cells exhibited gastric (MUC5AC and/or MUC6) and intestinal (MUC2 or CD10) markers, respectively. RESULTS: The mucin phenotypes of 123 gastric cancers were gastric (n = 31), intestinal (n = 43), mixed (n = 28) and unclassified (n = 21). The mucin phenotype was related to histological type (P < 0.001), Lauren's classification (P = 0.001) and size (P = 0.014) of the gastric adenocarcinoma, but not to its location or to the presence of Helicobacter pylori infection. The unclassified mucin phenotype exhibited the largest number of lymph node metastases (P = 0.007), lymphatic invasions (P < 0.001) and neural invasions (P = 0.026), whereas the intestinal mucin phenotype exhibited the lowest invasiveness. CONCLUSION: The mucin phenotype reflects the biological behavior of gastric cancer, with the intestinal and unclassified mucin phenotypes exhibiting the lowest and highest invasiveness, respectively.


Assuntos
Adenocarcinoma/química , Mucinas/análise , Neoplasias Gástricas/química , Adenocarcinoma/genética , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Adulto , Idoso , Diferenciação Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Helicobacter pylori/isolamento & purificação , Humanos , Imuno-Histoquímica , Metástase Linfática , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mucina-5AC/análise , Mucina-2/análise , Mucina-6/análise , Invasividade Neoplásica , Neprilisina/análise , Fenótipo , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
12.
J Appl Microbiol ; 104(3): 692-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17927749

RESUMO

AIMS: To isolate and identify antioomycete substances from Fusarium oxysporum EF119 against Phytophthora infestans and to investigate their antimicrobial activities against various plant pathogenic bacteria, oomycetes and true fungi. METHODS AND RESULTS: Two antioomycete substances were isolated from liquid cultures of F. oxysporum EF119, which shows a potent disease control efficacy against tomato late blight caused by P. infestans. They were identified as bikaverin and fusaric acid by mass and nuclear magnetic resonance spectral analyses. They inhibited the mycelial growth of plant pathogenic oomycetes and fungi. Fusaric acid also effectively suppressed the cell growth of various plant pathogenic bacteria, but bikaverin was virtually inactive. Treatment with bikaverin at 300 microg ml(-1) suppressed the development of tomato late blight by 71%. Fusaric acid provided effective control against tomato late blight and wheat leaf rust over 67% at concentrations more than 100 microg ml(-1). CONCLUSIONS: Both bikaverin and fusaric acid showed in vitro and in vivo antioomycete activity against P. infestans. SIGNIFICANCE AND IMPACT OF THE STUDY: Fusarium oxysporum EF119 producing both bikaverin and fusaric acid may be used as a biocontrol agent against tomato late blight caused by P. infestans.


Assuntos
Microbiologia de Alimentos , Fungicidas Industriais/farmacologia , Ácido Fusárico/farmacologia , Fusarium/química , Phytophthora/efeitos dos fármacos , Xantonas/farmacologia , Capsicum/microbiologia , Ácido Fusárico/química , Extratos Vegetais/farmacologia , Xantonas/química
13.
Artigo em Inglês | MEDLINE | ID: mdl-18051126

RESUMO

Significant research has been conducted in radiation beam gating technology to manage target and organ motions in radiotherapy treatment of cancer patients. As more and more on-board imagers are installed onto linear accelerators, fluoroscopic imaging becomes readily available at the radiation treatment stage. Thus, beam gating parameters, such as beam-on timing and beam-on window can be potentially determined by employing image registration between treatment planning CT images and fluoroscopic images. We propose a new registration method on deformable soft tissue between fluoroscopic images and DRR (Digitally Reconstructed Radiograph) images from planning CT images using active shape models. We present very promising results of our method applied to 30 clinical datasets. These preliminary results show that the method is very robust for the registration of deformable soft tissue. The proposed method can be used to determine beam-on timing and treatment window for radiation beam gating technology, and can potentially greatly improve radiation treatment quality.


Assuntos
Fluoroscopia/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Técnica de Subtração , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Inteligência Artificial , Humanos , Imageamento Tridimensional/métodos , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radioterapia Assistida por Computador/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Br J Cancer ; 97(5): 700-4, 2007 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-17637680

