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1.
Fujita Med J ; 8(1): 17-24, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35233343

RESUMEN

OBJECTIVE: The prevalence of obstructive sleep apnea (OSA) in Japan is 9% among males and 3% among females. Up to 2.5 million patients are estimated to suffer from the disease, but limited number of facilities are capable of carrying out polysomnography (PSG), leaving more than 80% of these individuals are undiagnosed. In recent years, the development of new portable sleep monitoring (PMs) devices has been remarkable. We evaluate the correlation between the results of the LS-140 PMs device (Fukuda Denshi Tech Co. Ltd.), released in 2017, and those of PSG. METHODS: We obtained contemporaneous data from the same patients by equipping 58 patients with PMs (LS-140) devices while they underwent PSG. Our primary outcome was Case 2 of the intraclass correlation coefficient (ICC), i.e., the ICC (2.1). And we used a Bland-Altman analysis to compare the apnea-hypopnea index (AHI) given by PSG and the respiratory event index (REI) given by LS-140 and examined the sensitivity and specificity of the REI relative to the AHI in the diagnosis of OSA. We also carried out the same comparison but in terms of the presence or absence of periodic limb movements (PLMs). RESULTS: The ICC (2.1) between The REI and the AHI was 0.944, a rather high value (p<0.0001). The mean difference between AHI and REI values was -3.6 (p<0.0001), indicating a negative fixed bias. Sensitivity may decrease in groups with PLMs. CONCLUSION: The REI and the AHI are highly correlated, giving LS-140 sufficient diagnostic sensitivity and specificity to screen for OSA.

2.
Respir Med Case Rep ; 34: 101492, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34401316

RESUMEN

A 34-year-old woman visited our hospital because she had had abdominal bloating for 2 months. She had been diagnosed with invasive thymoma (WHO pathological type B2), for which she had undergone chemotherapy and total thymectomy 10 years previously. Six years previously, pleural dissemination was diagnosed and she had undergone right extra-pleural pneumonectomy. On presentation to our hospital, abdominal computed tomography and ultrasound scans revealed abundant ascites and a huge liver lesion, likely a metastasis from her thymoma, obstructing the inferior vena cava. The serum-ascites albumin gradient was high at 1.4 g/dL, which indicated portal hypertension. We diagnosed Budd-Chiari syndrome caused by liver metastasis from a previous thymoma. Steroid therapy resulted in shrinkage of her liver tumor and a marked decrease in her ascites. Although rare, Budd-Chiari syndrome caused by liver metastasis from a thymoma is a possible serious complication of advanced invasive thymoma.

3.
PLoS One ; 13(11): e0206972, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30452447

RESUMEN

Lymphocyte profiles in mediastinal lymph nodes may reflect the immune status of patients with sarcoidosis. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is useful for the diagnosis of diseases with mediastinal lymphadenopathy including sarcoidosis. The purpose of this study was to determine lymphocyte profiles of lymph nodes in sarcoidosis by analyzing EBUS-TBNA samples. We prepared single cell suspensions from EBUS-TBNA samples of mediastinal lymph nodes from patients with sarcoidosis or lung cancer and analyzed surface markers (CD3, CD4, CD8, CD19, CD25) and FoxP3 expression in the resultant lymphocytes using flow cytometry. We studied 26 patients with sarcoidosis and 16 with lung cancer with mediastinal lymph node metastases. In sarcoidosis, the CD4/CD8 ratio was significantly more elevated in lymph nodes than in bronchoalveolar lavage fluid (P<0.001), although both were strongly correlated. The CD4/CD8 ratio was significantly higher in stage I than in stage II both in the BAL fluid and lymph nodes. When compared with lung cancer lymph node metastasis, the CD4/CD8 ratio was significantly higher in sarcoidosis, whereas the CD3/CD19 ratio was significantly higher in lung cancer. The proportion of regulatory T cells (CD4+, CD25+, FoxP3 high) did not differ between sarcoidosis and lung cancer samples. Lymphocyte profiles in mediastinal lymphadenopathy can be analyzed by flow cytometry of EBUS-TBNA samples. These findings might help elucidate the immunopathology of sarcoidosis.


