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1.
Artículo en Inglés | MEDLINE | ID: mdl-29956665

RESUMEN

BACKGROUND: Cough is a common feature of asthma, which is often resistant to inhaled corticosteroids (ICSs). The pathophysiology of this refractoriness may differ between daytime and nighttime asthmatic cough. We sought to identify factors contributing to ICS-refractory daytime and nighttime asthmatic cough. METHODS: Sixty-seven patients with asthma presenting solely or predominantly with chronic cough were prospectively enrolled from April 2012 to December 2014. At baseline and 12 weeks after ICS treatment, the capsaicin cough threshold (C2, C5) and methacholine airway sensitivity and reactivity were examined. A visual analog scale (VAS) and numeric scores were used to evaluate daytime and nighttime cough symptoms separately. The Japanese version of the Leicester Cough Questionnaire was also completed. When either the VAS or numeric scores showed an improvement of ≥50% or ≥2 points, patients were considered responders to ICS treatment. RESULTS: Fifty-five patients were eligible for evaluation. Subjective cough indices improved significantly at 12 weeks after ICS treatment (P<.001). Multivariate analysis revealed that lower C2 significantly contributed to residual daytime cough (P=.04). Meanwhile, methacholine hyperreactivity and lower IgE levels were predictors of the nighttime residual cough (P=.002 and P=.03, respectively). CONCLUSIONS: Heightened cough reflex sensitivity is an independent factor of daytime asthmatic cough that is refractory to ICSs. In contrast, airway hyperreactivity and less atopic status contribute to ICS-refractory nighttime cough.


Asunto(s)
Asma/complicaciones , Tos/etiología , Administración por Inhalación , Corticoesteroides/uso terapéutico , Adulto , Anciano , Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Tos/tratamiento farmacológico , Resistencia a Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo
2.
Clin Exp Allergy ; 47(8): 998-1006, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28326636

RESUMEN

BACKGROUND: Genetic markers of susceptibility to asthma exacerbations in adults remain unclear. OBJECTIVE: To identify genetic markers of asthma exacerbations, particularly in patients with type-2 inflammatory endotype. METHODS: In this observational study of patients enrolled in the Kinki Hokuriku Airway disease Conference multicenter study, frequency of exacerbations requiring systemic corticosteroids during 2 years after enrolment and associated risk factors was determined. For genetic marker analysis, interleukin-4 receptor α (IL4RA) rs8832 and a disintegrin and metalloprotease 33 (ADAM33) S_2 (rs528557), T_1 (rs2280091), T_2 (rs2280090), and V_4 (rs2787094) variants were included. Elevated serum periostin levels at enrolment (≥95 ng/mL, defined as type-2 inflammatory endotype) were considered in the analysis. RESULTS: Among 217 patients who were successfully followed up for 2 years after enrolment, 60 patients showed at least one asthma exacerbation during the 2 years. Airflow limitation (%FEV1 <80%) and recent exacerbations but not genetic variants were identified as risk markers of exacerbations. A total of 27 patients showed type-2 inflammatory endotype (serum periostin ≥95 ng/mL at enrolment) and subsequent exacerbations; risk factors in these patients were airflow limitation (odds ratio, 6.51; 95% confidence interval (CI): 2.37-18.6; P=.0003), GG genotype of IL4RA rs8832 (odds ratio, 4.01; 95% CI: 1.47-11.0; P=.007), and A allele of ADAM33 T_2 (odds ratio, 2.81; 95% CI: 1.05-7.67; P=.04) by multivariate analysis. In addition, GG genotype of IL4RA rs8832 was associated with type-2 endotype, whereas A allele of ADAM33 T_2 was associated with mixed type of eosinophilic/type-2 and neutrophilic inflammations. CONCLUSIONS AND CLINICAL RELEVANCE: IL4RA and ADAM33 variants may be risk markers of asthma exacerbations in type-2 inflammatory endotype. Precise endotyping may facilitate the identification of genetic risk markers of asthma exacerbations.


