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1.
Rhinology ; 61(3): 263-271, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36891983

RESUMO

BACKGROUND: Tripartite motif-containing 27 (TRIM27) has been implicated in the progression of various cancers. However, the role of TRIM27 in sinonasal mucosal melanoma (SNMM) remains poorly understood. MATERIALS & METHODS: We retrospectively examined 28 patients with SNMM treated with between 2003 and 2021. We undertook immunohistochemical analysis of TRIM27, Ki-67, and p-Akt1 expression in SNMM tissues. We also investigated the relationship between TRIM27 expression and clinical characteristics, prognosis, Ki-67 as a tumor growth potential marker, and p-Akt1 as one of the prognostic factors in mucosal melanoma. RESULTS: TRIM27 expression was significantly higher in T4 disease than in T3 disease and was higher in stage IV than in stage III. Patients with high-TRIM27 SNMM had a significantly poorer prognosis in terms of overall survival (OS) and disease-free survival.There was also a significantly higher rate of distant metastasis. Univariate analysis for OS revealed that TRIM27 and T classification were significant poor prognostic factors. In addition, the Ki-67 positive score and the p-Akt1 total staining score were significantly higher in the high-TRIM27 group than in the low-TRIM27 group. CONCLUSIONS: High TRIM27 expression in SNMM was associated with advanced T classification, poor prognosis and distant metastasis. We suggest that TRIM27 has potential as a novel biomarker for prognosis in SNMM.


Assuntos
Melanoma , Neoplasias dos Seios Paranasais , Humanos , Estudos Retrospectivos , Antígeno Ki-67 , Neoplasias dos Seios Paranasais/patologia , Prognóstico , Proteínas de Ligação a DNA , Proteínas Nucleares
2.
Rhinology ; 58(5): 451-459, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32542237

RESUMO

BACKGROUND: Zinc plays an important role in many biological processes. Reduced zinc levels have been found in chronic rhinosinusitis (CRS) patients, however, its role in the pathophysiology of this disease remains unknown. This study examined zinc levels in the serum, mucus and tissue from CRS patients in relation to collagen content and eosinophil infiltration. The effect of zinc depletion on inflammatory cytokine production and collagen synthesis was assessed in vitro. METHODOLOGY: Zinc levels were determined in serum, mucus and tissue from controls, CRS with (CRSwNP) and without nasal polyps (CRSsNP) patients. Tissue zinc levels, collagen and inflammatory cell infiltration was examined using zinquin assays, immunofluorescence and histology on Tissue Micro Arrays. Cytokine expression and collagen synthesis was evaluated in zinc depleted primary human nasal epithelial cells (HNECs) and primary fibroblasts. RESULTS: CRSwNP patients showed reduced tissue zinc levels in correlation with a reduction in collagen content, and increased eosinophil numbers. Zinc depletion of HNECs and fibroblasts induced the production of pro-inflammatory cytokines and MUC5AC and reduced collagen secretion. CONCLUSIONS: These results suggest mucosal zinc depletion associates with tissue eosinophilia and collagen depletion in CRSwNP and induces pro-inflammatory cytokine expression and reduction of collagen synthesis in vitro.


Assuntos
Colágeno , Eosinofilia , Pólipos Nasais , Rinite , Zinco , Doença Crônica , Colágeno/metabolismo , Eosinófilos , Humanos , Zinco/metabolismo
3.
Clin Exp Allergy ; 48(9): 1137-1146, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29781543

RESUMO

BACKGROUND: A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor. OBJECTIVE: This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma. METHODS: We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status." RESULTS: Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05). CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."