Asunto(s)
Citometría de Flujo , Linfadenopatía/metabolismo , Linfocitos/metabolismo , Enfermedades del Mediastino/metabolismo , Sarcoidosis/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Biopsia , Relación CD4-CD8 , Femenino , Citometría de Flujo/métodos , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Linfadenopatía/diagnóstico , Masculino , Enfermedades del Mediastino/diagnóstico , Persona de Mediana Edad , Sarcoidosis/diagnóstico , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Adulto Joven
4.
Intern Med ; 57(15): 2157-2163, 2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-29607972

RESUMEN

Objective Sleep apnea syndrome is more prevalent among men than women and is frequently accompanied by metabolic syndrome (MetS). However, gender differences in the effect of sleep-disordered breathing (SDB) leading to the risk of MetS remain unclear. The aim of our study was to investigate the clinical characteristics of SDB in women and the differential influence of SDB on MetS between genders. Methods In a single-center retrospective study, we compared the data of 1,809 consecutive SDB patients by gender to clarify the characteristics of sleep disorders in women. We also compared the prevalence of MetS and its related abnormalities by gender. A logistic regression analysis was used to determine the contributory factors for MetS. Results The mean age and proportion of patients over 50 years of age were higher in women than in men. SDB was milder in women than in men according to polysomnography findings. Elevated Hemoglobin A1c levels and hyperlipidemia were less frequent in women than in men. The MetS prevalence was similar in women and men (30.0% vs. 35.2%). A logistic regression analysis showed that the apnea-hypopnea index (AHI) was an independent risk factor for MetS in both genders, but that female gender was independently associated with a decreased prevalence of MetS and its related abnormalities. Conclusion Female SDB patients tend to be older with milder apnea and sleepiness than male SDB patients. A higher AHI is a significant risk factor for MetS in both genders, although female gender is an independent inhibitory factor for developing MetS in SDB patients.


Asunto(s)
Síndrome Metabólico/epidemiología , Síndromes de la Apnea del Sueño/epidemiología , Síndromes de la Apnea del Sueño/fisiopatología , Factores de Edad , Anciano , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Polisomnografía , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales
5.
BMC Pulm Med ; 17(1): 175, 2017 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-29212495

RESUMEN

BACKGROUND: When epidermal growth factor receptor (EGFR) gene mutation-positive non-small cell lung cancer (NSCLC) acquires resistance to the initial tyrosine kinase inhibitor (TKI) treatment, reassessing the tumor DNA by re-biopsy is essential for further treatment selection. However, the process of TKI-sensitive tumor re-progression and whether re-biopsy is possible in all cases of acquired resistance to EGFR-TKI remain unclear. METHODS: We retrospectively analyzed data from 69 consecutive patients with EGFR gene mutation-positive advanced NSCLC who had been treated with EGFR-TKI and exhibited disease relapse after initial disease remission. The relapsing lesions were identified at the time of RECIST-progressive disease (PD) and clinical-PD (when the attending physician judged the patient as clinically relapsing and stopped EGFR-TKI therapy). We determined the potential re-biopsy methods for each relapsing lesion and evaluated their feasibility according to difficulty and invasiveness criteria as follows: category A, accessible by conventional biopsy techniques; category B, difficult (but possible) to biopsy and accessible with invasive methods; and category C, extremely difficult to biopsy or inaccessible without using highly invasive methods, including surgical biopsy. RESULTS: The total feasibility rate of re-biopsy (category A or B) was 68% at RECIST-PD and 84% at clinical-PD, and the most common accessible relapsing lesions were primary tumors at RECIST-PD and pleural effusion at clinical-PD. All relapsing lesions at primary sites (categories A and B) were assessed as having the potential for re-biopsy. However, re-biopsy for metastasis was assessed as difficult in a substantial proportion of the study population (42 and 20% category C at RECIST-PD and clinical-PD, respectively). CONCLUSIONS: Re-biopsy of relapsing disease is feasible in many cases, although it may present difficulties in cases with, e.g., metastatic relapsing lesions. To facilitate treatment strategies in NSCLC patients with relapse after EGFR-TKI therapy, re-biopsy should be standardized with the use of simpler and more reliable methods.


