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2.
Eur Radiol ; 33(5): 3103-3114, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36571605

RESUMO

OBJECTIVES: The pandemic caused by SARS-CoV-2 has led to the rapid publication of numerous radiology articles, primarily focused on disease diagnosis. The objective of this study is to analyze the intellectual structure of radiology research on COVID-19 using a citation and co-citation analysis. METHODS: We identified all documents about COVID-19 published in radiology journals included in the Web of Science in the period 2020-2021, conducting a citation analysis. Then we identified all bibliographic references that were cited by these documents, generating a co-citation matrix that was used to perform a co-citation network. RESULTS: Of the 3418 documents indexed in WoS, 857 were initially "Early Access," 2223 had citations, 393 had more than 20 citations, and 83 had more than 100 citations. The USA had the highest number of publications (32.62%) and China had the highest rate of funded studies (45.38%). The three authors with the most publications were affiliated with Italian institutions, while the five most cited authors were Chinese. A total of 647 publications were co-cited at least 12 times and were published in 206 different journals, with 49% of the documents found in radiology journals. The institutions with the greatest presence among these co-cited articles were Chinese and American. CONCLUSION: This co-citation analysis is the first to focus exclusively on radiology articles on COVID-19. Our study confirms the existence of interrelated thematic clusters with different specific weights. KEY POINTS: • As the pandemic caused by SARS-Cov-2 has led to the rapid publication of numerous radiology studies in a short time period, a bibliometric review based on citation and co-citation analysis has been conducted. • The co-citation analysis supported the identification of key themes in the study of COVID-19 in radiology publications. • Many of the most co-cited articles belong to a heterogeneous group of publications, with authors from countries that are far apart and even from different disciplines.


Assuntos
COVID-19 , Publicações Periódicas como Assunto , Radiologia , Humanos , Estados Unidos , SARS-CoV-2 , Bibliometria
3.
BMJ Case Rep ; 14(11)2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34753729

RESUMO

Primary neuroendocrine tumours of the kidney are rare, and their pathophysiology is uncertain; since their discovery in 1966, they have been described only a few times in the literature. We present a case of a well-differentiated neuroendocrine tumour of the kidney in an asymptomatic patient, which required a multidisciplinary approach by the hospital's team, including precise surgical treatment and an effective radiopathological diagnosis. The patient underwent right radical nephrectomy. During follow-up, he remained asymptomatic, and no metastases or complications were identified.


Assuntos
Neoplasias Renais , Tumores Neuroendócrinos , Humanos , Rim/diagnóstico por imagem , Rim/cirurgia , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/cirurgia , Masculino , Nefrectomia , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/cirurgia
4.
Cureus ; 13(7): e16295, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34381653

RESUMO

Posterior reversible encephalopathy syndrome is an increasingly recognized disorder characterized by a headache, visual disturbances, and seizures. It is a reversible neurotoxic state, with multiple risk factors in which endothelial injury and compromised brain perfusion are the common characteristics. Diagnosis is usually made by cerebral magnetic resonance imaging that typically shows early-stage bilateral symmetrical parieto-occipital hyperintensities on T2 and fluid-attenuated inversion recovery (FLAIR) sequences. However, other locations have been described where the disease may appear less frequently. We describe the case of a 62-year-old man, with a medical history of hypertension, who presented with anisocoria with mydriatic non-reactive pupil and ptosis of the left eye. CT head showed a slightly hypodense brainstem, in relation to vasogenic edema. This was confirmed with magnetic resonance imaging. The angiography did not identify cerebral artery aneurysms. The symptoms and radiological findings were almost completely reversible after improving the patient's blood pressure. This case highlights a rare single presentation of posterior reversible encephalopathy syndrome associated with subarachnoid hemorrhage. A high index of suspicion, careful examination, and exploration with imaging techniques were essential to reach this diagnosis.