Assuntos
Asma/epidemiologia , Adolescente , Adulto , Asma/diagnóstico , Biomarcadores , Criança , Pré-Escolar , Comorbidade , Progressão da Doença , Feminino , Seguimentos , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Óxido Nítrico , Fenótipo , Prognóstico , Testes de Função Respiratória , Índice de Gravidade de Doença , Inquéritos e Questionários , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adulto Jovem
4.
J Exp Med ; 186(4): 489-95, 1997 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-9254647

RESUMO

Estrogen deficiency causes bone loss, which can be prevented by estrogen replacement therapy. Using a recently developed technique for isolation of highly purified mammalian osteoclasts, we showed that 17 beta-estradiol (E2) was able to directly inhibit osteoclastic bone resorption. At concentrations effective for inhibiting bone resorption, E2 also directly induced osteoclast apoptosis in a dose- and time-dependent manner. ICI164,384 and tamoxifen, as pure and partial antagonists, respectively, completely or partially blocked the effect of E2 on both inhibition of osteoclastic bone resorption and induction of osteoclast apoptosis. These data suggest that the protective effects of estrogen against postmenopausal osteoporosis are mediated in part by the direct induction of apoptosis of the bone-resorbing osteoclasts by an estrogen receptor- mediated mechanism.


Assuntos
Apoptose/efeitos dos fármacos , Reabsorção Óssea/prevenção & controle , Estrogênios/farmacologia , Osteoclastos/efeitos dos fármacos , Animais , Osteoclastos/fisiologia , Coelhos , Receptores de Estrogênio/fisiologia
5.
J Environ Radioact ; 99(6): 1003-10, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18164522

RESUMO

Sorption behavior of tin (Sn) in Japanese agricultural soils was studied. Soil-soil solution distribution coefficient (K(d)) of Sn (K(d)-Sn) for 142 soil samples ranged between 128 and 1,590,000 L kg(-1) with the geometric mean of 12 400 L kg(-1). The K(d)-Sn values for Andosol tended to be higher than those of the other soil groups. Among the relationships between K(d)-Sn values and soil properties, a high correlation was observed for soil active-Al (Al-(hydr)oxide and Al-humus complex) amount and K(d)-Sn. The pH effect on Sn sorption was also investigated. The results suggested that the low pH condition enhanced the Sn sorption in soils. The soil-sorbed Sn fractions in each type of soil material were also evaluated with selective extraction methods. The results showed that most of the soil-sorbed Sn was as organic matter bound or Al/Fe-(hydr)oxide-bound forms.


Assuntos
Poluentes do Solo/química , Solo/análise , Estanho/química , Adsorção , Agricultura , Alumínio/química , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Japão
6.
J Laryngol Otol ; 130(12): 1147-1152, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27804898

RESUMO

OBJECTIVE: This study aimed to predict eosinophilic chronic rhinosinusitis prognosis by investigating changes in the blood eosinophil count and other disease biomarkers after surgery. METHODS: Blood eosinophil numbers and serum interleukin-5 levels were measured in 22 eosinophilic chronic rhinosinusitis patients before and after functional endoscopic sinus surgery, and compared with equivalent measures in non-eosinophilic chronic rhinosinusitis patients and chronic rhinosinusitis without polyps patients. Differences between well-controlled eosinophilic chronic rhinosinusitis patients and those who experienced recurrence were also assessed. RESULTS: Blood eosinophil numbers and serum interleukin-5 level decreased after surgery in eosinophilic chronic rhinosinusitis patients. In this patient group, blood eosinophil counts before surgery were significantly higher in patients who experienced recurrence (825.7 ± 26.1 vs 443.9 ± 76.6 cells/µl, p < 0.05), and decreased significantly after surgery (825.7 ± 26.1 vs 76.7 ± 25.8 cells/µl, p < 0.05). CONCLUSION: Blood eosinophil numbers may reflect disease severity in eosinophilic chronic rhinosinusitis patients and their prognosis after surgery.