Asunto(s)
Adenocarcinoma/genética , Biopsia/métodos , Carcinoma de Pulmón de Células no Pequeñas/genética , Resistencia a Antineoplásicos , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Recurrencia Local de Neoplasia/genética , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia con Aguja , Broncoscopía , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Estudios de Cohortes , Progresión de la Enfermedad , Receptores ErbB/antagonistas & inhibidores , Estudios de Factibilidad , Femenino , Humanos , Biopsia Guiada por Imagen , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Inhibidores de Proteínas Quinasas/uso terapéutico , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
6.
Support Care Cancer ; 25(4): 1215-1220, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27966021

RESUMEN

PURPOSE: The purpose of this study was to evaluate renal function in lung cancer patients who were administered cisplatin with continuous higher-volume hydration (CH) or a short hydration (SH) regimen. METHODS: We retrospectively evaluated patients with lung cancer who were treated with chemotherapy regimens including >50 mg/m2 of cisplatin between August 2007 and March 2015. Between August 2007 and December 2012, patients received a continuous higher-volume hydration regimen without magnesium (Mg) supplementation (CH group), and after May 2013, patients received a short hydration regimen with Mg supplementation (SH group). To evaluate the factors influencing serum creatinine (SCr) increase during the first course of cisplatin chemotherapy, univariate and multivariate logistic regression analyses were conducted. RESULTS: A total of 122 patients were evaluated, 62 patients in the CH group and 60 patients in the SH group. Grade 1 (National Cancer Institute Common Toxicity Criteria for Adverse Events; version 4.0) or higher SCr increases were more frequently observed in the CH group than in the SH group after the first cycle (P = 0.01, Fisher's exact test) and for all cycles (P = 0.03). Multivariate analysis revealed that short hydration (odds ratio (OR), 0.30; 95% confidence internal (CI) (0.11-0.75), P = 0.01) and estimated creatinine clearance (eCcr) of ≥70 mL/min (OR, 0.25; 95% CI (0.088-0.69), P = 0.008) were associated with a significantly reduced risk for cisplatin-induced grade 1 or higher SCr increase. CONCLUSION: Our study suggested that a short hydration method with Mg supplementation and eCcr of ≥70 mL/min reduced the risk of cisplatin-induced nephrotoxicity.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Cisplatino/toxicidad , Riñón/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Magnesio/uso terapéutico , Adulto , Anciano , Femenino , Humanos , Riñón/metabolismo , Riñón/patología , Neoplasias Pulmonares/complicaciones , Magnesio/administración & dosificación , Magnesio/farmacología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
8.
Ther Adv Respir Dis ; 10(6): 518-524, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27595645

RESUMEN

BACKGROUND: Bronchial occlusion with an Endobronchial Watanabe Spigot (EWS) has been shown to be useful in managing prolonged bronchopleural fistulas and intractable hemoptysis. EWS bronchial occlusion using a curette is less technically demanding. This retrospective study evaluated the clinical utility and simplicity of this method. METHODS: A total of 18 consecutive patients (15 men, 3 women, aged 47-85 years) who underwent bronchial occlusion using an EWS from April 2012 to August 2014 were evaluated. The method involves sticking the tip of a curette into an EWS to the first joint, allowing it to be turned in any direction or at any angle. The time required to occlude the target bronchus was measured on routinely recorded digital videos. Other parameters evaluated included success rates, complications, and clinical outcomes. RESULTS: Of the 18 patients, 11 underwent bronchial occlusion for intractable pneumothorax, 5 for postoperative bronchopleural fistula, two for intractable empyema, and one for hemoptysis. Each patient required 1-7 EWSs (median 4). Target bronchi included the right upper (n = 8), left upper (n = 5), right lower (n = 2), left lower (n = 2), and right middle (n = 1) bronchi. The success rate of EWS insertion into the target bronchus was 100%. Time per EWS occlusion ranged from 65-528 sec (median 158.5 sec). Of the 62 insertions, 36 (58.1%) were completed within 3 min, and 58 (93.5%) within 5 min. Successful outcomes were observed in 15 (83.3%) of the 18 patients. CONCLUSIONS: EWS bronchial occlusion using a curette is a simple method for managing intractable bronchopleural fistulas in daily clinical settings.