Asunto(s)
Proteínas ADAM , Asma/sangre , Asma/genética , Subunidad alfa del Receptor de Interleucina-4 , Proteínas ADAM/sangre , Proteínas ADAM/genética , Adulto , Anciano , Asma/tratamiento farmacológico , Estudios de Seguimiento , Marcadores Genéticos , Humanos , Subunidad alfa del Receptor de Interleucina-4/sangre , Subunidad alfa del Receptor de Interleucina-4/genética , Persona de Mediana Edad , Factores de Riesgo
3.
Allergy ; 71(7): 1031-6, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26991116

RESUMEN

BACKGROUND: Allergic rhinitis, a known risk factor for asthma onset, often accompanies mouth breathing. Mouth breathing may bypass the protective function of the nose and is anecdotally considered to increase asthma morbidity. However, there is no epidemiological evidence that mouth breathing is independently associated with asthma morbidity and sensitization to allergens. In this study, we aimed to clarify the association between mouth breathing and asthma morbidity and allergic/eosinophilic inflammation, while considering the effect of allergic rhinitis. METHODS: This community-based cohort study, the Nagahama Study, contained a self-reporting questionnaire on mouth breathing and medical history, blood tests, and pulmonary function testing. We enrolled 9804 general citizens of Nagahama City in the Shiga Prefecture, Japan. RESULTS: Mouth breathing was reported by 17% of the population and was independently associated with asthma morbidity. The odds ratio for asthma morbidity was 1.85 (95% CI, 1.27-2.62) and 2.20 (95% CI, 1.72-2.80) in subjects with mouth breathing alone and allergic rhinitis alone, which additively increased to 4.09 (95% CI, 3.01-5.52) when mouth breathing and allergic rhinitis coexisted. Mouth breathing in nonasthmatics was a risk for house dust mite sensitization, higher blood eosinophil counts, and lower pulmonary function after adjusting for allergic rhinitis. CONCLUSION: Mouth breathing may increase asthma morbidity, potentially through increased sensitization to inhaled allergens, which highlights the risk of mouth-bypass breathing in the 'one airway, one disease' concept. The risk of mouth breathing should be well recognized in subjects with allergic rhinitis and in the general population.


Asunto(s)
Asma/epidemiología , Asma/etiología , Respiración por la Boca , Adulto , Anciano , Asma/diagnóstico , Biomarcadores , Estudios de Cohortes , Femenino , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Morbilidad , Oportunidad Relativa , Vigilancia de la Población , Pruebas de Función Respiratoria , Factores de Riesgo , Autoinforme
4.
Allergy ; 71(10): 1472-9, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27113353

RESUMEN

BACKGROUND: Omalizumab, a humanized anti-IgE monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum IgE levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. METHODS: In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum IgE levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. RESULTS: We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum IgE levels after 16 or 32 weeks of treatment. Reduced free serum IgE levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum IgE levels. CONCLUSION: Baseline serum periostin levels and serum free IgE levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment.


Asunto(s)
Antiasmáticos/uso terapéutico , Asma/sangre , Asma/tratamiento farmacológico , Moléculas de Adhesión Celular/sangre , Inmunoglobulina E/sangre , Omalizumab/uso terapéutico , Adulto , Anciano , Antiasmáticos/farmacología , Asma/diagnóstico , Asma/inmunología , Biomarcadores , Progresión de la Enfermedad , Femenino , Humanos , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Omalizumab/farmacología , Curva ROC , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
6.
Allergy ; 69(5): 668-73, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24673601

RESUMEN

BACKGROUND: In steroid-naive patients with asthma, several gene variants are associated with a short-term response to inhaled corticosteroid (ICS) treatment; this has mostly been observed in Caucasians. However, not many studies have been conducted for other ethnicities. Here, we aimed to determine the relationship between the annual decline in forced expiratory flow volume in one second (FEV1 ) and the variant of the glucocorticoid-induced transcript 1 gene (GLCCI1) in Japanese patients with asthma receiving long-term ICS treatment, taking into account the effect of high serum periostin levels, a known association factor of pulmonary function decline and a marker of refractory eosinophilic/Th2 inflammation. METHODS: In this study, 224 patients with asthma receiving ICS treatment for at least 4 years were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1, stress-induced phosphoprotein 1 (STIP1), and T gene on the decline in FEV1 of 30 ml/year or greater were determined. RESULTS: Besides the known contributing factors, that is, the most intensive treatment step, ex-smoking, and high serum periostin levels (≥95 ng/ml), the GG genotype of GLCCI1 rs37973, and not other SNPs, was independently associated with a decline in FEV1 of 30 ml/year or greater. When patients were stratified according to their serum periostin levels, the GG genotype of rs37973 was significantly associated with blood eosinophilia (≥250/µl) in the high serum periostin group. CONCLUSIONS: A GLCCI1 variant is a risk factor of pulmonary function decline in Japanese patients with asthma receiving long-term ICS treatment. Thus, GLCCI1 may be associated with response to ICS across ethnicities.