RESUMO

We investigated the risk of gastric cancer by subsite in relation to cigarette smoking and alcohol in a large population-based cohort of 669 570 Korean men in an insurance plan followed for an average 6.5 years, yielding 3452 new cases of gastric cancer, of which 127 were cardia and upper-third gastric cancer, 2409 were distal gastric cancer and 1007 were unclassified. A moderate association was found between smoking, cardia and upper-third (adjusted relative risk (aRR) 2.2; 95% confidence interval (CI) 1.4-3.5) and distal cancers (aRR=1.4; 95% CI=1.3-1.6). We also found a positive association between alcohol consumption and distal (aRR=1.3; 95% CI=1.2-1.5) and total (aRR=1.2; 95% CI=1.1-1.4) gastric cancer. Combined exposure to high levels of tobacco and alcohol increased the risk estimates further; cardia and upper-third gastric cancers were more strongly related to smoking status than distal gastric cancer.British Journal of Cancer (2007) 97, 700-704. doi:10.1038/sj.bjc.6603893 www.bjcancer.com Published online 17 July 2007.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Fumar/efeitos adversos , Neoplasias Gástricas/etiologia , Adulto , Povo Asiático/estatística & dados numéricos , Estudos de Coortes , Humanos , Seguro Saúde/estatística & dados numéricos , Coreia (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Neoplasias Gástricas/etnologia
15.
Lett Appl Microbiol ; 44(3): 332-7, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17309513

RESUMO

AIMS: To isolate endophytic fungi from vegetable plants and examine their in vivo anti-oomycete activity against Phytophthora infestans in tomato plants. METHODS AND RESULTS: Endophytic fungi were isolated from surface-sterilized plant tissues and anti-oomycete activity was measured by in vivo assay using tomato seedlings. Endophytic fungi showing potent anti-oomycete activity were identified by morphological characteristics and nuclear ribosomal ITS1-5.8S-ITS2 sequence analysis. A total of 152 isolates were obtained from 66 healthy tissue samples of cucumber, red pepper, tomato, pumpkin and Chinese cabbage and the fermentation broths of 23 isolates showed potent in vivo anti-oomycete activity against tomato late blight with control values over 90%. The Fusarium oxysporum strain EF119, which was isolated from roots of red pepper, showed the most potent disease control efficacy against tomato late blight. In dual-culture tests, it inhibited the growth of Pythium ultimum, P. infestans and Phytophthora capsici. CONCLUSIONS: Among endophytic fungi isolated from healthy tissues of vegetable plants, F. oxysporum EF119 showed the most potent in vivo anti-oomycete activity against tomato late blight and in vitro anti-oomycete activity against several oomycete pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Endophytic fungi showing anti-oomycete activity in vitro and in vivo may be used as biocontrol agents particularly of tomato late blight.


Assuntos
Produtos Agrícolas/microbiologia , Fungos/fisiologia , Oomicetos/fisiologia , Doenças das Plantas/microbiologia , Solanum lycopersicum/microbiologia , Verduras/microbiologia , Fungos/química , Fungos/isolamento & purificação , Controle Biológico de Vetores , Raízes de Plantas/microbiologia
16.
Food Addit Contam ; 22(11): 1083-6, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16332630

RESUMO

Volatile N-nitrosamine (VNA) levels in South Korean and imported alcoholic beverages were determined between 1995 and 2002. A total of 147 alcoholic beverages, including lager beer, whiskey, liqueurs and traditional Korean alcoholic beverages (Chungju, Takju and Soju), were analysed for their VNA content by GC-TEA. Of eight VNAs (N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosomorphorine (NMOR), N-nitrosodibuthylamine (NDBA), N-nitrosopiperidine (NPIP), N-nitrosodiprophylamine (NDPA) and N-nitrosodiphenylamine (NDPhA)) only NDMA was detected. In 1995, NDMA was detected in 79.3% of domestic beers; the average was 0.8 microg kg-1. Seven years later, the average NDMA level for 18 domestic beers was 0.3 microg kg-1 and it was positive in 55.6% samples. In whisky and liqueurs, NDMA levels averaged <0.1 microg kg-1 in both 1995 and 2002. Average NDMA levels of Chungju in 1995 were <0.1 microg kg-1, but NDMA was not detected in 2002. Takju had undetectable levels of NDMA both times. In 1995, NDMA was found in four of six Soju samples, but in 2002, NDMA could not be detected.