Asunto(s)
Fístula Bronquial/terapia , Enfermedades Pleurales/terapia , Neumotórax/terapia , Oclusión Terapéutica/métodos , Anciano , Anciano de 80 o más Años , Empiema/terapia , Femenino , Hemoptisis/terapia , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Elastómeros de Silicona , Oclusión Terapéutica/instrumentación , Factores de Tiempo , Resultado del Tratamiento
9.
BMC Med Imaging ; 15: 21, 2015 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-26092497

RESUMEN

BACKGROUND: Recent advances in bronchoscopy, such as transbronchial biopsy (TBB) using endobronchial ultrasonography with a guide sheath (EBUS-GS), have improved the diagnostic yield of small-sized peripheral lung lesions. In some cases, however, it is difficult to obtain adequate biopsy samples for pathological diagnosis. Adequate prediction of the diagnostic accuracy of TBB with EBUS-GS is important before deciding whether bronchoscopy should be performed. METHODS: We retrospectively reviewed 149 consecutive patients who underwent TBB with EBUS-GS for small-sized peripheral lung lesions (≤30 mm in diameter) from April 2012 to March 2013. We conducted an exploratory analysis to identify clinical factors that can predict an accurate diagnosis by TBB with EBUS-GS. All patients underwent thin-section chest computed tomography (CT) scans (0.5-mm slices), and the CT bronchus sign was evaluated before bronchoscopy in a group discussion. The final diagnoses were pathologically or clinically confirmed in all studied patients (malignant lesions, 110 patients; benign lesions, 39 patients). RESULTS: The total diagnostic yield in this study was 72.5% (95% confidence interval: 64.8-79.0%). Lesion size, lesion visibility on chest X-ray, and classification of the CT bronchus sign were factors significantly associated with the definitive biopsy result in the univariate analysis. In the multivariate analysis, only the CT bronchus sign remained as a significant predictive factor for successful bronchoscopic diagnosis. The CT bronchus sign was also significantly associated with the EBUS findings of the lesions. CONCLUSION: Our results suggest that the CT bronchus sign is a powerful predictive factor for successful TBB with EBUS-GS.


Asunto(s)
Broncografía/métodos , Broncoscopía/métodos , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/métodos , Endosonografía/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/instrumentación , Endosonografía/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de Riesgo , Sensibilidad y Especificidad
10.
Case Rep Oncol ; 8(1): 78-82, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25848356

RESUMEN

A 72-year-old man undergoing continuous ambulatory peritoneal dialysis (CAPD) for chronic renal failure and who had undergone right upper lobectomy for lung adenocarcinoma (pT2aN0M0) 2 years ago was admitted for recurrence of lung cancer presenting as multiple brain metastases. An epidermal growth factor receptor mutation analysis of his lung cancer revealed a deletion of 15 nucleotides (E746-A750) in exon 19. After whole-brain radiotherapy, we started daily administration of 250 mg gefitinib under the continuation of CAPD and performed a pharmacokinetic analysis. We speculated that the plasma concentration of gefitinib reached the steady state at least by day 16 after the start of gefitinib (626.6 ng/ml at trough level). On day 46, the plasma concentration was 538.4 ng/ml at trough level and the concentration in the peritoneal dialysis fluid was 34.6 ng/ml, suggesting that CAPD appeared to have little effect on the pharmacokinetics of gefitinib. During gefitinib therapy, there were no significant adverse events except for grade 2 diarrhea. Gefitinib could be safely administered to a patient undergoing CAPD.