5.
Rev. chil. radiol ; 25(2): 47-49, jun. 2019. tab, graf, ilus
Artigo em Espanhol | LILACS | ID: biblio-1013849

RESUMO

Resumen: Introducción: El objetivo de este estudio fue desarrollar un modelo predictivo sobre la presencia de tuberculosis pulmonar activa utilizando datos clínico-epidemiológicos y hallazgos de radiografía simple (Rx) y tomografía computadorizada (TC) de tórax. Material y métodos: Se realizó un estudio observacional, retrospectivo, descriptivo y analítico, que recopiló 22 variables clínico-epidemiológicas, 11 hallazgos radiológicos en Rx de tórax y 23 en la TC, que se realizaron en pacientes con sospecha clínica de tuberculosis pulmonar durante un período de 10 años. Se aplicó un modelo de regresión logística multivariado a los predictores potenciales de cultivo positivo, obteniendo un modelo predictivo. Resultados: Se recogieron 1.540 pacientes con sospecha clínica de tuberculosis a los que se les realizó Rx y TC torácico. El cultivo fue positivo en 101 casos. Se utilizó un proceso de eliminación hacia atrás para obtener el mejor conjunto de variables predictivas. Se obtuvieron 24 variables que fueron significativas (6 clínicas, 5 de Rx y 13 de TC) y se les asignó una puntuación. A la suma de estas puntuaciones se restó la edad en años multiplicada por 0,03. El modelo sugiere el diagnóstico de tuberculosis pulmonar activa en pacientes con una puntuación superior a 1,845. Obtuvo una sensibilidad de 85,1%, especificidad de 83,6%, valor predictivo positivo de 26,6%, y valor predictivo negativo de 98,7%. El área bajo la curva ROC fue de 0,9163. Conclusión: Este sistema de puntuación basado en criterios clínico-epidemiológicos y hallazgos radiológicos puede ayudar a diagnosticar tuberculosis pulmonar activa en casos de sospecha diagnóstica.


Abstract:Introduction: The objective of this study was to develop a predictive model on the presence of active pulmonary tuberculosis using clinical-epidemiological data and findings of chest radiography and thoracic computed tomography (CT). Material and methods: An observational, retrospective, descriptive and analytical study was conducted, which collected 22 clinical and epidemiological variables, 11 radiological findings on chest x-ray and 23 on CT that were performed in patients with clinical suspicion of pulmonary tuberculosis during a period of 10 years. A multivariate logistic regression model was applied to the potential predictors of positive culture, obtaining a predictive model. Results: We collected 1,540 patients with clinical suspicion of tuberculosis who underwent radiography and thoracic CT. The culture was positive in 101 cases. A backward elimination process was used to obtain the best set of predictive variables. We obtained 24 variables that were significant (6 clinical, 5 of chest plain films and 13 of CT) and were assigned a score. The sum of these scores was subtracted from the age in years and multiplied by 0.03. The model suggests the diagnosis of active pulmonary tuberculosis in patients with a score higher than 1.845. The model obtained a sensitivity of 85.1%, specificity of 83.6%, positive predictive value of 26.6, and negative predictive value of 98.7%. The area under the ROC curve was 0.9163. Conclusion: This scoring system based on clinical-epidemiological criteria and radiological findings can help rule out active pulmonary tuberculosis in cases of diagnostic suspicion.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Tuberculose Pulmonar/diagnóstico por imagem , Radiografia Torácica , Tomografia Computadorizada por Raios X , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/epidemiologia , Modelos Logísticos , Epidemiologia Descritiva , Análise Multivariada , Valor Preditivo dos Testes , Estudos Retrospectivos , Curva ROC , Sensibilidade e Especificidade , Fatores Etários
6.
Sci Total Environ ; 598: 856-866, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28458203

RESUMO

The aim of this work was to demonstrate the feasibility of the application of biosorption in the treatment of metal polluted wastewaters through the development of several pilot plants to be implemented by the industry. The use as biosorbents of both the brown seaweed Fucus vesiculosus and a sugar beet pulp was investigated to remove heavy metal ions from a wastewater generated in an electroplating industry: Industrial Goñabe (Valladolid, Spain). Batch experiments were performed to study the effects of pH, contact time and initial metal concentration on metal biosorption. It was observed that the adsorption capacity of the biosorbents strongly depended on the pH, increasing as the pH rises from 2 to 5. The adsorption kinetic was studied using three models: pseudo first order, pseudo second order and Elovich models. The experimental data were fitted to Langmuir and Freundlich isotherm models and the brown alga F. vesiculosus showed higher metal uptake than the sugar beet pulp. The biomasses were also used for zinc removal in fixed-bed columns. The performance of the system was evaluated in different experimental conditions. The mixture of the two biomasses, the use of serial columns and the inverse flow can be interesting attempts to improve the biosorption process for large-scale applications.