Assuntos
Bebidas Alcoólicas/análise , Dimetilnitrosamina/análise , Contaminação de Alimentos/análise , Cerveja/análise , Carcinógenos/análise , Análise de Alimentos/métodos , Humanos , Coreia (Geográfico)
17.
Int J Mol Med ; 13(1): 81-6, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14654975

RESUMO

Silibinin, the flavonoid found in the milk thistle, has been shown to suppress cell growth and exhibit anti-cancer effects. Some flavonoids were reported to inhibit angiogenesis which is essential for tumor growth and metastasis. In this study, to clarify the underlying mechanisms for the anti-cancer effect of silibinin, we examined the effects of silibinin on human endothelial ECV304 cells. Silibinin was found to suppress the growth and induce the apoptosis of ECV304 cells. The induction of apoptosis by silibinin was confirmed by ladder-patterned DNA fragmentation, cleaved and condensed nuclear chromatin and DNA hypoploidy. Silibinin could effectively inhibit constitutive NF-kappaB activation as revealed by electrophoretic mobility shift assay and NF-kappaB-dependent luciferase reporter study. Consistent with this, silibinin treatment resulted in a significant decrease in the nuclear level of p65 subunit of NF-kappaB. In addition, silibinin treatment caused a change in the ratio of Bax/Bcl-2 in a manner that favors apoptosis. Silibinin also induced the cytochrome c release, activation of caspase-3 and caspase-9 and cleavage of PARP. These results suggest that silibinin may exert, at least partly, its anti-cancer effect by inhibiting angiogenesis through induction of endothelial apoptosis via modulation of NF-kappaB, Bcl-2 family and caspases.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Células Endoteliais/fisiologia , NF-kappa B/metabolismo , Silimarina/metabolismo , Citocromos c/metabolismo , DNA/metabolismo , Humanos , NF-kappa B/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Silibina , Proteína X Associada a bcl-2
18.
Food Addit Contam ; 20(1): 31-6, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12519716

RESUMO

Only N-nitrosodimethylamine (NDMA) was detected when N-nitrosamines (NA) were analysed in seven dried seafood products, either uncooked or cooked. The cooking methods used were a briquet fire, a gas range, an electric oven, a microwave oven, a steam cooker and an electric coil cooker. The contents of NDMA ranged from 1.0 to 46.9 microgram kg(-1) in uncooked products. When these samples were cooked, regardless of the cooking method, the content of NDMA tended to increase, ranging from 1.1 to 630.5 microgram kg(-1). In general, indirect heating such as a steam cooker and a microwave oven, as compared with direct heating such as a gas range and a briquet fire, caused less increase in NDMA during cooking.


Assuntos
Dimetilnitrosamina/análise , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Temperatura Alta , Alimentos Marinhos/análise , Animais , Crustáceos/química , Peixes , Coreia (Geográfico) , Moluscos/química , Nitrosaminas/análise
19.
Food Chem Toxicol ; 40(7): 949-57, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12065217

RESUMO

The formation of carcinogenic nitrosamines under simulated gastric conditions was studied during the incubation of amine rich food and nitrate, and its possible inhibition by adding kumquat, sweet orange, strawberry, garlic, kale juices, Maesil (Prunus mume) and green tea extracts. The strawberry, kale juices, Maesil and green tea extracts were equally effective in reducing the formation of N-nitrosodimethylamine (NDMA). The fruits of P. mume SIEB. et ZACC. (Korean name, Maesil) have been used as a traditional drug and health food in Korea. During four weeks of test (designated EW1, EW2, EW3 and EW4; experiment week 1, 2, 3 and 4 diets) volunteers consumed a diet of low nitrate and amine (EW1) and consumed a fish meal rich in amines as nitrosatable precursors in combination with intake of nitrate-containing drinking water without (EW2) or with Maesil and green tea extracts (EW3 and EW4, respectively). The intake of nitrate-containing drinking water (340 mg nitrate/100 ml) resulted in a significant rise in mean salivary nitrate and nitrite concentrations and in mean urinary nitrate levels. Mean urinary nitrate was increased to 455.0+/-66.2, 334.6+/-67.8 and 333.4+/-50.7 mg/18 h after the nitrate intake of EW2, EW3 and EW4, respectively. Significant increases in urinary dimethylamine and trimethylamine levels were observed in consumption of diets (EW2, EW3, and EW4) rich in amine and nitrate. Maesil and green tea extract in EW3 and EW4 enhanced the increase of urinary dimethylamine and trimethylamine levels. Urinary excretion of N-nitrosodimethylamine in consumption of diet rich in nitrate and amine (EW2) increased to 6504.4+/-2638.7 ng/18 h from 257.0+/-112.0 ng/18 h of low nitrate and amine diet (EW1). Korean green tea and Maesil extracts in nitrate and amine rich diet reduced the excretion of N-nitrosodimethylamine to 249.7+/-90.6 and 752.7+/-595.3 ng/18 h, respectively, compared with 6504.4+/-2638.7 ng /18 h after ingestion of TD1 diet.


Assuntos
Aminas/administração & dosagem , Dieta , Nitratos/administração & dosagem , Nitrosaminas/antagonistas & inibidores , Extratos Vegetais/farmacologia , Prunus/química , Chá/química , Adulto , Anticarcinógenos/farmacologia , Feminino , Humanos , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA