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1.
Phys Rev Lett ; 100(22): 221803, 2008 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-18643415

RESUMO

The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.

2.
Genes Immun ; 9(4): 302-8, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18418398

RESUMO

T-box transcription factor, T-bet, has a central role in the differentiation of T-helper (Th) progenitor cells to Th1 or Th2 effector cells, partly by regulating the expression of genes such as interferon-gamma (IFN-gamma). However, the direct target genes, especially those mediating the transcriptional network initiated by T-bet, are not yet fully understood. By combining chromatin immunoprecipitation from Th1 cells with human cytosine-phosphate-guanine-island array analysis, Onecut 2 (OC2), which encodes a member of the ONECUT class of transcriptional activators, was identified as a direct target gene of T-bet. OC2 is expressed in Th1 but not Th2 cells and reporter assays showed that T-bet transactivates OC2 transcription through putative T-bet half-sites locating -451 to -347 of OC2 promoter region. Moreover, we found that OC2 binds and transactivates human T-bet promoter. These results suggest that not only cell-extrinsic regulation via the IFN-gamma/STAT1 pathway, but also cell-intrinsic transcriptional positive feedback loop between T-bet and OC2 could be involved in Th1 development.


Assuntos
Proteínas de Homeodomínio/genética , Proteínas com Domínio T/genética , Células Th1/imunologia , Fatores de Transcrição/genética , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Chlorocebus aethiops , Imunoprecipitação da Cromatina , Sequência Consenso , Ilhas de CpG/genética , Genes Reporter , Hemaglutininas/metabolismo , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/metabolismo , Humanos , Luciferases de Renilla/metabolismo , Dados de Sequência Molecular , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas com Domínio T/metabolismo , Células Th1/metabolismo , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Ativação Transcricional
3.
Phys Rev Lett ; 96(10): 101802, 2006 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-16605724

RESUMO

The Kamioka Liquid scintillator Anti-Neutrino Detector is used in a search for single neutron or two-neutron intranuclear disappearance that would produce holes in the -shell energy level of (12)C nuclei. Such holes could be created as a result of nucleon decay into invisible modes (inv), e.g., n--> 3v or nn--> 2v. The deexcitation of the corresponding daughter nucleus results in a sequence of space and time-correlated events observable in the liquid scintillator detector. We report on new limits for one- and two-neutron disappearance: tau(n--> inv) > 5.8 x 10(29) years and tau (nn--> inv) > 1.4 x 10(30) years at 90% C.L. These results represent an improvement of factors of approximately 3 and >10(4) and over previous experiments.

4.
Clin Exp Immunol ; 144(1): 85-93, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16542369

RESUMO

Chromosome 22q11.2 deletion syndrome is a common disorder characterized by thymic hypoplasia, conotruncal cardiac defect and hypoparathyroidism. Patients have a risk of infections and autoimmunity associated with T lymphocytopenia. To assess the immunological constitution of patients, the numerical changes and cytokine profile of circulating T cells were analysed by flow cytometry and real-time polymerase chain reaction (PCR). CD3+, CD4+, T cell receptor (TCR)alphabeta+ or CD8alphaalpha+ cell counts were lower, and CD56+ cell counts were higher in patients than in controls during the period from birth to adulthood. The ageing decline of CD3+ or CD4+ cell counts was slower in patients than in controls. The proportion of CD8alphaalpha+ cells increased in controls, and the slope index was larger than in patients. On the other hand, both the number and proportion of Valpha24+ cells increased in patients, and the slope indexes tended to be larger than in controls. The positive correlation of the number of T cells with CD8alphaalpha+ cells was observed only in patients, and that with Valpha24+ cells was seen only in controls. No gene expression levels of interferon (IFN)-gamma, interleukin (IL)-10, transforming growth factor (TGF)-beta, cytotoxic T lymphocyte antigen 4 (CTLA4) or forkhead box p3 (Foxp3) in T cells differed between patients and controls. There was no significant association between the lymphocyte subsets or gene expression levels and clinical phenotype including the types of cardiac disease, hypocalcaemia and frequency of infection. These results indicated that T-lymphocytopenia in 22q11.2 deletion patients became less severe with age under the altered composition of minor subsets. The balanced cytokine profile in the limited T cell pool may represent a T cell homeostasis in thymic deficiency syndrome.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 22/genética , Citocinas/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Envelhecimento/genética , Envelhecimento/imunologia , Antígenos CD , Antígenos de Diferenciação/análise , Complexo CD3/imunologia , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos/imunologia , Antígeno CTLA-4 , Criança , Pré-Escolar , Cromossomos Humanos Par 22/imunologia , Síndrome de DiGeorge/genética , Síndrome de DiGeorge/imunologia , Feminino , Fatores de Transcrição Forkhead/análise , Expressão Gênica/genética , Expressão Gênica/imunologia , Humanos , Lactente , Interferon gama/análise , Interleucina-10/análise , Contagem de Linfócitos , Masculino , RNA Mensageiro/análise , Receptores de Antígenos de Linfócitos T/imunologia , Fator de Crescimento Transformador beta/análise
5.
Nature ; 436(7050): 499-503, 2005 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16049478

