RESUMEN
As a toxic heavy metal, cadmium (Cd) is one of the principal pollutants influencing rice productivity and food security. Despite several studies, the underlying mechanism of Cd response in plants remains largely unclear. Dehydrins are part of the late embryogenesis abundant (LEA) family which protect plants against abiotic stresses. In this study, a Cd-responsive LEA gene, OsDHN2, was functionally characterized. The chromosome localization results indicated that OsDHN2 was located on chromosome 2 of rice. Meanwhile, cis-acting elements, such as MBS (MYB binding site involved in drought-inducibility), ARE (anaerobic induction), and ABRE (abscisic acid), were present in the OsDHN2 promoter region. Expression pattern analysis also showed that OsDHN2 expression was induced in both roots and shoots under Cd stress. Overexpression of OsDHN2 improved Cd tolerance and reduced Cd concentration in yeast. Moreover, increased expression levels of SOD1, CTA1, GSH1, or CTT1 were found in transgenic yeast under Cd stress, suggesting the increased antioxidant enzymatic activities. These results suggested that OsDHN2 is a Cd-responsive gene that has the potential to improve resistance to Cd in rice.
Asunto(s)
Cadmio , Oryza , Cadmio/toxicidad , Cadmio/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/genética , Oryza/metabolismo , Biología Computacional , Regulación de la Expresión Génica de las PlantasRESUMEN
Ecological and environmental problems including heavy metal pollution have received increasing concerns. Given the shortage of physical and chemical remediation methods in high cost and secondary pollution, using plants and microorganisms for joint remediation of environment has become one of the most important strategies. Root exudates are an important medium for information and nutrient exchange between plants and soil. The roles of plant root exudates in remediation of polluted and degradated soil have been widely studied. In this review, we described the composition, secretion mechanism and functions of root exudates and summarized the functions of root exudate in heavy metal absorption, allelopathy, interaction between roots and rhizosphere microorga-nisms, and changes in soil physical and chemical properties. The progress, challenges and prospect of applying root exdudates and rhizosphere microorganisms in the remediation of ecology and environment have also been discussed. This review could provide theoretical support for the application of plant-microorganism based environmental remediation.
Asunto(s)
Metales Pesados , Contaminantes del Suelo , Biodegradación Ambiental , Exudados y Transudados/química , Exudados de Plantas , Raíces de Plantas/química , Rizosfera , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisisRESUMEN
OBJECTIVE: To identify the clinical features of patients with giant cell tumors (GCT) of long bones in extremities presented with pathological fracture (PF), and discuss the surgical strategy with retrospective analysis and literature review. METHODS: We searched medical electronic records from January 1999 to December 2011 in our hospital to identify patients with definite diagnosis of extremity GCT presented with PF. Clinical data including gender, tumor site, age, surgical treatment option, postoperative complication, limb function, local recurrence and pulmonary metastasis were collected and analyzed statistically. The t-test and chi-square test were used for continuous and dichotomous variables, respectively. RESULTS: Between 1999 and 2011 we treated 201 patients with GCT in extremities (long bone only: femur, tibia, fibula, humerus, ulna, and radius), 33 of whom presented with a PF. The gender ratio was 1.06 for a male predominance. The median age was 33 (15-62), and the most common site of pathologic fractures was distal femur (n=17), followed by proximal tibia (n=5), proximal femur (n=5), proximal humerus (n=4), and distal radius (n=2). Nine fractures were intra-articular. The tumors were treated by extended curettage (n=11) or en bloc excision (n=22), and the fractures were reconstructed by endoprosthesis (n=20), autologous iliums graft combined with synthetic bone substitutes (n=7), acrylic cementing (n=3), autologous fibula graft (n=2), or allograft (n=1). Ten operations were followed by complications of any kind, where implant failure and recurrence were the commonest, and re-operation rate was 27.3%. The mean functional score according to the scoring system of the Musculoskeletal Tumor Society (MSTS) was 81% in patients who received endoprosthesis replacement and 82% in other reconstruction options. CONCLUSION: Extended curettage and en bloc resection were all considered to be the effective treatment options for patients with extremity GCT presented with PF. However, local recurrence and implant related complication were the major concern for joint reservation and prosthetic replacement, respectively.
Asunto(s)
Neoplasias Óseas/cirugía , Fracturas Espontáneas/cirugía , Tumor Óseo de Células Gigantes/cirugía , Adolescente , Adulto , Neoplasias Óseas/complicaciones , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/patología , Legrado , Extremidades , Femenino , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/etiología , Fracturas del Fémur/cirugía , Estudios de Seguimiento , Fracturas Espontáneas/diagnóstico por imagen , Fracturas Espontáneas/etiología , Tumor Óseo de Células Gigantes/complicaciones , Tumor Óseo de Células Gigantes/diagnóstico por imagen , Tumor Óseo de Células Gigantes/patología , Humanos , Fracturas del Húmero/diagnóstico por imagen , Fracturas del Húmero/etiología , Fracturas del Húmero/cirugía , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/etiología , Fracturas Intraarticulares/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Fracturas del Radio/diagnóstico por imagen , Fracturas del Radio/etiología , Fracturas del Radio/cirugía , Estudios Retrospectivos , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/etiología , Fracturas de la Tibia/cirugía , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: To determine the independent prognostic factors of primary synovial sarcoma. METHODS: The clinical data of 52 patients followed up from 66 patients with synovial sarcoma treated between September 1997 and September 2008 was analyzed retrospectively. There were 28 male and 24 female patients aged from 11 to 71 years old. Three and five-year overall survival (OS), recurrence rate and 9 prognostic factors were analyzed in this study. Univariate and multivariate analysis were performed to determine the prognostic factors of OS. RESULTS: Fifty-two patients were followed up with the follow-up time ranged from 6 to 88 months (median 32 months). The 3-, 5-year overall survival rate and local recurrence rate were 52.8%, 30.3% and 32.7% respectively. Univariate showed tumor size < 5 cm, tumor located at extremities, adequate surgical margin and radical resection combined with radiotherapy had better survival rate (P < 0.05). Multivariate analysis demonstrated that tumor size, primary site and adequate surgical margin were independent prognostic factors for OS. Patients received radical resection combined with radiotherapy have longer median relapse time (25 months) compared with marginal resection combined with radiotherapy (18 months) and single radical resection (12 months). Thirty-five (67%) patients were treated with chemotherapy and seventeen (33%) patients received no chemotherapy for the primary tumor. Treatment with chemotherapy was not associated with an improved OS (P = 0.52). CONCLUSIONS: The independent prognostic factors of synovial sarcoma are tumor size, primary site and adequate surgical margin. Doxorubicin and ifosfamide based chemotherapy was not associated with an improved OS in patients with synovial sarcoma. Radical resection combined with radiotherapy can best control local condition.