7.
Eur Surg Res ; 56(3-4): 164-79, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27035593

RESUMO

BACKGROUND: Renal injuries are relatively frequent in abdominal trauma. In some cases, adhesives and sealants can be used to repair and preserve injured organs. This paper describes the behaviour of three biomaterials - TachoSil®, GelitaSpon®, and a new elastic cyanoacrylate (CyA), Adhflex® - in standardized experimental renal injuries. METHODS: Ninety male Wistar rats (300-350 g) were used. A Stiefel Biopsy Punch (8 mm diameter, 3 mm depth) was used to create injuries to the anterior kidney to evaluate wound healing. The animals were divided into five groups: (1) sham (n = 3); (2) control (n = 6), untreated, standard punch injury created on the anterior left kidney; (3) TachoSil® (n = 27), punch injury treated with TachoSil®; (4) GelitaSpon® (n = 27), punch injury treated with GelitaSpon®, and (5) Adhflex® (n = 27), punch injury treated with the new elastic CyA adhesive. The parameters studied were bleeding time, peritoneal adhesions, and histopathological evaluation of wound healing on days 2, 6, and 18, including measurements of the gap between wound edges, inflammatory reaction (CD68), and vascular neoformation (CD31). RESULTS: The bleeding time was significantly shorter (27.7 ± 12.9 s) in the Adhflex® group than in the control (135.8 ± 11.6 s; p < 0.01), TachoSil® (77.5 ± 7.4 s; p < 0.05), and GelitaSpon® (82.5 ± 14.4 s; p < 0.05) groups. The incidence of intraperitoneal adhesions in the animals treated with Adhflex® was 3.6 times higher than in the non-treated group. It was also higher (p < 0.04) than in the groups treated with TachoSil® and GelitaSpon®. The time point with the largest gap between the wound edges and most abundant granulation tissue was at day 6. The largest gap after 18 days was reported for the Adhflex® adhesive. With regard to the markers CD31 and CD68, Adhflex® showed the largest areas 2 days after surgery, but no differences were found after 6 and 18 days versus the other treatments. The expression of the immunomarkers on the renal samples treated with Adhflex® was consistent with a normal healing process. CONCLUSIONS: In this experimental model of renal injuries, the new elastic CyA (Adhflex®) resulted in the shortest bleeding time. It offers rapid sealing of the bleeding produced by renal injuries, fixation to adjacent tissues, and reduced occurrences of relapse. The evolution of the scarring is similar to other procedures. Given that traumatic renal injuries are always an emergency due to haemorrhage, Adhflex® might offer additional benefits over conventional treatment methods in human clinical practice.


Assuntos
Celulose/farmacologia , Cianoacrilatos/farmacologia , Fibrinogênio/farmacologia , Rim/lesões , Trombina/farmacologia , Adesivos Teciduais/farmacologia , Cicatrização , Animais , Tempo de Sangramento , Combinação de Medicamentos , Imuno-Histoquímica , Rim/patologia , Modelos Logísticos , Masculino , Ratos , Ratos Wistar , Aderências Teciduais/epidemiologia
8.
IET Nanobiotechnol ; 9(5): 252-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26435277

RESUMO

This study focuses on the green synthesis of noble metal nanoparticles (silver (Ag) and platinum (Pt)) and how the size and shape of the nanoparticles produced can be controlled through changes in the initial pH value of the precursor solution. The nanoparticles were characterised by ultra-violet-visible spectroscopy, transmission electron microscopy and X-ray diffraction. This simple and environmentally friendly method allows the synthesis of diverse nanostructures in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally adding seed crystallites. The antibacterial effects of Ag nanoparticles and catalytic properties of Pt nanoparticles were explored for future promising biotechnological approaches in different fields.


Assuntos
Biotecnologia/métodos , Citrus sinensis/química , Nanopartículas Metálicas/química , Extratos Vegetais/metabolismo , Platina/química , Prata/química , Aeromonas/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Extratos Vegetais/química , Platina/metabolismo , Platina/farmacologia , Prata/metabolismo , Prata/farmacologia
9.
Am J Case Rep ; 16: 491-5, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26212619

RESUMO

BACKGROUND Primary malignant melanoma of the esophagus (PMME) is a rare cancer with a poor prognosis. It is often difficult to differentiate from non-epithelial malignant tumors, and immunohistochemical staining may be needed to diagnose the condition. The mainstay of treatment is usually surgical with curative or palliative intent, since radio- and chemotherapy do not really improve the outcome. The average survival rate after surgery is 34.5 months. At the time of diagnosis, 40-80% of cases have local regional lymph node metastases. CASE REPORT The case of a 67-year-old male patient with PMME is reported. He presented with progressive dysphagia. A computerized tomography was performed in which a polypoid mass was observed in the distal esophagus. It was originally suspected to be an adenocarcinoma, but was subsequently correctly diagnosed by immunohistochemical staining with HMB-45 antibody and by the presence of S-100 protein. A subtotal esophagectomy was performed. CONCLUSIONS Very few cases of PMME have been reported in the literature and there is only limited clinical experience with this disease. Therefore, it is very difficult to establish clear criteria for clinical recognition of this type of melanoma. Early histopathological confirmation of the character is essential for further treatment in case of confirmation of malignancy.


Assuntos
Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/terapia , Melanoma/diagnóstico , Melanoma/terapia , Idoso , Humanos , Masculino
10.
Methods Mol Biol ; 1224: 163-76, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25416257

RESUMO

Development of a system for direct transfer of antifungal candidate genes into European chestnut (Castanea sativa) would provide an alternative approach to conventional breeding for production of chestnut trees that are tolerant to ink disease caused by Phytophthora spp. Overexpression of genes encoding PR proteins (such as thaumatin-like proteins), which display antifungal activity, may represent an important advance in control of the disease. We have used a chestnut thaumatin-like protein gene (CsTL1) isolated from European chestnut cotyledons and have achieved overexpression of the gene in chestnut somatic embryogenic lines used as target material. We have also acclimatized the transgenic plants and grown them on in the greenhouse. Here, we describe the various steps of the process, from the induction of somatic embryogenesis to the production of transgenic plants.


Assuntos
Fagaceae/crescimento & desenvolvimento , Fagaceae/genética , Engenharia Genética/métodos , Agrobacterium tumefaciens/genética , Agrobacterium tumefaciens/crescimento & desenvolvimento , Técnicas de Cocultura , Fagaceae/fisiologia , Regeneração , Sementes/crescimento & desenvolvimento , Transformação Genética
11.
Surg Today ; 45(8): 939-56, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25344231

RESUMO

This paper presents a review of the use of cyanoacrylate adhesives (CA) in general surgery and digestive surgery, studies the mechanisms of action and interactions of CAs in adherent tissues, and compiles data on the latest experimental and clinical applications. More than seven million traumatic injuries are estimated to occur every year, and between 26 and 90 million surgical procedures using different techniques are performed to close the resulting wounds. Traditional methods not only are both useful and effective, but also have some drawbacks. This review covers a considerable number of surgical procedures for which CAs had satisfactory results. The adhesive facilitated the healing of very diverse tissues, such as solid organs, vascular tissue or the abdominal wall. In other cases, no significant differences were found when CA was compared to traditional methods, with the adhesive standing out as a simple and reliable solution. The number of procedures in which CA was detrimental was very low. This review also collects and describes these. In conclusion, the surgical fields and procedures in which CA was successfully used are highly diverse. This review will allow physicians to determine which techniques were first used experimentally, but finally settled in clinical practice as feasible alternatives to standard treatments.


Assuntos
Cianoacrilatos/uso terapêutico , Procedimentos Cirúrgicos Operatórios/métodos , Adesivos Teciduais/uso terapêutico , Técnicas de Fechamento de Ferimentos , Cianoacrilatos/administração & dosagem , Cianoacrilatos/farmacologia , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Embolização Terapêutica , Embucrilato , Hemostáticos , Herniorrafia , Humanos , Laparoscopia , Adesivos Teciduais/administração & dosagem , Adesivos Teciduais/farmacologia , Varizes/terapia , Procedimentos Cirúrgicos Vasculares/métodos , Cicatrização , Ferimentos e Lesões/cirurgia
12.
Res Microbiol ; 165(9): 794-802, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25283724

RESUMO

Aeromonas hydrophila is a facultative anaerobe which, under conditions of oxygen depletion, uses Fe(III) as electron acceptor. A. hydrophila produces pili during growth with Fe(III). The study was focused on the characterization of the morphology, the electrical properties and the nature of the bacterial pili. Scanning electron microscopy and conductive-probe atomic force microscopy revealed the presence of filaments between cells and substrate and their conductive nature. Our results indicate that pili of A. hydrophila strain A might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(III) oxides and, in addition, the possibility of playing a role in inter/intra species signaling. Quorum sensing (QS) is recognized as one of the main regulatory ways for extracellular polymeric substances (EPS) production and biofilm formation. We present evidence that nanowire formation can be regulated by addition of synthetic acyl-homoserine lactones (AHL). These conductive pili may be involved in various interactions, and their protein components might be usable in the future for biotechnological approaches in materials science.