Asunto(s)
Asma/genética , Asma/fisiopatología , Variación Genética , Receptores de Glucocorticoides/genética , Administración por Inhalación , Corticoesteroides/administración & dosificación , Corticoesteroides/uso terapéutico , Anciano , Asma/tratamiento farmacológico , Asma/inmunología , Moléculas de Adhesión Celular/sangre , Eosinófilos/inmunología , Femenino , Volumen Espiratorio Forzado , Estudios de Asociación Genética , Proteínas de Choque Térmico/genética , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Pruebas de Función Respiratoria , Factores de Riesgo
7.
Clin Exp Allergy ; 43(6): 608-15, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23711122

RESUMEN

BACKGROUND: Epidemiological studies have shown that smoking increases the propensity for atopy and asthma. However, the effects of smoking on atopy and eosinophilic inflammation in asthmatics, including the elderly, remain unknown. OBJECTIVE: To determine the effects of smoking on serum immunoglobulin E (IgE) levels and eosinophilic inflammation in asthmatics of all ages. METHODS: The associations of serum IgE levels, blood eosinophil counts and fractional exhaled nitric oxide (FeNO) levels with smoking and age in steroid-naive asthmatics were cross-sectionally assessed (n = 307). Levels of sputum eosinophil and thymic stromal lymphopoietin (TSLP) that promotes Th2 inflammation were also analysed. Current smokers were excluded when analysing contributing factors of FeNO. RESULTS: Levels of serum IgE, blood eosinophil and FeNO decreased with increasing age in never-smokers, whereas decrease in serum IgE levels with increasing age was not observed in current smokers. In addition, current smoking was associated with higher blood eosinophil counts. In atopic asthmatics, age-related declines in serum IgE levels were less steep in ex-smokers than in never-smokers, and atopic ex-smokers with asthma showed higher blood eosinophil counts and higher FeNO irrespective of age. Lastly, sputum TSLP levels were associated with sputum eosinophil proportions and pack-years. Current and ex-smokers had higher TSLP levels than never-smokers. CONCLUSIONS AND CLINICAL RELEVANCE: In steroid-naive asthmatics, smoking may attenuate the age-related decrease in IgE levels and maintain eosinophilic inflammation, in which TSLP may be involved.


Asunto(s)
Eosinófilos/inmunología , Inmunoglobulina E/inmunología , Inflamación/inmunología , Fumar , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Asma/inmunología , Asma/metabolismo , Estudios Transversales , Citocinas/metabolismo , Espiración , Femenino , Compuestos Férricos/sangre , Humanos , Inmunoglobulina E/sangre , Inflamación/sangre , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Nitratos/sangre , Óxido Nítrico , Esputo/metabolismo , Adulto Joven , Linfopoyetina del Estroma Tímico
8.
Artículo en Inglés | MEDLINE | ID: mdl-21462801

RESUMEN

BACKGROUND: Effects of long-term treatment with inhaled corticosteroids (ICSs) on airway-wall thickness in patients with asthma remain unknown. OBJECTIVES: To determine whether airway-wall thickness consistently decreases after long-term ICS treatment, and to analyze factors contributing to long-term airway-wall changes in asthmatics. METHODS: A retrospective analysis of long-term changes in airway-wall thickness using computed tomography was performed in 14 patients with asthma. Wall area corrected by body surface area (WA/BSA) was examined at baseline, 12 weeks after the commencement of ICSs (second measurement), and at least 2 years (mean +/- SEM. 4.2 +/- 0.5) after the second measurement (third measurement). Mean +/- SEM changes in WA/BSA from the second to the third measurements were analyzed. RESULTS: The mean change in WA/BSA was not significant between the second and the third measurements (-0.27 +/- 0.59 mm2/m2/y). Overall, the changes were significantly associated with disease duration but not with other clinical indices. When the 14 patients were divided into 2 groups using a cutoff value of 0.32 mm2/m2/y for the mean change in WA/BSA, for the 5 patients whose WA/BSA exceeded this cutoff, daily ICS doses were not reduced and both forced expiratory volume in the first second (FEV1) and forced vital capacity decreased significantly. For the remaining 9 patients, daily ICS doses were reduced and long-term FEV1 values did not change. CONCLUSIONS: Despite long-term treatment with ICSs, airway-wall thickness did not consistently decrease. One possible mechanism underlying poor response to long-term treatment may be long-standing asthma.


Asunto(s)
Corticoesteroides/efectos adversos , Asma/diagnóstico por imagen , Sistema Respiratorio/patología , Tomografía Computarizada por Rayos X , Administración por Inhalación , Corticoesteroides/uso terapéutico , Adulto , Anciano , Asma/tratamiento farmacológico , Femenino , Humanos , Cuidados a Largo Plazo , Masculino , Persona de Mediana Edad , Sistema Respiratorio/efectos de los fármacos , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
9.
Clin Exp Allergy ; 39(2): 236-45, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19134015

RESUMEN

BACKGROUND: Isoprostanes are prostaglandin (PG)-like compounds synthesized by oxidative stress, not by cyclooxygenase, and increase in bronchoalveolar lavage fluid of patients with asthma. The airway inflammation implicated in this disease may be amplified by oxidants. Although isoprostanes are useful biomarkers for oxidative stress, the action of these agents on airways has not been fully elucidated. OBJECTIVE: This study was designed to determine the intracellular mechanisms underlying the effects of oxidative stress on airway smooth muscle, focused on Ca(2+) signalling pathways involved in the effect of 8-iso-PGF(2 alpha). METHODS: Using simultaneous recording of isometric tension and F(340)/F(380) (an indicator of intracellular concentrations of Ca(2+), [Ca(2+)]i, we examined the correlation between tension and [Ca(2+)]i in response to 8-iso-PGF(2 alpha) in the fura-2 loaded tracheal smooth muscle. RESULTS: Augmented tension and F(340)/F(380) by 8-iso-PGF(2 alpha) were attenuated by ICI-192605, an antagonist of thromboxane A(2) receptors (TP receptors). Moreover, D609, an antagonist of phosphatidylcholine-specific phospholipase C, markedly reduced both the tension and F(340)/F(380) induced by 8-iso-PGF(2 alpha), whereas U73122, an antagonist of phosphatidylinositol-specific phospholipase C, modestly inhibited them by 8-iso-PGF(2 alpha). SKF96365, a non-selective antagonist of Ca(2+) channels, markedly reduced both tension and F(340)/F(380) by 8-iso-PGF(2 alpha). However, diltiazem and verapamil, voltage-dependent Ca(2+) channel inhibitors, modestly attenuated tension although their reduction of F(340)/F(380) was not different from that by SKF96365. Y-27632, an inhibitor of Rho-kinase, significantly attenuated contraction induced by 8-iso-PGF(2 alpha) without reducing F(340)/F(380), whereas GF109203X and Go6983, protein kinase C inhibitors, did not markedly antagonize them although reducing F(340)/F(380) with a potency similar to Y-27632. CONCLUSION: 8-iso-PGF(2 alpha) causes airway smooth muscle contraction via activation of TP receptors. Ca(2+) mobilization by SKF96365- and D609-sensitive Ca(2+) influx and Ca(2+) sensitization by Rho-kinase contribute to the intracellular mechanisms underlying the action of 8-iso-PGF(2 alpha). Rho-kinase may be a therapeutic target for the physiologic abnormalities induced by oxidative stress in airways.


Asunto(s)
Señalización del Calcio/fisiología , Dinoprost/análogos & derivados , Músculo Liso/efectos de los fármacos , Tráquea/efectos de los fármacos , Tráquea/fisiología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacología , Amidas/farmacología , Animales , Hidrocarburos Aromáticos con Puentes/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Señalización del Calcio/efectos de los fármacos , Diltiazem/farmacología , Dinoprost/farmacología , Dioxanos/farmacología , Inhibidores Enzimáticos/farmacología , Estrenos/farmacología , Cobayas , Imidazoles/farmacología , Técnicas In Vitro , Indoles/farmacología , Masculino , Maleimidas/farmacología , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Músculo Liso/fisiología , Norbornanos , Piridinas/farmacología , Pirrolidinonas/farmacología , Receptores de Tromboxano A2 y Prostaglandina H2/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Tiocarbamatos , Tionas/farmacología , Fosfolipasas de Tipo C/antagonistas & inhibidores , Vasoconstrictores/farmacología , Verapamilo/farmacología , Quinasas Asociadas a rho/antagonistas & inhibidores
10.
Clin Exp Allergy ; 38(1): 135-44, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18028457