Assuntos
Eosinofilia/sangue , Interleucina-5/sangue , Seios Paranasais/cirurgia , Rinite/cirurgia , Sinusite/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Endoscopia , Eosinofilia/imunologia , Eosinófilos , Feminino , Humanos , Interleucina-5/imunologia , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Prognóstico , Rinite/sangue , Rinite/imunologia , Sinusite/sangue , Sinusite/imunologia , Resultado do Tratamento , Adulto Jovem
7.
Biochim Biophys Acta ; 1341(2): 207-16, 1997 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-9357960

RESUMO

The interaction of bromocresol purple (BCP) anions with bovine serum albumin (BSA) was investigated by principal factor analysis method, and reaction model, the number of molecular species and spectra of each component present in the reaction mixture were determined. The number of molecular species concerning the absorption intensity was three, including free BCP anion. Most part of the spectral change could be explained by the monomer binding of bromocresol purple anion (D) to serum albumin (P), a simple one step equilibrium, P + D = PD. A second type of association of BCP anions with serum albumin was also present, though in a small amount. Of six models tested which consisted of three or four molecular species, the sequential two step reaction model, P = PD = PD2, was the best model to explain the spectral data, and an existence of BCP anions as a dimer on the serum albumin was demonstrated. The dissociation constants were estimated at K1 = 1.6 x 10(-6) M for the first step and K2 = 1.2 x 10(-5) M for the second step.


Assuntos
Púrpura de Bromocresol/metabolismo , Soroalbumina Bovina/metabolismo , Simulação por Computador , Dimerização , Ligação Proteica , Espectrofotometria
8.
Biochim Biophys Acta ; 1480(1-2): 321-8, 2000 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-10899633

RESUMO

The most fundamental parameters concerning an interaction between a ligand and a protein are equilibrium constants and the number of binding sites. The Scatchard plot has for a long time been widely used to obtain those parameters. However, controversy in 1982-1983 over the reliability of this plot (the graphical estimation of the number of identical independent sites from the x-intercept) indicated that some methodologies other than the Scatchard plot are expected. Over the past decade, we have developed a method for applying multivariate analysis to the problem of determining spectral features of a ligand associated with a protein molecule. In principle, this method is based mainly on the computer-assisted adjustment of dissociation constants to an assumed reaction model. We discovered in this process that an n-parameter, introduced into an equation for calculating the amount of dye ligand bound to a protein, coincided with the number of identical independent sites, under a certain condition in principal factor analysis calculation. In this study, we established a new methodology for determining the number of identical independent sites using synthesized spectral series, and we then applied this method to a simple reaction system composed of bovine serum albumin (BSA) and bromocresol purple (BCP) anions. BSA was found to have two identical independent sites for BCP anions at pH 8.8.


Assuntos
Corantes/metabolismo , Soroalbumina Bovina/metabolismo , Animais , Sítios de Ligação , Bovinos , Análise Fatorial , Ligantes , Análise Multivariada , Soroalbumina Bovina/química , Espectrofotometria Ultravioleta
9.
J Gen Physiol ; 59(1): 22-32, 1972 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-5007263

RESUMO

Calcium release and binding produced by alterations in pH were investigated in isolated sarcoplasmic reticulum (SR) from skeletal muscle. When the pH was abruptly increased from 6.46 to 7.82, after calcium loading for 30 sec, 80-90 nanomoles (nmole) of calcium/mg protein were released. When the pH was abruptly decreased from 7.56 to 6.46, after calcium loading for 30 sec, 25-30 nmole of calcium/mg protein were rebound. The calcium release process was shown to be a function of pH change: 57 nmole of calcium were released per 1 pH unit change per mg protein. The amount of adenosine triphosphate (ATP) bound to the SR was not altered by the pH changes. The release phenomenon was not due to alteration of ATP concentration by the increased pH. Native actomyosin was combined with SR in order to study the effectiveness of calcium release from the SR by pH change in inducing super-precipitation of actomyosin. It was found that SR, in an amount high enough to inhibit superprecipitation at pH 6.5, did not prevent the process when the pH was suddenly increased to 7.3, indicating that the affinity of SR for calcium depends specifically on pH. These data suggest the possible participation of hydrogen ion concentration in excitation-contraction coupling.