RESUMO

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

6.
Phys Rev Lett ; 94(8): 081801, 2005 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-15783875

RESUMO

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.

7.
J Med Genet ; 41(10): 763-7, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15466010

RESUMO

BACKGROUND: Familial haemophagocytic lymphohistiocytosis (FHL) has an autosomal recessive mode of inheritance and consists of at least three subtypes. FHL2 subtype with perforin (PRF1) mutation accounts for 30% of all FHL cases, while FHL with MUNC13-4 mutation was recently identified and designated as FHL3 subtype. OBJECTIVE: To examine MUNC13-4 mutations and the cytotoxic function of MUNC13-4 deficient T lymphocytes in Japanese FHL patients METHODS: Mutations of MUNC13-4 and the cytotoxicity of MUNC13-4-deficient cytotoxic T lymphocytes (CTL) were analysed in 16 Japanese families with non-FHL2 subtype. RESULTS: Five new mutations of the MUNC13-4 gene were identified in six families. The mutations were in the introns 4, 9, and 18, and exons 8 and 19. Two families had homozygous mutations, while the remaining four had compound heterozygous mutations. Cytotoxicity of MUNC13-4 deficient CTL was low compared with control CTL, but was still present. Clinically, the onset of disease tended to occur late; moreover, natural killer cell activity was not deficient in some FHL3 patients. CONCLUSIONS: MUNC13-4 mutations play a role in the development of FHL3 through a defective cytotoxic pathway.


Assuntos
Histiocitose de Células não Langerhans/genética , Mutação/genética , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Idade de Início , Análise Mutacional de DNA , Éxons/genética , Feminino , Histiocitose de Células não Langerhans/imunologia , Histiocitose de Células não Langerhans/fisiopatologia , Humanos , Lactente , Íntrons/genética , Japão , Masculino , Dados de Sequência Molecular , Linhagem
9.
Pediatr Cardiol ; 24(5): 507-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14627326

RESUMO

A 5-year-old girl with isolated congenital left pulmonary artery agenesis suffered from recurrent attacks of dyspnea and right-sided pneumonia due to the stenosis of the right main bronchus. The division of ligamentum of the ductus arteriosus and suspension of the right pulmonary artery resulted in the disappearance of symptoms. It is notable that the compression of contralateral bronchus by the remaining pulmonary artery can cause respiratory symptoms in patients with isolated unilateral pulmonary artery agenesis.


Assuntos
Asma/etiologia , Broncopatias/etiologia , Artéria Pulmonar/anormalidades , Broncopatias/patologia , Pré-Escolar , Constrição Patológica , Humanos , Masculino
10.
Phys Rev Lett ; 90(2): 021802, 2003 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-12570536

RESUMO

KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded.