11.
Gan To Kagaku Ryoho ; 42(2): 183-7, 2015 Feb.
Artículo en Japonés | MEDLINE | ID: mdl-25743136

RESUMEN

BACKGROUND: Cisplatin plus pemetrexed is considered the standard of care for the first-line treatment of patients with advanced non-squamous non-small-cell lung cancer (NSCLC). However, little is known about the efficacy and safety of this regimen in Japanese patients in a daily clinical setting. METHODS: We retrospectively analyzed 40 patients who received cisplatin (75 mg/m/(2)) and pemetrexed (500 mg/m(2)) as a first-line treatment for advanced non-squamous NSCLC. RESULTS: Recorded Grade 3 or 4 hematological toxicities included neutropenia in 7 cases (17.5%), leukopenia in 5 cases (12.5%), anemia in 1 case (2.5%), thrombocytopenia in 1 case (2.5%), and febrile neutropenia in 1 case (2.5%). Grade 3 or 4 nonhematological toxicities included anorexia in 3 cases (7.5%), infection in 1 case (2.5%), rash in 1 case (2.5%), and increased transaminase expression in 1 case (2.5%). Therefore, the adverse events were mostly mild. There were no treatment related deaths. The overall response rate was 37.5%, median progression free survival was 5.6 months, and median overall survival (OS) was 18.8 months. In an epidermal growth factor receptor (EGFR) mutation status subgroup analysis, the median OS of patients with wild-type EGFR or unknown status (n=28)was 16.8 months. CONCLUSION: Cisplatin plus pemetrexed was well tolerated as a first-line treatment and effective in Japanese patients with advanced non-squamous NSCLC.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Pueblo Asiatico , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Femenino , Glutamatos/administración & dosificación , Glutamatos/efectos adversos , Guanina/administración & dosificación , Guanina/efectos adversos , Guanina/análogos & derivados , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pemetrexed , Estudios Retrospectivos , Resultado del Tratamiento
12.
Respir Investig ; 52(3): 153-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24853014

RESUMEN

BACKGROUND: Newer more advanced techniques in bronchoscopy may require longer procedure times, although a standard protocol for sedation during prolonged bronchoscopy has not yet been defined. METHODS: We designed a prospective, non-randomized, single-arm study (UMIN trial number 000003971) using patient questionnaires and vital sign monitoring to assess the efficacy and safety of a standardized midazolam dosing protocol based on gender and age for use during bronchoscopy. The loading dose of midazolam was 0.075mg/kg for men ≤65 years old and women ≤70 and 0.05mg/kg for men ≥66 years and women ≥71 years, with subsequent doses of one-half the loading dose to be administered every 20min. The primary endpoint was tolerability and secondary endpoints included anxiety and recall of procedure, willingness to undergo repeat procedure, and complications. Safety was evaluated in terms of monitored changes in blood pressures, ECG, oxygen saturation, and CO2 content in expiration during the procedure. RESULTS: A total of 204 patients were included in the study. Overall, 163 patients (79.9%) reported "no distress" during the procedure, 185 patients (90.7%) reported "no anxiety," and 175 (85.8%) replied that they would accept a repeat procedure, if necessary. The mean minimum oxygen saturation was 90.2% and the mean maximum expiratory CO2 level was 37.7mmHg. There were no serious complications related to the protocol. CONCLUSIONS: The midazolam dosing protocol examined in this study was safe and effective. It is simple, and it could easily be translated to routine clinical practice.