Assuntos
Cálcio/metabolismo , Concentração de Íons de Hidrogênio , Retículo Sarcoplasmático/metabolismo , Actomiosina/isolamento & purificação , Trifosfato de Adenosina/farmacologia , Animais , Isótopos de Carbono , Precipitação Química , Cães , Técnicas In Vitro , Contração Muscular , Cloreto de Potássio
10.
Leukemia ; 11 Suppl 3: 245-6, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9209354

RESUMO

To examine the pathogenic roles of HTLV-I in HTLV-I-induced diseases, we developed two models; namely HTLV-I carrier rats and HTLV-I env-pX transgenic rats. Among life long HTLV-I carriers in seven rat strains, only WKAH rats with the RT1k haplotype developed chronic progressive myeloneuropathy, resembling HAM/TSP clinically and histologically in humans, designated as HAM rat disease and after long incubation periods. Apoptosis of myelin forming cells, oligodendrocytes and Schwann cells associated with HTLV-I infection appears to be the primary cause of HAM rat disease. Local activation of the pX gene and TNF alpha gene was evident in these rats. WKAH rats transgenic for HTLV-I env-pX gene were established and at age 5 weeks, swelling of the bilateral ankle joints began to develop and histological features of the affected joints resembled findings in cases of rheumatoid arthritis (RA): high-titers of rheumatoid factors were present in these rats. A series of vascular collagen diseases such as polyarteritis nodosa-like angiitis, polymyositis, myocarditis, and Sjögren's syndrome-like sialodenitis together with RA were present, even in one individual animal. These transgenic rats as well as HAM rats appear to be suitable animal models for elucidating pathogenic mechanisms implicated in HTLV-I-induced diseases and also various demyelinating vascular collagen diseases of unknown etiology.


Assuntos
Genes env , Infecções por HTLV-I/transmissão , Vírus Linfotrópico T Tipo 1 Humano/genética , Paraparesia Espástica Tropical/transmissão , Proteínas Oncogênicas de Retroviridae/genética , Fatores de Transcrição , Animais , Animais Geneticamente Modificados , Artrite Reumatoide/fisiopatologia , Portador Sadio , Modelos Animais de Doenças , Regulação da Expressão Gênica , Produtos do Gene env/biossíntese , Produtos do Gene env/genética , Infecções por HTLV-I/fisiopatologia , Paraparesia Espástica Tropical/fisiopatologia , Ratos , Ratos Endogâmicos , Proteínas Oncogênicas de Retroviridae/biossíntese , Fator Reumatoide/análise , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Virais Reguladoras e Acessórias
11.
Dentomaxillofac Radiol ; 44(9): 20150074, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26054571

RESUMO

OBJECTIVES: To investigate the diagnostic value of tumour blood flow (TBF) obtained with pseudocontinuous arterial spin labelling for the differentiation of squamous cell carcinoma (SCC) and inverted papilloma (IP) in the nasal or sinonasal cavity. METHODS: We retrospectively analysed the cases of 33 patients with SCC and 8 patients with IP in the nasal or sinonasal cavity. Pseudocontinuous arterial spin labelling scanning was performed for all patients using a 3.0-T MR unit. Quantitative TBF values were measured by two neuroradiologists by respectively delineating the whole-tumour regions of interest, and the mean of them was determined as TBF value in each patient. Additionally, the presence of imaging findings of convoluted cerebriform pattern (CCP) on MR T2 weighted images was determined in all patients. As a subgroup analysis, patients with IP were divided into aggressive and non-aggressive IPs depending on their progression range. First, an intraclass correlation coefficient (ICC) of TBF values between two neuroradiologists was determined. Next, a statistical comparison of the TBF value by a Mann-Whitney U test between the patients with SCC and IP was performed. Additionally, the comparison by an ANOVA with a post hoc test of Tukey's method among the SCC, non-aggressive IP and aggressive IP groups was also performed. If significance was observed, the diagnostic accuracy to differentiate SCCs from IPs was calculated. Diagnostic accuracy by CCP findings alone and by the combination of CCP findings and TBF were also assessed. RESULTS: The ICC of TBF values between two neuroradiologists was 0.82. The mean TBF values in the patients with SCC, all patients with IP, those with aggressive IP and those with non-aggressive IP were 141.2 ± 33.1, 77.8 ± 31.5, 109.4 ± 16.7 and 58.8 ± 19.9 ml 100 g⁻¹ min⁻¹, respectively. A significant difference was observed between SCC and IP (p < 0.001), SCC and non-aggressive IP (p < 0.01) and non-aggressive IP and aggressive IP (p < 0.01). The diagnostic accuracy values obtained with receiver operating characteristic curve analysis for the differentiation of SCC from IP and for SCC from non-aggressive IP were 0.90 and 0.92, respectively. The diagnostic accuracy was elevated (0.95 from 0.88) by adding the TBF value to CCP findings. CONCLUSIONS: The pseudocontinuous arterial spin labelling technique can be a useful non-invasive diagnostic tool to differentiate SCC from IP in nasal or sinonasal cavity.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Papiloma Invertido/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Carcinoma de Células Escamosas/irrigação sanguínea , Diagnóstico Diferencial , Imagem Ecoplanar/métodos , Imagem Ecoplanar/estatística & dados numéricos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Invasividade Neoplásica , Neoplasias Nasais/irrigação sanguínea , Neoplasias Nasais/diagnóstico , Papiloma Invertido/irrigação sanguínea , Neoplasias dos Seios Paranasais/irrigação sanguínea , Neoplasias dos Seios Paranasais/diagnóstico , Curva ROC , Fluxo Sanguíneo Regional/fisiologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Marcadores de Spin , Técnica de Subtração
12.
J Bone Miner Res ; 12(8): 1165-73, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9258746