11.
Neuroscience ; 113(1): 37-45, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12123682

RESUMO

The main mammalian circadian pacemaker is located in the suprachiasmatic nucleus of the hypothalamus. Clock genes such as the mouse Period gene (mPer) play a role in this core clock mechanism in the mouse. With brief light exposure during the subjective night, the photic information, which is conveyed directly to the suprachiasmatic nucleus via the retinohypothalamic tract, results in mPer1 and mPer2 expression in the suprachiasmatic nucleus. Glutamate and pituitary adenylate cyclase-activating polypeptide (PACAP) are co-stored in the retinohypothalamic tract. Recent studies have suggested that not only glutamate but also PACAP are key players in the phase shift that occurs during subject night; however, research demonstrating a direct association between the PACAP-induced phase shift and mPer gene expression has yet to be conducted. In the present study, PACAP (200 pmol) injected into the lateral ventricle during subjective night (circadian time 16; circadian time 12, onset of locomotor activity) caused a moderate phase delay associated with moderate expression of mPer1 and only slight expression of mPer2 in the mouse suprachiasmatic nucleus. PACAP-induced mPer1 expression was also observed in the paraventricular nucleus and periventricular area of the hypothalamus. (+)MK-801 (0.5 mg/kg), an N-methyl-D-aspartate (NMDA) receptor antagonist, suppressed both the PACAP-induced phase delay and mPer1 expression. From these results we suggest that PACAP induces phase delays in the mouse circadian rhythm in association with an increase of mPer expression in the suprachiasmatic nucleus via the activation of NMDA receptors.


Assuntos
Ritmo Circadiano/efeitos dos fármacos , Neuropeptídeos/farmacologia , Neurotransmissores/farmacologia , Proteínas Nucleares/metabolismo , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Núcleo Supraquiasmático/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Proteínas de Ciclo Celular , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Hibridização In Situ , Injeções Intraventriculares , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Nucleares/efeitos dos fármacos , Proteínas Circadianas Period , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Receptores de N-Metil-D-Aspartato/metabolismo , Núcleo Supraquiasmático/metabolismo , Fatores de Transcrição
12.
Pharmacol Biochem Behav ; 70(2-3): 375-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11701210

RESUMO

The influence of oral adsorbent AST-120 (Kremezin) on the anticonvulsive effect and pharmacokinetics of zonisamide was investigated. Oral administration of zonisamide (50 mg/kg) blocked the appearance of the tonic extension induced by maximal electroshock seizure. This effect of zonisamide was inhibited by the oral coadministration of AST-120 (5 g/kg). In pharmacokinetics study, the serum zonisamide concentration after coadministration of zonisamide and AST-120 was significantly lower than that of single administration of zonisamide. However, the anticonvulsive effect of zonisamide was not affected by the administration of AST-120 1.5 h after zonisamide administration. In this condition, the serum zonisamide concentration was not changed. In the in vitro study, AST-120 completely adsorbed zonisamide. These findings suggest that when AST-120 is administered concurrently with zonisamide, a significant inhibition of the anticonvulsive effect of zonisamide occurs, and the decrease in serum zonisamide concentration by the adsorption effect of AST-120 is related to this phenomenon.


Assuntos
Anticonvulsivantes/farmacologia , Carbono/administração & dosagem , Isoxazóis/farmacologia , Óxidos/administração & dosagem , Administração Oral , Adsorção/efeitos dos fármacos , Animais , Anticonvulsivantes/antagonistas & inibidores , Anticonvulsivantes/sangue , Interações Medicamentosas/fisiologia , Eletrochoque , Isoxazóis/antagonistas & inibidores , Isoxazóis/sangue , Masculino , Ratos , Ratos Wistar , Convulsões/tratamento farmacológico , Zonisamida
13.
J Int Acad Periodontol ; 3(2): 42-7, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12666977

RESUMO

Epileptic patients taking phenytoin with gingival-overgrowth and those without gingival-overgrowth were compared for daily drug dose, plasma total phenytoin concentration, plasma free-phenytoin concentration and serum IgG antibody titre against 13 periodontal bacteria. Significantly higher daily drug dose was noted in patients with gingival overgrowth (P < 0.05) when compared with those without overgrowth. In addition, both total and free forms of plasma phenytoin concentration were significantly higher in sera of patients with gingival growth than of those without overgrowth (P < 0.01). Strong positive correlation was found between daily drug dose and serum phenytoin concentration in patients with gingival overgrowth, while weak correlation was found in patients without gingival overgrowth, suggesting a difference in drug metabolism in these two groups. However, no differences were found in serum IgG antibody titres to 13 periodontal bacteria examined between two groups. These results suggest that metabolic ability of phenytoin is one of the factors for developing gingival overgrowth, and that periodontal infection may not be a primary causative factor for gingival overgrowth but act as an additive factor which increase tissue mass for this unwanted side effect.