Asunto(s)
Broncoscopía/métodos , Sedación Consciente/métodos , Hipnóticos y Sedantes/administración & dosificación , Midazolam/administración & dosificación , Medicina de Precisión/métodos , Adulto , Anciano , Determinación de Punto Final , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Tempo Operativo , Estudios Prospectivos , Encuestas y Cuestionarios , Signos Vitales , Adulto Joven
13.
Plant Cell ; 15(12): 2900-10, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14615594

RESUMEN

We characterized a rice dwarf mutant, ebisu dwarf (d2). It showed the pleiotropic abnormal phenotype similar to that of the rice brassinosteroid (BR)-insensitive mutant, d61. The dwarf phenotype of d2 was rescued by exogenous brassinolide treatment. The accumulation profile of BR intermediates in the d2 mutants confirmed that these plants are deficient in late BR biosynthesis. We cloned the D2 gene by map-based cloning. The D2 gene encoded a novel cytochrome P450 classified in CYP90D that is highly similar to the reported BR synthesis enzymes. Introduction of the wild D2 gene into d2-1 rescued the abnormal phenotype of the mutants. In feeding experiments, 3-dehydro-6-deoxoteasterone, 3-dehydroteasterone, and brassinolide effectively caused the lamina joints of the d2 plants to bend, whereas more upstream compounds did not cause bending. Based on these results, we conclude that D2/CYP90D2 catalyzes the steps from 6-deoxoteasterone to 3-dehydro-6-deoxoteasterone and from teasterone to 3-dehydroteasterone in the late BR biosynthesis pathway.


Asunto(s)
Colestanoles/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Oryza/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteínas de Plantas/genética , Esteroides Heterocíclicos/metabolismo , Secuencia de Aminoácidos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brasinoesteroides , Colestanoles/farmacología , Sistema Enzimático del Citocromo P-450/genética , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Mutación , Oryza/efectos de los fármacos , Oryza/genética , Fenotipo , Filogenia , Mapeo Físico de Cromosoma , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/metabolismo , Homología de Secuencia de Aminoácido , Esteroides Heterocíclicos/farmacología
14.
Plant J ; 32(4): 495-508, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12445121

RESUMEN

Molecular genetic and physiological studies on brassinosteroid (BR)-related mutants of dicot plants have revealed that BRs play important roles in normal plant growth and development. However, little is known about the function of BR in monocots (grasses), except for the phenotypic analysis of a rice mutant partially insensitive to BR signaling. To investigate the function of BR in monocots, we identified and characterized BR-deficient mutants of rice, BR-deficient dwarf1 (brd1). The brd1 mutants showed a range of abnormalities in organ development and growth, the most striking of which were defects in the elongation of the stem and leaves. Light microscopic observations revealed that this abnormality was primarily owing to a failure in the organization and polar elongation of the leaf and stem cells. The accumulation profile of BR compounds in the brd1 mutants suggested that these plants may be deficient in the activity of BR C-6 oxidase. Therefore, we cloned a rice gene, OsDWARF, which has a high sequence similarity to the tomato C-6 oxidase gene, DWARF. Introduction of the wild-type OsDWARF gene into brd1 rescued the abnormal phenotype of the mutants. The OsDWARF gene was expressed at a low level in all of the examined tissues, with preferential expression in the leaf sheath, and the expression was negatively regulated by brassinolide treatment. On the basis of these findings, we discuss the biological function of BRs in rice plants.


Asunto(s)
Mutación , Oryza/citología , Oryza/enzimología , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Hojas de la Planta/citología , Tallos de la Planta/citología , Alelos , Secuencia de Aminoácidos , Brasinoesteroides , Polaridad Celular , Colestanoles/farmacología , Perfilación de la Expresión Génica , Genes de Plantas/genética , Prueba de Complementación Genética , Datos de Secuencia Molecular , Oryza/genética , Oryza/crecimiento & desarrollo , Oxidorreductasas/química , Fenotipo , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Tallos de la Planta/enzimología , Tallos de la Planta/genética , Tallos de la Planta/crecimiento & desarrollo , Esteroides Heterocíclicos/farmacología
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