RESUMO

To address the relation between osteoblast growth and cell-to-cell communication, we examined the effects of basic fibroblast growth factor (bFGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA), both potent stimulators of osteoblastic proliferation, on gap junctional intercellular communication between osteoblastic MC3T3-E1 cells. The level of intercellular communication was estimated by a photobleaching method. TPA inhibited the degree of intercellular communication in two different time-dependent manners. The early (< 1 h) inhibition by TPA was consistent with an increase in the phosphorylation of connexin 43 (Cx43). The later inhibition was caused by reduction in the total amount of Cx43 on the plasma membrane, due to the decrease in the level of Cx43 transcripts. These qualitative and quantitative modulations by TPA were inhibited by a selective inhibitor of protein kinase C, GF109203X. bFGF also attenuated the gap junctional intercellular communication. However, short exposure (< 5 h) to bFGF did not affect the communication. The fact that the growth factor immediately stimulated the phosphorylation of Cx43 indicates that the phosphorylation site(s) affected by bFGF was not involved in the inhibition of communication. The decrease in the intercellular communication level was detected by the longer exposure (> 8 h) to bFGF and paralleled the decline in the Cx-mRNA level. This inhibitory effect of bFGF was abolished by the addition of a tyrosine kinase inhibitor, herbimycin A. Thus, gap junctional intercellular communication between osteoblasts was down-regulated by osteoblastic mitogens through different mechanisms of the modulation of Cx43.


Assuntos
Carcinógenos/toxicidade , Comunicação Celular/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/toxicidade , Junções Comunicantes/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Acetato de Tetradecanoilforbol/toxicidade , Células 3T3/citologia , Células 3T3/efeitos dos fármacos , Animais , Northern Blotting , Western Blotting , DNA/biossíntese , Relação Dose-Resposta a Droga , Regulação para Baixo , Humanos , Indóis/toxicidade , Maleimidas/toxicidade , Camundongos , Osteoblastos/citologia , Proteína Quinase C/antagonistas & inibidores , Proteínas Recombinantes/toxicidade
13.
FEBS Lett ; 444(2-3): 170-2, 1999 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-10050752

RESUMO

The mechanosensitive channel with large conductance of Escherichia coli is the first to be cloned among stretch-activated channels. Although its activity was characterized by a patch clamp method, a physiological role of the channel has not been proved. The marine bacterium, Vibrio alginolyticus, is sensitive to osmotic stress and cell lysis occurs under osmotic downshock. We introduced an mscL gene into Vibrio alginolyticus, and the mechanosensitive channel with large conductance functions was found to alleviate cell lysis by osmotic downshock. This is the first report to show a physiological role of the mechanosensitive channel with large conductance.