Assuntos
Anticorpos Antibacterianos/sangue , Anticonvulsivantes/sangue , Crescimento Excessivo da Gengiva/induzido quimicamente , Bactérias Gram-Negativas/imunologia , Imunoglobulina G/sangue , Fenitoína/sangue , Administração Oral , Adolescente , Adulto , Idoso , Aggregatibacter actinomycetemcomitans/imunologia , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/efeitos adversos , Bacteroides/imunologia , Campylobacter/imunologia , Capnocytophaga/imunologia , Eikenella corrodens/imunologia , Epilepsia/tratamento farmacológico , Feminino , Fusobacterium nucleatum/imunologia , Crescimento Excessivo da Gengiva/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Fenitoína/administração & dosagem , Fenitoína/efeitos adversos , Porphyromonas gingivalis/imunologia , Prevotella intermedia/imunologia , Fatores de Risco , Estatística como Assunto , Treponema/imunologia
14.
Pathol Int ; 50(3): 238-43, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10792788

RESUMO

Myoepithelioma of the lacrimal gland is extremely rare and only four cases, one of which was malignant, have been reported in detail. The present report describes a case of lacrimal gland myoepithelioma in a Japanese male with histological features suggestive of potentially malignant transformation. The excised tumor consisted of two components, a central nodular component and a peripheral component surrounding the former. These components were separated by a fibrous tissue. Microscopically, both components were comprised almost entirely of spindle-shaped cells, but with some epithelioid cells containing glycogen granules. Extracellular spaces in the peripheral component were filled with eosinophilic materials with the occasional crystalloid structures, which were immunoreactive for collagen type I. Neoplastic cells were immunoreactive focally for vimentin and S-100, but negative for cytokeratins, epithelial membrane antigen, muscle actin, smooth muscle actin, desmin, myosin, and glial fibrillary acidic protein. The neoplastic cells in the central component showed nuclear pleomorphism and atypia with a higher frequency of mitotic figures, and higher labelings of proliferation markers than those in the peripheral component. Neither invasion, necrosis, nor hemorrhage was observed in the tumor. From these findings we proposed a diagnosis of potentially malignant myoepithelioma.


Assuntos
Doenças do Aparelho Lacrimal/patologia , Mioepitelioma/patologia , Neoplasias Orbitárias/patologia , Adulto , Humanos , Doenças do Aparelho Lacrimal/fisiopatologia , Masculino , Mioepitelioma/fisiopatologia , Neoplasias Orbitárias/fisiopatologia
15.
Leuk Lymphoma ; 39(5-6): 641-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11342348

RESUMO

Here we report a case with precursor natural killer (NK) cell leukemia successfully treated with an unrelated cord blood transplantation. A 7-month-old Japanese boy was diagnosed to have NK cell leukemia based on the existence of abnormal cells in the bone marrow with the phenotype of CD3(-) /CD4(+) /CD7(-) /CD8(-) /CD16(-) /CD33(+) /CD34(-) /CD56(+) /HLA-DR(+) /NKB1(+) / CD94(+). The leukemic cells showed few azurophilic granules in the cytoplasm and weak cytotoxic activity. Although he presented with a huge mass occupying the bilateral paranasal sinuses and hepatosplenomegaly, he achieved complete remission by the conventional chemotherapeutic regimen for acute myelogenous leukemia, followed by an unrelated cord blood transplantation. He has remained in complete remission for 14 months posttransplant. To our knowledge, this is the youngest reported case with precursor NK cell leukemia; cord blood transplantation may thus be the treatment of choice for this disease.