RESUMEN

BACKGROUND: Recent studies have revealed that in asthma, mast cells infiltrate to the smooth muscle layer and release tryptase, an enzymatic activator of protease-activated receptor 2 (PAR2). This phenomenon, mast cell myositis, is proposed as a new feature of asthma. However, little is known about the involvement of mast cell myositis in the pathophysiology of asthma. OBJECTIVE: This study was designed to determine whether mast cell degranulation has any functional impact on beta-adrenoceptors via PAR2 in airway smooth muscle. Moreover, we focused on Ca(2+) signalling as a mechanism underlying alteration of smooth muscle tone and responsiveness. METHODS: Isometric tension and F(340)/F(380), an indicator of the concentration of intracellular Ca(2+) ([Ca(2+)](i)), were simultaneously measured using fura-2-loaded tissues isolated from guinea-pig tracheal smooth muscle. RESULTS: Tryptase (1-100 nm) caused tension with elevated F(340)/F(380), and after exposure to tryptase for 15 min the inhibitory effect of isoprenaline (ISO) against methacholine was attenuated without elevating F(340)/F(380) in a concentration-dependent manner. Tryptase (<1 nm) had a modest effect on tension, but prolonged treatment (

Asunto(s)
Calcio/metabolismo , Mastocitos/enzimología , Músculo Liso/metabolismo , Receptores Adrenérgicos beta/metabolismo , Tráquea/metabolismo , Triptasas/metabolismo , Agonistas Adrenérgicos beta/farmacología , Animales , Señalización del Calcio/efectos de los fármacos , Cobayas , Humanos , Masculino , Mastocitos/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Receptor PAR-2/metabolismo , Tráquea/efectos de los fármacos , Quinasas Asociadas a rho/metabolismo
11.
Artículo en Inglés | MEDLINE | ID: mdl-18564632

RESUMEN

BACKGROUND: Transforming growth factor (TGF) beta1 is considered to play central roles in the pathogenesis of airway remodeling in asthma. This notion is based primarily on the results of experimental studies; clinical evidence is limited. OBJECTIVES: To ascertain the involvement of TGF-beta1 in asthma. METHODS: We studied 27 patients with moderate-to-severe, but stable, asthma treated with inhaled corticosteroids and 8 healthy controls. Helical computed tomography scans were acquired at full inspiration. Airway wall thickness (WT) was assessed on the basis of wall area corrected for body surface area (WA/BSA) and absolute WT corrected for BSA (WT/square root of BSA) according to a validated method. Induced sputum concentrations of TGF-beta1 were measured by enzyme-linked immunosorbent assay. Pulmonary function was evaluated. RESULTS: Indices of expiratory airflow were significantly lower in the asthmatic patients than in the controls. WA/BSA, WT/square root of square root of BSA, and sputum concentrations of TGF-beta1 were significantly higher in the asthmatic patients. Sputum TGF-beta1 concentrations correlated positively with WA/BSA and WT/square root of BSA and negatively with forced expiratory volume in 1 second in both asthmatic and control subjects. CONCLUSIONS: Levels of TGF-beta1 in induced sputum are elevated in asthmatic patients despite treatment with inhaled corticosteroids and are associated with airflow obstruction and airway wall thickening. TGF-beta1 is involved in the pathogenesis of airway remodeling and resultant functional impairment and it may be a target for specific medical treatment.


Asunto(s)
Corticoesteroides/uso terapéutico , Asma/metabolismo , Esputo/química , Factor de Crecimiento Transformador beta1/análisis , Adulto , Anciano , Antiasmáticos/uso terapéutico , Asma/diagnóstico por imagen , Asma/tratamiento farmacológico , Asma/patología , Femenino , Volumen Espiratorio Forzado , Humanos , Pulmón/diagnóstico por imagen , Pulmón/patología , Masculino , Persona de Mediana Edad , Tomografía Computarizada Espiral
12.
Biochim Biophys Acta ; 1036(1): 1-5, 1990 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-2223820

RESUMEN

An intracellular cyclodextrin-hydrolyzing enzyme from Bacillus sphaericus E-244 isolated from soil was purified to a homogeneous state by means of Triton X-100 extraction, DEAE-Sepharose column chromatography, hydrophobic and molecular-sieve HPLC. The enzyme was estimated to have an Mr of 72,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and 144,000 by HPLC gel filtration on TSK gel G 3000 SW. It had a pH optimum of 8.0, and the enzyme, stable at 25 degrees C and pH 5.5-9.5 for 24 h, was inactivated at 50 degrees C for 10 min. The enzyme hydrolyzed beta-cyclodextrin more effectively than linear maltooligosaccharides such as maltopentaose, maltohexaose and maltoheptaose or polysaccharides such as starch, amylopectin, amylose and pullulan.


Asunto(s)
Bacillus/enzimología , Ciclodextrinas/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Peso Molecular , Especificidad por Sustrato
13.
Clin Cancer Res ; 7(10): 3056-64, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11595695

RESUMEN

PURPOSE: A Phase I study of exatecan, a new water-soluble camptothecin derivative, was conducted to determine the maximum tolerated dose and a recommended dose, according to an internationally standardized core protocol. Pharmacological profiles of lactone and total (lactone + carboxylate) exatecan were also investigated. PATIENTS AND METHODS: Fifteen patients with advanced solid malignancies were treated with 3, 5, and 6.65 mg/m(2) of exatecan infused over 30 min every 3 weeks. Concentrations of lactone, total drug, and a metabolite in plasma and urine were determined during the first course. RESULTS: Dose-limiting neutropenia and liver dysfunction were observed in two of six patients at 6.65 mg/m(2), but no grade 3 or worse diarrhea was observed. Emesis was moderate, and no grade 3 or worse nausea and vomiting were observed at a recommended dose of 5 mg/m(2), with prophylactic use of granisetron. Pharmacokinetics were linear and had moderate variability; clearances of lactone and total drug were 6.8 +/- 2.8 and 2.1 +/- 1.1 (mean +/- SD) l/h/m(2), respectively. The ratio of lactone concentration to total drug concentration in plasma decreased from 0.81 +/- 0.06 at the end of infusion to 0.15 +/- 0.06 10 h after the infusion. The lactone:total ratio of drug exposure was 0.30 +/- 0.08, ranging from 0.16 to 0.43. Neutropenia was related to the drug exposure of both lactone and total drug. CONCLUSIONS: The recommended dose of exatecan infused over 30 min every 3 weeks is 5 mg/m(2), with a favorable toxicity profile of mild and infrequent diarrhea. Interpatient variability of pharmacokinetics was similar to or smaller than that with other camptothecin derivatives.


Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Camptotecina/uso terapéutico , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Anemia/inducido químicamente , Antineoplásicos Fitogénicos/efectos adversos , Antineoplásicos Fitogénicos/farmacocinética , Área Bajo la Curva , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Diarrea/inducido químicamente , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Neutropenia/inducido químicamente , Trombocitopenia/inducido químicamente , Factores de Tiempo , Resultado del Tratamiento , Vómitos/inducido químicamente
14.
Gene ; 207(2): 119-26, 1998 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-9511752

RESUMEN

A novel transformation technique, resident plasmid integration, for the cloning of foreign DNA in oral streptococci was described recently (T. Shiroza and H.K. Kuramitsu, Plasmid 34 (1995) 85-95. This technique is based on the integration of linearized foreign genes by recombination-proficient bacteria onto a resident plasmid, if an appropriate selection marker is flanked by the same anchor sites present in the resident plasmid. Since the transforming vehicles for this system included a pUC-derived replication origin, the high level expression in Escherichia coli cells hindered the cloning of certain genes. In the present study, new plasmids were constructed, two resident plasmids, four integration plasmids, and four cloning plasmids, all of which possess the medium-copy number replication origin, p15A ori, isolated from pACYC177. The resident plasmids consisted of the following three components: the p15A ori (0.65-kb Bg/II fragment), the pVA380-1 basic replicon functional in mutans streptococci (2.5-kb BamHI fragment), and either an erythromycin resistance or a spectinomycin resistance gene (0.9- or 1.1-kb BamHI fragment, respectively). Most of the basic replicon of pVA380-1, except for the 3'-portion of the 0.2-kb region, in the resident plasmid was replaced with a kanamycin resistance gene to construct the four integration plasmids. Therefore, the upstream and downstream anchor sites for the double cross-over event in this new system were 0.65-kb p15A ori and the 0.2-kb portion of the 3'-end of pVA380-1 replicon, respectively. This system was used to clone the gene coding for cycloisomaltooligosaccharide glucanotransferase which produces cycloisomaltooligosaccharide, a potent inhibitor of oral streptococcal glucosyltransferase, isolated from Bacillus circulans chromosome, into Streptococcus gordonii, and its gene product was successfully secreted into the culture media. Plasmids described here should be useful tools for introducing heterologous DNA into resident plasmids following integration in oral streptococci.