Assuntos
Proteínas de Escherichia coli , Escherichia coli/metabolismo , Canais Iônicos/genética , Estresse Mecânico , Vibrio/metabolismo , Proteínas de Bactérias/genética , Escherichia coli/genética , Canais Iônicos/metabolismo , Canais Iônicos/fisiologia , Pressão Osmótica , Cloreto de Potássio/farmacologia , Cloreto de Sódio/farmacologia , Esferoplastos/metabolismo , Vibrio/genética
14.
J Biochem ; 82(5): 1189-95, 1977 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-591495

RESUMO

The mechanism of spectral shift and absorption intensity change of the divalent bromocresol purple (BCP) anion was further investigated and it was characterized as a spectrophotometric membrane probe. At high concentrations (1-40 mM), the absorption intensity of th BCP anion at 590 nm (monomer band) decreased markedly with increase of the dye concentration, while another absorption band appeared at 554 nm. Analysis of the change of absorption intensity showed that the mared decrease resulted from dimer formation of BCP (polymer formation at concentrations higher than 20 mM). Wavelengths of maximum absorption (lambdamax) of the BCP anion were determined in various solvents and comparison of these lambdamax's with lambdamax of the BCP anion bound to SR showed that the hydrophobicity of the area of BCP anion binding to SR corresponded to a refractive index of 1.429. While the BCP anion bound to SR showed a monomer spectrum, a dimer band appeared for the BCP anion bound to SR-Pi (phosphorylated protein) with a marked decrease in the absorption intensity at the monomer band, indicating that two polar groups, binding sites for the BCP anions, closely approached each other in the SR-Pi configuration.


Assuntos
Púrpura de Bromocresol , Cresóis , Compostos Organofosforados/metabolismo , Retículo Sarcoplasmático/ultraestrutura , Animais , Corantes , Matemática , Membranas/ultraestrutura , Coelhos , Espectrofotometria
15.
J Biochem ; 80(6): 1393-9, 1976 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14125

RESUMO

The intravesicular pH (pHi) of fragmented sarcoplasmic reticulum (SR) of the skeletal muscle was determined from the distribution of 5,5-dimethyl-2,4-oxazolidinedione (DMO), a weak organic acid, between the intra- and extravesicular spaces. The pHi's thus obtained were found to be slightly lower (0.02-0.17 pH unit) than the pH's of the external medium (pHe) at pH 6.5-8.5 in the presence of 105 mM KCl and 40 mM Tris-maleate buffer. The higher the pHe, the greater the pH gradient. When pHe was changed, pHi attained equilibrium within about 20 min, the time necessary for the separation of the SR by centrifugation. When 0.25 M sucrose and 5 mM Tris-maleate buffer were used instead of 105 mM KCl and 40 mM buffer, the pH gradient increased to 0.56. It was also demonstrated by direct measurements of pHe with a glass-electrode pH meter that K+ ions added to the external medium exchanged the intravesicular H+ ions. From these results it appears that the pH gradient across the SR membrane was at the Donnan equilibrium. In this state, the Donnan potentials corresponding to pH gradients of 0.17 and 0.56 were -9.3 and -30.6 mV, respectively.


Assuntos
Dimetadiona , Concentração de Íons de Hidrogênio , Oxazóis , Retículo Sarcoplasmático , Sítios de Ligação , Soluções Tampão , Membranas , Mesilatos , Polietilenoglicóis , Potássio , Sacarose
16.
J Biochem ; 91(2): 537-51, 1982 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6121795