Assuntos
Aeromonas hydrophila/fisiologia , Condutividade Elétrica , Microbiologia Ambiental , Nanofios/microbiologia , Acil-Butirolactonas/metabolismo , Aeromonas hydrophila/metabolismo , Aeromonas hydrophila/ultraestrutura , Compostos Férricos/metabolismo , Fímbrias Bacterianas/ultraestrutura , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Percepção de Quorum
13.
Biofouling ; 30(4): 501-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24673176

RESUMO

The aim of this work was to investigate the production of extracellular polymeric substances (EPS) by Aeromonas hydrophila grown under anaerobic conditions. EPS composition was studied for planktonic cells, cells attached to carbon fibre supports using a soluble ferric iron source and cells grown with a solid ferric iron mineral (gossan). Conventional spectrophotometric methods, Fourier transform infrared (FTIR) and confocal laser scanning microscopy (CLSM) were used to determine the main components in the biofilm extracted from the cultures. The key EPS components were proteins, indicating their importance for electron transfer reactions. Carbohydrates were observed mostly on the mineral and contained terminal mannosyl and/or terminal glucose, fucose and N-acetylgalactosamine residues.


Assuntos
Aeromonas hydrophila/metabolismo , Polímeros/metabolismo , Biofilmes , Microscopia Confocal , Polímeros/análise , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Rev. colomb. radiol ; 25(2): 3969-3971, 2014. graf
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-995206

RESUMO

Se presenta el caso de un paciente con dolor abdominal de seis días de evolución, anorexia y pérdida de peso. Se le realiza una TC en la que se aprecia una herniación de la pared del borde antimesentérico del íleon, la cual produjo luego una seudoobstrucción y una peritonitis fecaloidea tras una perforación intestinal. La hernia de Richter presenta una clínica lentamente progresiva, por lo cual es común que se demore su diagnóstico. La cirugía tardía aumenta la morbimortalidad asociada


This is the case of a patient presenting abdominal pain for 6 days, as well as anorexia and weight loss. A CT scan is performed, showing a hernia of the antimesenteric border of the distal ileum, resulting in pseudo-obstruction and peritonitis due to intestinal perforation. Richter's hernia presents a slowly progressive clinical presentation, with often delayed diagnosis. Late surgery increases associated morbidity and mortality


Assuntos
Humanos , Obstrução Intestinal , Peritonite , Tomografia Computadorizada por Raios X , Hérnia Abdominal
15.
IET Nanobiotechnol ; 7(3): 109-16, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24028809

RESUMO

The increasing demand and limited natural resources of noble metals make its recovery from dilute industrial wastes attractive, especially when using environmentally friendly methods. Nowadays, the high impact that nanotechnology is having in both science and society offers new research possibilities. Gold and silver nanoparticles were biosynthesised by a simple method using different algae as reducing agent. The authors explored the application of dead algae in an eco-friendly procedure. The nanoparticle formation was followed by UV-vis absorption spectroscopy and transmission electron microscopy. The functional groups involved in the bioreduction were studied by Fourier transform infrared spectroscopy.


Assuntos
Chondrus/metabolismo , Nanopartículas Metálicas/química , Biomassa , Ouro/química , Química Verde , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Prata/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Prep Biochem Biotechnol ; 43(8): 815-27, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23876140