Asunto(s)
Bacillus/enzimología , Clonación de Organismos/métodos , Glucosiltransferasas/genética , Plásmidos , Streptococcus/genética , Bacillus/genética , Activación Enzimática , Estudios de Evaluación como Asunto , Glucosiltransferasas/metabolismo , Recombinación Genética
15.
FEBS Lett ; 290(1-2): 13-6, 1991 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-1915863

RESUMEN

The action of a cyclodextrin-hydrolyzing enzyme from Bacillus sphaericus E-244 on branched alpha- and beta-cyclodextrins was investigated. Glucosyl-alpha-cyclodextrin (6-O-alpha-D-glucosylcyclomaltohexaose) and maltosyl-alpha-cyclodextrin (6-O-alpha-D-maltosylcyclomaltohexaose) were hydrolyzed to 6(3)-O-alpha-D-glucosylmaltohexaose and 6(3)-O-alpha-D-maltosylmaltohexaose, respectively. Glucosyl-beta-cyclodextrin (6-O-alpha-D-glucosylcyclomaltoheptose) and maltosyl-beta-cyclodextrin (6-O-alpha-D-maltosyclomaltohepatose) were also mainly transformed to 6(4)-O-alpha-D-glucosylmaltoheptaose and 6(4)-O-alpha-D-maltosylmaltoheptaose, respectively. These results suggest that the cyclodextrin-hydrolyzing enzyme cleaves branched alpha- and beta-cyclodextrins at an alpha-1,4 linkage which is located furthest from the branching point on the cyclodextrin ring.


Asunto(s)
Ciclodextrinas/química , Glucano 1,4-alfa-Glucosidasa/metabolismo , Bacillus/enzimología , Ciclodextrinas/metabolismo , Hidrólisis , Cinética , Especificidad por Sustrato
16.
FEBS Lett ; 345(2-3): 135-8, 1994 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-7515357

RESUMEN

A novel enzyme, cycloisomaltooligosaccharide glucanotransferase (CITase), catalyzes the conversion of dextran to cyclic isomaltooligosaccharides by intramolecular transglucosylation (cyclization reaction). CITase was purified to homogeneity from the culture filtrate of Bacillus sp. T-3040 isolated from soil. The Mr of the enzyme was estimated to be 98,000 by SDS-PAGE. The enzyme catalyzed the cyclization reaction and gave three cyclic isomaltooligosaccharides (cycloisomalto-heptaose, -octase, and -nonaose) at a total yield of about 20%. Coupling and disproportionation reactions were also observed. These results showed that this enzyme is a multi-functional enzyme which catalyzes intramolecular and intermolecular transglucosylation.


Asunto(s)
Bacillus/enzimología , Dextranos/metabolismo , Glucosiltransferasas/aislamiento & purificación , Glucosiltransferasas/metabolismo , Oligosacáridos/metabolismo , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Cinética , Peso Molecular , Especificidad por Sustrato
17.
FEBS Lett ; 478(1-2): 34-8, 2000 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-10922465

RESUMEN

To isolate the apoptosis-linked genes involved in the cell death of thymocytes induced by glucocorticoids, we developed a functional cloning assay. Murine CD4(+)CD8(+) thymic cell line 2-257-20 cells were transfected with cDNA expression libraries obtained from a dexamethasone-resistant cell line. The transfected cells were selected in the presence of dexamethasone, and the plasmids which episomally expanded were then extracted from the surviving cells. One of the rescued cDNAs was found to be an antisense cDNA fragment identical to the mouse mitochondrial ATPase 6 gene. In the stable transfectants with the ATPase 6 antisense gene, the induction of apoptosis by dexamethasone was significantly delayed. Furthermore, the ATP synthesis in these transfectants was also reduced to some extent. ATPase 6 is a subunit of F(o)F(1) ATPase and our results support that ATP synthesis from the mitochondria is necessary for the induction of apoptosis induced by glucocorticoids.


Asunto(s)
Adenosina Trifosfatasas/genética , Apoptosis , Dexametasona/antagonistas & inhibidores , Mitocondrias/enzimología , ARN sin Sentido/metabolismo , Timo/citología , Adenosina Trifosfatasas/metabolismo , Adenosina Trifosfato/antagonistas & inhibidores , Adenosina Trifosfato/metabolismo , Animales , Apoptosis/efectos de los fármacos , Muerte Celular , Clonación Molecular , Dexametasona/farmacología , Citometría de Flujo , Genes Dominantes/genética , Ratones , Ratones Endogámicos BALB C , ATPasas de Translocación de Protón Mitocondriales , Datos de Secuencia Molecular , Mutación/genética , ARN sin Sentido/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Timo/efectos de los fármacos , Timo/enzimología , Timo/metabolismo , Transfección , Células Tumorales Cultivadas
18.
Clin Pharmacokinet ; 11(2): 154-63, 1986.
Artículo en Inglés | MEDLINE | ID: mdl-3956048