Assuntos
Sangue Fetal/citologia , Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais/patologia , Leucemia de Células T/terapia , Intervalo Livre de Doença , Histocompatibilidade , Humanos , Imunofenotipagem , Lactente , Japão , Leucemia de Células T/diagnóstico , Masculino , Transplante Homólogo
16.
J Chromatogr B Biomed Sci Appl ; 723(1-2): 301-5, 1999 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-10080659

RESUMO

Plasma phenobarbital (PB) concentrations in rat offspring were determined using a 9 microl capillary by high-performance liquid chromatography (HPLC). Capillary plasma which was put into a Bond Elut cartridge column by using 1 ml of 0.01 M KH2PO4 was applied to the column with 50 microl of 2 microg/ml of acetanilide (internal standard, I.S.). After washing the column, PB and I.S. were eluted with methanol and injected into the HPLC system. There were excellent linear correlation between the amount of PB and length of the capillary at three different concentrations. Calibration for PB was linear in the range of 0-50 microg/ml. The coefficients of variation were 3.4-5.0% and 5.9-7.5% in the within-day and between-day assays, respectively. The extraction recovery rates were 87.5-105.4%. By this method, it was possible to measure plasma PB concentrations in rat offspring without killing. These results suggested that this method is very useful to determine the plasma PB concentration derived from mother's milk in newborn rats.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Fenobarbital/sangue , Animais , Animais Recém-Nascidos , Calibragem , Feminino , Leite/química , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Pharm Biomed Anal ; 19(3-4): 585-93, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10704124

RESUMO

Response characteristics of mexiletine-sensitive membrane electrodes based on crown ether and ion-exchanger were examined in a physiological saline in order to find an electrode suitable for determining concentrations of this drug under physiological conditions. Among various crown ethers screened, 4',4"(5")-di-tert-butyldicyclohexano-18-crown6 showed the highest sensitivity to mexiletine in physiological saline containing 0.15 M NaCl and 5 mM 4-(2-hydroxyethyl)-2-piperazineethanesulfonic acid (Hepes) NaOH (pH 7.4). However, the detection limit of 30 microM was 10 times higher than that of 3 microM observed with the electrode based on an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate. Having high selectivity against inorganic cations such as Na+ or K+, the electrode using the ion-exchanger enabled us to determine the level of mexiletine in saliva, the monitoring of which is quite effective for controlling the dose of this drug noninvasively. The mexiletine concentrations determined with the mexiletine electrode compared favourably with those determined by high-performance liquid chromatography which requires an additional procedure to extract mexiletine from saliva.


Assuntos
Antiarrítmicos/análise , Éteres de Coroa , Eletrodos Seletivos de Íons , Membranas Artificiais , Mexiletina/análise , Boratos/química , Calibragem , Cromatografia Líquida de Alta Pressão , Éteres Cíclicos/química , HEPES/química , Humanos , Canais Iônicos , Reprodutibilidade dos Testes , Saliva/química , Sensibilidade e Especificidade , Fatores de Tempo
18.
Free Radic Biol Med ; 27(11-12): 1313-23, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10641726

RESUMO

Lipid hydroperoxide (LOOH)-dependent lipid peroxidation was induced in alpha-linolenic acid (LNA)-loaded hepatocytes by adding Fe, Cu, V, or Cd ions at concentrations from 20 to 500 microM. The effects of structurally related flavonoids at concentrations from 10 to 500 microM on the lipid peroxidation were examined. The results with regard to each flavonoid subclass are as follows: (i) Flavonols such as myricetin, quercetin, fisetin, and kaempferol, but not morin, showed dose-dependent antioxidative activity against metal-induced lipid peroxidation at all metal concentrations. Myricetin, quercetin, and fisetin were the most effective antioxidants, although their efficacies depended on the metal ion. Kaempferol and morin had antioxidative activity equal to the other flavonols in the presence of Cu ions, but were much less effective for the other three metal ions. (ii) Flavones, luteolin, apigenin, and chrysin were antioxidative at low Fe concentrations, but were pro-oxidative at high Fe concentrations. Luteolin exhibited antioxidative activity similar to that of catechol-containing flavonols in the presence of the other three metal ions. Apigenin and chrysin also acted as pro-oxidants with V or with all metal ions, respectively. (iii) Taxifolin, a flavanone, also showed both anti- and prooxidative activity, depending on Fe concentrations, but with other metal showed only antioxidative activity ions. (iv) Epigallocatechin, a flavanol, was antioxidative with all metal ions, and its activity was similar to that of catechol-containing flavonols. The various effects of flavonoids on metal-induced lipid peroxidation in LNA-loaded hepatocytes is discussed with regard to the change in redox potential of flavonoid-metal complexes.