RESUMO

The sorption of Fe(II) and Fe(III) by extracellular polymeric substances (EPS) of acidophilic bacteria Acidiphilium 3.2Sup(5) and Acidithiobacillus ferrooxidans, harvested from the ecosystem of the Tinto River (Huelva, Spain), was investigated. EPS from mixed cultures of both bacteria (EPS(mixed)) and pure cultures of A. 3.2Sup(5) (EPS(pure)) were extracted with ethylenediamine tetraacetic acid (EDTA) and were characterized by Fourier-transform infrared (FTIR), electron photoemission (XPS), x-ray diffraction (DRX), and energy dispersive x-ray (EDX) spectroscopy and scanning electron microscopy (SEM). EPS pure were loaded, in sorption tests, with Fe(II) and Fe(III). The results obtained indicate that the biochemical composition and structure of EPS(mixed) was very similar to that of EPS(pure). Besides, results indicate that EPS(mixed) adsorbed Fe(II) and Fe(III) by preferential interaction with the carboxyl group, which favored the formation of Fe(II)/Fe(III) oxalates. These species were also formed in EPS(pure) loaded with Fe(II)/Fe(III). All this behavior suggested that the sorption of iron by EPS(mixed) was similar to sorption of EPS(pure), which fitted the Freundlich model. Thus, the iron uptake of EPS(mixed) reached 516.7 ± 23.4 mg Fe/g-EPS at an initial concentration of 2.0 g/L of Fe(total) and Fe(II)/Fe(III) ratio of 1.0.


Assuntos
Proteínas de Bactérias/química , Compostos Férricos/química , Compostos Ferrosos/química , Polissacarídeos Bacterianos/química , Acidiphilium/química , Acidiphilium/ultraestrutura , Acidithiobacillus/química , Acidithiobacillus/ultraestrutura , Adsorção , Proteínas de Bactérias/isolamento & purificação , Microscopia Eletrônica de Varredura , Oxirredução , Polissacarídeos Bacterianos/isolamento & purificação , Rios/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Tree Physiol ; 32(11): 1389-402, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23086811

RESUMO

The availability of a system for direct transfer of antifungal candidate genes into European chestnut (Castanea sativa Mill.) would offer an alternative approach to conventional breeding for production of chestnut trees tolerant to ink disease caused by Phytophthora spp. For the first time, a chestnut thaumatin-like protein gene (CsTL1), isolated from chestnut cotyledons, has been overexpressed in three chestnut somatic embryogenic lines. Transformation experiments have been performed using an Agrobacterium tumefaciens Smith and Townsend vector harboring the neomycin phosphotransferase (NPTII) selectable and the green fluorescent protein (EGFP) reporter genes. The transformation efficiency, determined on the basis of the fluorescence of surviving explants, was clearly genotype dependent and ranged from 32.5% in the CI-9 line to 7.1% in the CI-3 line. A total of 126 independent transformed lines were obtained. The presence and integration of chestnut CsTL1 in genomic DNA was confirmed by polymerase chain reaction (PCR) and Southern blot analyses. Quantitative real-time PCR revealed that CsTL1 expression was up to 13.5-fold higher in a transgenic line compared with its corresponding untransformed line. In only one of the 11 transformed lines tested, expression of the CsTL1 was lower than the control. The remaining 115 transformed lines were successfully subjected to cryopreservation. Embryo proliferation was achieved in all of the transgenic lines regenerated and the transformed lines showed a higher mean number of cotyledonary stage embryos and total number of embryos per embryo clump than their corresponding untransformed lines. Transgenic plants were regenerated after maturation and germination of transformed somatic embryos. Furthermore, due to the low plantlet conversion achieved, axillary shoot proliferation cultures were established from partially germinated embryos (only shoot development), which were multiplied and rooted according to procedures already established. Transgenic plants were acclimatized and grown in a greenhouse. No phenotypic differences were found with control plants, suggesting no potential cytotoxic effects of the green fluorescent protein. The results reported in the present work could be considered as a first step toward the production of fungal-disease tolerant cisgenic chestnut plants.


Assuntos
Fagaceae/genética , Proteínas de Plantas/genética , Sementes/genética , Transformação Genética , Agrobacterium tumefaciens , Cruzamento , Cotilédone/anatomia & histologia , Cotilédone/genética , Cotilédone/crescimento & desenvolvimento , Criopreservação , Cisteína/metabolismo , Fagaceae/anatomia & histologia , Fagaceae/crescimento & desenvolvimento , Expressão Gênica , Vetores Genéticos , Genótipo , Germinação , Proteínas de Fluorescência Verde , Canamicina Quinase/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/anatomia & histologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Técnicas de Embriogênese Somática de Plantas , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Sementes/anatomia & histologia , Sementes/crescimento & desenvolvimento , Árvores
18.
Methods Mol Biol ; 877: 247-63, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22610633