RESUMEN

A novel pharmacokinetic method was developed for analysing the behaviour of a drug in tissues. The absolute transfer ratio of a drug to a tissue was defined using the pharmacokinetic parameters obtained by this method. Composite data of latamoxef (moxalactam) concentration in maternal blood, umbilical cord blood and amniotic fluid following a 2g intravenous injection to pregnant women at delivery were analysed by this method to study the drug behaviour in pregnant women, fetuses and amniotic fluid. Latamoxef kinetics in pregnant women at full term were generally similar to that in previously reported healthy subjects. The concentration of latamoxef in umbilical cord blood peaked about 2 hours after dosing then decreased in parallel with the maternal blood concentration. The amniotic fluid concentration peaked about 7 hours after administration, then decreased slowly. The absolute transfer ratios to fetus and amniotic fluid were calculated to be about 2.5 and 0.37% respectively.


Asunto(s)
Intercambio Materno-Fetal , Moxalactam/metabolismo , Líquido Amniótico/metabolismo , Femenino , Sangre Fetal/metabolismo , Humanos , Inyecciones Intravenosas , Cinética , Matemática , Modelos Biológicos , Moxalactam/sangre , Embarazo , Distribución Tisular
19.
Biochem Pharmacol ; 53(12): 1779-87, 1997 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-9256152

RESUMEN

We previously reported that, in isolated perfused rat livers in a constant flow system, oxethazaine (OXZ) rapidly increased portal pressure (PP) accompanied by inhibition of oxygen uptake and the subsequent metabolic effects. In this study, hemodynamic changes were studied by using an indicator dilution technique and by microscopic observation of post-fixed liver samples stained with acridine orange or trapped fluorescence microspheres (FMSs). During the increase in PP induced by OXZ, the mean transit times of both red blood cells and azoalbumin were shortened markedly, and the vascular and extravascular albumin spaces decreased to 55 and 18% of the controls, respectively. With acridine orange, in the control livers, all the dye infused was taken up and the periportal zones were uniformly stained over all the liver sections, whereas in the OXZ-treated livers, about 30% of the dye drained out, and extensive staining was observed in the central portion of the liver mass, but the peripheral portions of the liver were much less stained. The staining was often localized around large portal vein branches and spread toward the hepatic veins. These changes were recoverable in the absence of OXZ. Distributions of 1-microm and 15-microm FMSs were likewise altered by OXZ. Thus, uneven perfusion may be the primary cause of decreased tissue spaces and also of the metabolic effects produced by OXZ. Endothelin 1 also produced OXZ-like changes, while U-46619 had lesser effects. The methodology used in this study may help delineate the hepatic perfusion disturbance caused by various vasoconstrictors.


Asunto(s)
Etanolaminas/farmacología , Circulación Hepática/efectos de los fármacos , Hígado/efectos de los fármacos , Microcirculación/efectos de los fármacos , Vasoconstrictores/farmacología , Naranja de Acridina , Animales , Presión Sanguínea/efectos de los fármacos , Colorantes , Fluorescencia , Hígado/irrigación sanguínea , Hígado/ultraestructura , Masculino , Perfusión , Ratas , Ratas Sprague-Dawley
20.
Int J Parasitol ; 23(6): 757-63, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8300285

RESUMEN

Inflammatory reactions to the lung fluke, Paragonimus westermani, in an abnormal host, the rat, were studied by electron microscopy. Inflammatory cells accumulated around the worms in rat muscles, but the reaction varied significantly in intensity as well as distribution of inflammatory cells from worm to worm in the same and different hosts. In an accumulation of inflammatory infiltrates around the worm, eosinophils were more commonly seen, and neutrophils and macrophages were fewer in number. Mast cells appeared rarely. Where inflammatory cells touched to the worms, the tegument of the worms was covered with moderately electron-dense flocculent material which included dense granules. This material, which probably consisted of immune complexes of host antibody and antigen secreted from tegumental granules, seemed to block the inflammatory cells from adhering to the worm surfaces. Inflammatory cells made direct contact with worm surfaces where flocculent material was absent. Dense secretory material was discharged from some eosinophils as a result of degranulation.


Asunto(s)
Paragonimiasis/veterinaria , Ratas Sprague-Dawley/parasitología , Enfermedades de los Roedores/patología , Animales , Braquiuros/parasitología , Inflamación/patología , Inflamación/veterinaria , Músculos/parasitología , Músculos/ultraestructura , Paragonimiasis/patología , Paragonimus/fisiología , Ratas , Especificidad de la Especie
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