RESUMO

The mechanism of dimeric binding of bromocresol purple (BCP) anions to Mg2+ + Ca2+-ATPase of the sarcoplasmic reticulum (SR) and the resulting partial inhibition of the ATPase activity were studied. BCP anions in three states, free monomer, bound monomer, and bound dimer, were spectrophotometrically calculated by solving simultaneous equations, delta A lambda 1-lambda 2 = sigma delta ai (epsilon i lambda 1-epsilon i lambda 2), and concentration changes of these states were analyzed. The addition of ATP caused an increase in the bound dimer and a decrease in the free monomer, but the change of the bound monomer was slight. The decrease in delta A (decrease phase) on the addition of ATP on dual-wavelength spectrophotometry at 585-610 nm was related to an increase in the amount of dimer bound to the SR membranes. The magnitude of the decrease phase increased with an increase in Mg2+ concentration and decreased with an increase in the concentration of Ca2+. BCP anions at the probe concentration partially inhibited the ATPase activity, and brought about a decrease in the ADP-sensitive E-P (E1P) and an increase in the ADP-insensitive E-P (E2P), though BCP anions did not affect the amount of total E-P. On elimination of Mg2+ at the steady-state E-P level both E2P and E2P . (BCP)2 were decomposed, suggesting that the enzyme form binding the BCP dimer was Mg . E-P. An increase in Mg2+ concentration increased E2P but an increase in Ca2+ concentration decreased E2P. Decomposition of E2P to P1 was inhibited by BCP anions. The following simple scheme was suggested to explain the partial inhibition of the ATPase activity, (Formula: see text). Application of BCP anions was discussed for use as a probe for Mg . E-P in the steady-state ATP hydrolysis.


Assuntos
Trifosfato de Adenosina , Púrpura de Bromocresol/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Cresóis/metabolismo , Magnésio/metabolismo , Retículo Sarcoplasmático/enzimologia , Animais , Ânions , Ligação Competitiva , ATPase de Ca(2+) e Mg(2+) , Hidrólise , Técnicas In Vitro , Fosforilação , Coelhos , Espectrofotometria
17.
J Biochem ; 81(2): 321-8, 1977 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-191440

RESUMO

The interaction of Pi with sarcoplasmic reticulum (SR) isolated from rabbit skeletal muscle was studied using bromocresol purple (BCP) as a probe and a dual-wavelength spectrophotometer. Two kinds of absorption-intensity changes controlled by a low concentration of Ca2+ (greater than 10(-6)M) were observed after addition of Pi; an increase phase (in the presence of Ca2+), and a decrease phase (in the presence of EGTA). The increase phase was rapid, Ca2+-dependent, Mg2+-enhanced (depressed by high Mg2+ concentration) and not inhibited by PCMB and was suggested to reflect the formation of an SR-Pi complex. The decrease phase was slower than the increase phase, and was strongly inhibited by the low concentration of Ca2+. It required Mg2+, and was completely inhibited by p-chloromercuribenzoate or deoxycholate. It was suggested to reflect the formation of SR-Pi (phosphorylated protein). ATP inhibited this phase by converting it completely to an SR-MgATP phase. PPi was effective for inducing the decrease phase but PPPi was not. From measurements of these phases, the association constants of the SR-Pi complex and SR-Pi at pH 8.8 in the reaction scheme, SR + Pi in equilibrium SR-Pi in equilibrium SR-Pi, were calculated as 5.4 X 10 M-1 and 1.8 X 10(3) M-1, respectively. From the completely different responses of SR-Pi and SR-Pi observed with BCP a marked difference in the conformations of these enzyme states was suggested.


Assuntos
Corantes/metabolismo , Fosfatos/metabolismo , Retículo Sarcoplasmático/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Cálcio/farmacologia , Cloromercurobenzoatos/farmacologia , Ácido Desoxicólico/farmacologia , Difosfatos/farmacologia , Ácido Egtázico/farmacologia , Magnésio/farmacologia , Músculos , Ligação Proteica , Coelhos , Espectrofotometria
18.
J Biochem ; 127(4): 603-10, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10739952