RESUMO

The ability of plants to remove pollutants from the environment is currently used in a simple and low-cost cleaning technology known as phytoremediation. Unfortunately, little is known about the metabolic pathways involved in the transformation of xenobiotic compounds and the ability of certain plants to tolerate, detoxify, and store high concentrations of heavy metals. Plant cell and tissue culture is considered an important tool for fundamental studies that provide information about the plant-contaminant relationships, help to predict plant responses to environmental contaminants, and improve the design of plants with enhanced characteristics for phytoremediation. Callus, cell suspensions, hairy roots, and shoot multiplication cultures are used to study the interactions between plants and pollutants under aseptic conditions. Many plant species have an inherent ability to accumulate/metabolize a variety of pollutants, but they normally produce little biomass. However, fast-growing trees are excellent candidates for phytoremediation because of their rapid growth, extensive root system, and high water uptake. This chapter outlines the in vitro plant production of both somaclonal variants and transgenic plants of Populus spp. that exhibit high tolerance to heavy metals.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Metais Pesados/análise , Populus/química , Populus/crescimento & desenvolvimento , Técnicas de Cultura de Tecidos , Biodegradação Ambiental , Poluentes Ambientais/metabolismo , Metais Pesados/metabolismo
19.
Cir Esp ; 90(2): 114-20, 2012 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-22225611

RESUMO

INTRODUCTION: The aim of the study is to evaluate the limb salvage rate achieved by treating locally advanced extremity sarcoma and melanoma by hyperthermic isolated limb perfusion with melphalan and TNF-α (ILP-MT). MATERIAL AND METHODS: A retrospective study was conducted on patients suffering from locally advanced soft tissue sarcoma and melanoma of the limb and treated by means of ILP-MT between November 2001 and February 2010. The response rate, toxicity, complications, disease free intervals, overall survival and limb salvage rate were evaluated. RESULTS: A total of 30 patients (19 females and 11 males) with a median age of 60 years (14-82) were treated by this technique. The overall response rate was 93.4% (complete, 46.7%; partial 46.7%); the mean follow-up was 23 months. The median duration of response was 5 months (0-62), The median overall survival was 13.5 months (range 1 - 62). Limb salvage rate was 86.7%. Eleven patients are currently alive (5 without disease, 2 with residual disease on treatment, 2 with local progression and 2 with systemic progression). CONCLUSION: With the use of ILP-MT we have avoided the amputation of 26 limbs affected by locally advanced sarcoma or melanoma. ILP-MT is feasible and safe in a multidisciplinary environment.


Assuntos
Antineoplásicos Alquilantes/administração & dosagem , Braço , Quimioterapia do Câncer por Perfusão Regional , Hipertermia Induzida , Perna (Membro) , Salvamento de Membro , Melanoma/tratamento farmacológico , Melfalan/administração & dosagem , Sarcoma/tratamento farmacológico , Neoplasias de Tecidos Moles/tratamento farmacológico , Fator de Necrose Tumoral alfa/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia do Câncer por Perfusão Regional/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
20.
Tree Physiol ; 31(10): 1152-60, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21964478

RESUMO

The Castanea sativa SCL1 gene (CsSCL1) has previously been shown to be induced by auxin during adventitious root (AR) formation in rooting-competent microshoots. However, its expression has not previously been analyzed in rooting-incompetent shoots. This study focuses on the regulation of CsSCL1 during maturation and the role of the gene in the formation of AR. The expression of CsSCL1 in rooting-incompetent microshoots and other tissues was investigated by quantitative reverse transcriptase--polymerase chain reaction. The analysis was complemented by in situ hybridization of the basal segments of rooting-competent and --incompetent microshoots during AR induction, as well as in AR and lateral roots. It was found that CsSCL1 is upregulated by auxin in a cell-type- and phase-dependent manner during the induction of AR. In root-forming shoots, CsSCL1 mRNA was specifically located in the cambial zone and derivative cells, which are rooting-competent cells, whereas in rooting-incompetent shoots the hybridization signal was more diffuse and evenly distributed through the phloem and parenchyma. CsSCL1 expression was also detected in lateral roots and axillary buds. The different CsSCL1 expression patterns in rooting-competent and -incompetent microshoots, together with the specific location of transcripts in cell types involved in root meristem initiation and in the root primordia of AR and lateral roots, indicate an important role for the gene in determining whether certain cells will enter the root differentiation pathway and its involvement in meristem maintenance.


Assuntos
Fagaceae/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Fagaceae/crescimento & desenvolvimento , RNA Mensageiro/metabolismo
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