Assuntos
Antioxidantes/farmacologia , Flavonoides/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Metais/farmacologia , Ácido alfa-Linolênico/farmacologia , Animais , Cádmio/farmacologia , Cobre/farmacologia , Flavonóis , Ferro/farmacologia , Peróxidos Lipídicos/farmacologia , Fígado/efeitos dos fármacos , Masculino , Oxidantes/farmacologia , Quercetina/análogos & derivados , Quercetina/farmacologia , Ratos , Ratos Wistar , Vanádio/farmacologia
19.
Pharmacol Toxicol ; 83(4): 176-82, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9820879

RESUMO

Addition of more than 10 microM of adriamycin to cultured rat hepatocytes loaded with alpha-linolenic acid (linolenic acid-loaded hepatocytes) caused marked lipid peroxidation as measured by an accumulation of malondialdehyde during a 9 hr incubation. After addition of 50 microM of adriamycin to linolenic acid-loaded hepatocytes, malondialdehyde accumulation significantly increased at 3 hr, followed by cellular reduced glutathione decrease and lactate dehydrogenase leakage after 6 hr. Inhibition of adriamycin-induced lipid peroxidation by addition of N,N'-diphenyl-p-phenylenediamine or alpha-tocopherol, both lipid radical scavengers, or deferoxamine, which is a Fe ion chelator, prevented both glutathione decrease and lactate dehydrogenase leakage, indicating that lipid peroxidation caused cellular damage to linolenic acid-loaded hepatocytes exposed to adriamycin. The effect of SKF 525-A, which is a cytochrome P450 inhibitor, on adriamycin-induced lipid peroxidation and on 7-ethoxycoumarin O-deethylase activity was determined by 6 hr incubation of linolenic acid-loaded cells. Addition of SKF 525-A suppressed adriamycin-induced lipid peroxidation comparably with its 7-ethoxy-coumarin 0-deethylase inhibitory activity. These results suggest that cytochrome P450 contributes to the one-electron bioreduction of adriamycin into its semiquinone radical in rat hepatocytes.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Ácido alfa-Linolênico/metabolismo , O-Dealquilase 7-Alcoxicumarina/antagonistas & inibidores , O-Dealquilase 7-Alcoxicumarina/metabolismo , Animais , Antioxidantes/farmacologia , Células Cultivadas , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Desferroxamina/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/metabolismo , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Fenilenodiaminas/farmacologia , Proadifeno/farmacologia , Ratos , Ratos Wistar , Vitamina E/farmacologia
20.
Acta Med Okayama ; 52(3): 139-42, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9661740

RESUMO

Steady-state serum concentrations of carbamazepine (CBZ) and valproic acid (VPA) were investigated in normal weight (body mass index; BMI 20 to 25), lean (smaller than 20 BMI) and moderately obese subjects (greater than 25 BMI) who received either 400 mg/day of CBZ or 800 mg/day of VPA. The CBZ serum concentration in lean subjects was significantly higher than that in normal weight subjects. However, no significant differences in VPA serum concentration were found between the three groups. The CBZ serum concentration decreased with increases in total body weight, and the VPA serum concentration decreased with increases in ideal body weight. However, both serum concentrations were not correlated with BMI. These results suggest that VPA doses should be calculated using ideal body weight and that degree of obesity may affect CBZ serum concentration rather than VPA serum concentration.


Assuntos
Anticonvulsivantes/farmacocinética , Carbamazepina/farmacocinética , Epilepsia/tratamento farmacológico , Ácido Valproico/farmacocinética , Adolescente , Adulto , Anticonvulsivantes/sangue , Carbamazepina/sangue , Epilepsia/sangue , Feminino , Humanos , Modelos Lineares , Masculino , Ácido Valproico/sangue
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