RESUMO

Merocyanine 540 (MC540) is a widely used dye probe for membranous environments. However, fundamental knowledge of the spectral features of this dye in aqueous and hydrophobic environments is still lacking. Such knowledge is important because biomembranes involve a hydrophobic environment surrounded by a hydrophilic environment. Because many investigations so far have been performed based on indistinct spectral estimations, the interpretation of the data obtained using this dye as a fluorescent transmembrane probe remains controversial. In order to determine the exact spectra in both aqueous and hydrophobic environments, we adopted principal factor analysis (PFA), a method of multivariate analysis. The PFA method can also determine the number of molecular species present in the reaction mixture, which is three in pure water and two in phospholipid suspension. Two of the species in both water and phospholipid suspension were the monomer and dimer. The third species in water was the trimer, but its amount was so small at 10 microM MC540 solution that the spectral data in water can be approximated neglecting this molecular species. The monomer spectrum changed its form markedly with a bathochromic shift when transferred from the water to phospholipid environment, whereas the dimer remained similar in its shape except for a remarkable red shift. In water, the dissociation constants, K(1) and K(2), for the assumed stacking-model reactions, M+M <--> M(2) and M+M(2) <--> M(3), were 3.1 x 10(-4) M and 5.7 x 10(-4) M, respectively. In the phospholipid environment, the dissociation constant K* for the assumed stacking-model reaction, M(*)+M(*) <--> *M(2), was 1.9x10(-5)M. The fluorescent intensities of MC540 were also measured in both water and phospholipid environments. A comparison based on the absorption and fluorescence spectra suggested that the temporal increase in the amount of the monomer on the excitable membrane contributes to the fluorescent intensity change observed in the transmembrane potential change.


Assuntos
Corantes Fluorescentes/química , Fosfolipídeos/química , Pirimidinonas/química , Conformação Molecular , Análise Multivariada , Fosfatidilcolinas/química , Espectrometria de Fluorescência , Espectrofotometria , Água/química
19.
Rhinology ; 34(3): 163-5, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8938886

RESUMO

The present study examined the association between various human leukocyte antigens (HLA) and cytoplasmic-antineutrophil cytoplasmic antibody (cANCA)-positive Wegener's granulomatosis (WG) in Japanese subjects to determine whether HLA antigens are involved in the pathogenesis of this disease. The study involved 16 subjects with cANCA-positive WG treated in our department. HLA-typing of the lymphocytes was performed using a lymphocyte microcytotoxicity assay. Of the subjects with cANCA-positive WG, 62.5% (10/16) were positive for HLA-DR9, as compared to 26% of the healthy control subjects. This HLA-DR9 elevation was statistically significant (p < 0.01, Pc < 0.05); we also noted a weaker association between HLA-B55 and cANCA-positive WG (p < 0.05). The results indicate that an association may exist between certain HLA-class allotypes and WG.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos/análise , Granulomatose com Poliangiite/imunologia , Antígenos HLA/análise , Estudos de Casos e Controles , Feminino , Granulomatose com Poliangiite/genética , Teste de Histocompatibilidade , Humanos , Masculino , Pessoa de Meia-Idade
20.
Auris Nasus Larynx ; 28 Suppl: S107-10, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11683327

RESUMO

OBJECTIVE: To investigate clinical manifestations of relapsing polychondritis and to clarify the significance of type II collagen antibody in the disease. METHODS: Clinical manifestations and antibody titers were examined in eight cases of relapsing polychondritis which had been treated at Otolaryngology Department, Hokkaido University during the eight years from 1991 to 1998. Anti-type II collagen antibody titer was measured by ELISA method. RESULTS: The most frequent symptom was auricular chondritis; it was seen in 88% (7/8) of the cases. Ocular symptom, nasal chondritis, arthritis, respiratory tract chondritis, and audio-vestibular symptom were also common in the cases. Compared with previous reports, no difference was recognized in the manifestation frequency. Considering none of the samples from the controls was positive for anti-type II collagen antibody, two samples from the disease group were positive. The antibody positive rate was 25% (2/8). CONCLUSION: Though the measurement of type II collagen antibody titer is not a decisive factor for detection of relapsing polychondritis, it is useful as one of the complementary factors for the diagnosis, since there is no specific test for this disease.


Assuntos
Policondrite Recidivante/diagnóstico , Adolescente , Adulto , Autoanticorpos/sangue , Colágeno Tipo II/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Policondrite Recidivante/sangue
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