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1.
Clin Radiol ; 78(9): e620-e626, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37407369

RESUMEN

AIM: To compare the success and complication rates of computed tomography (CT)-guided percutaneous core-needle biopsy (PCNB) based on the density of lung nodules, using propensity score matching (PSM). MATERIALS AND METHODS: This single-centre retrospective study included 1,312 PCNB cases of lung lesions, including solid (n=1,120), part-solid (n=115), and non-solid nodules (n=77), that were detected between March 2013 and March 2021. The diagnostic accuracy and complication rates of pneumothorax and pulmonary haemorrhage were analysed before PSM. To perform PSM, part-solid and non-solid nodules were combined and newly defined as sub-solid nodules. The diagnostic accuracy and complication rates of pneumothorax and pulmonary haemorrhage were then compared between solid and sub-solid nodules after PSM. RESULTS: Among the 1,312 included cases, the success rate and incidence of pneumothorax after CT-guided PCNB for solid, part-solid, and non-solid nodules were not statistically different (p=0.080 and 0.410). However, the rates of overall pulmonary haemorrhage showed statistical differences (p<0.001), particularly between solid and part-solid nodules (p<0.001) and between solid and non-solid nodules (p<0.001). After PSM, the incidence rates of overall pulmonary haemorrhage in solid and sub-solid nodules were 8.9% (17/192) and 29.7% (44/182), respectively, showing a statistically significant difference (p<0.001). CONCLUSION: There is increased risk of haemorrhage in CT-guided needle biopsy of sub-solid nodules compared to solid nodules. Increased emphasis should be placed on the risk of pulmonary haemorrhage when consenting these patients.


Asunto(s)
Enfermedades Pulmonares , Neoplasias Pulmonares , Neumotórax , Humanos , Neumotórax/epidemiología , Neumotórax/etiología , Neoplasias Pulmonares/diagnóstico por imagen , Estudios Retrospectivos , Puntaje de Propensión , Biopsia Guiada por Imagen/efectos adversos , Biopsia Guiada por Imagen/métodos , Biopsia con Aguja Gruesa/efectos adversos , Hemorragia/epidemiología , Hemorragia/etiología , Tomografía Computarizada por Rayos X , Pulmón/diagnóstico por imagen , Pulmón/patología
2.
Plant Biol (Stuttg) ; 22(5): 850-862, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32329163

RESUMEN

Salt stress negatively affects growth and development of plants. However, it is hypothesized that plant growth-promoting endophytic bacteria can greatly alleviate the adverse effects of salinity and can promote growth and development of plants. In the present research, we aimed to isolate endophytic bacteria from halotolerant plants and evaluate their capacity for promoting crop plant growth. The bacterial endophytes were isolated from selected plants inhabiting sand dunes at Pohang beach, screened for plant growth-promoting traits and applied to rice seedlings under salt stress (NaCl; 150 mm). Out of 59 endophytic bacterial isolates, only six isolates, i.e. Curtobacterium oceanosedimentum SAK1, Curtobacterium luteum SAK2, Enterobacter ludwigii SAK5, Bacillus cereus SA1, Micrococcus yunnanensis SA2, Enterobacter tabaci SA3, resulted in a significant increase in the growth of Waito-C rice. The cultural filtrates of bacterial endophytes were tested for phytohormones, including indole-3-acetic acid, gibberellins and organic acids. Inoculation of the selected strains considerably reduced the amount of endogenous ABA in rice plants under NaCl stress, however, they increased GSH and sugar content. Similarly, these strains augmented the expression of flavin monooxygenase (OsYUCCA1) and auxin efflux carrier (OsPIN1) genes under salt stress. In conclusion, the pragmatic application of the above selected bacterial strains alleviated the adverse effects of NaCl stress and enhanced rice growth attributes by producing various phytohormones.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Endófitos , Oryza , Tolerancia a la Sal , Actinobacteria/fisiología , Endófitos/fisiología , Enterobacter/fisiología , Micrococcus/fisiología , Oryza/microbiología , Raíces de Plantas/microbiología , Tolerancia a la Sal/fisiología
3.
Plant Biol (Stuttg) ; 22(3): 514-521, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31965672

RESUMEN

Information on the optimal conditions to promote the germination of Lamprocapnos spectabilis (L.) Fukuhara seeds is limited; consequently, this study was conducted to establish the requirements to break seed dormancy and promote germination. The selected seeds had morphophysiological dormancy and had not begun embryo development. To study the dormancy breaking and embryo development processes, seeds were subjected to constant or changing temperature treatments during moist stratification. High temperature and humidity resulted in vigorous embryo growth, with the longest embryos occurring after 1 month of incubation at 20 °C. At 4 °C, the seeds required incubation period of at least 3 months to germinate. Embryo growth and germination were higher with changing high and low temperatures than under a constant temperature, and changing temperatures also considerably changed the endogenous hormone levels, embryo development and germination. Bioactive gibberellin (GA) content was higher in seeds incubated at 20 °C for 1 month, then at 4 °C for 2 months. The content of endogenous abscisic acid in seeds subjected to the same treatment decreased by 97.6% compared with that of the untreated seeds. Embryo growth and seed germination require changing high and low temperatures; however, exogenous GA3 could substitute for high temperatures, as it also causes accelerated germination. In this study, the seeds of L. spectabilis were identified as an intermediate simple type, a sub-level of morphophysiologically dormant seeds.


Asunto(s)
Germinación , Latencia en las Plantas , Semillas , Ácido Abscísico/metabolismo , Giberelinas/metabolismo , Papaveraceae/fisiología , Semillas/química , Temperatura
4.
Clin Radiol ; 74(5): 407.e19-407.e28, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30837076

RESUMEN

AIM: To compare the therapeutic efficacy and safety of transarterial chemoembolisation (TACE) for hepatocellular carcinoma (HCC) within the Milan criteria with or without the use of cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Patients with HCC within the Milan criteria who underwent conventional angiography-guided TACE (Angio-TACE group: 58 patients from January 2010 to December 2011) were compared with those who underwent CBCT-guided TACE (CBCT-TACE group: 55 patients from January 2013 to December 2014). Local progression-free survival (LPFS), progression-free survival (PFS), and overall survival (OS) were compared. Adverse events after TACE were also investigated. RESULTS: Baseline characteristics were balanced between the two groups. LPFS was significantly longer in the CBCT-TACE group than in the Angio-TACE group (median: not reached for 36 versus 19.2 months, respectively; Log-rank p=0.029). In multivariable Cox regression analysis, CBCT guidance had a significantly lower risk of local progression or death (adjusted hazard ratio: 0.585; 95% confidence interval, 0.344-0.995; p=0.048); however, there was no significant difference in PFS (3-year PFS: 15.9% versus 26.8%, respectively; p=0.122) or OS (3-year OS: 85% versus 88.2%, respectively; p=0.761) between the Angio-TACE and CBCT-TACE groups. Post-embolisation syndrome occurred significantly less frequently in the CBCT-TACE group (p=0.002). CONCLUSION: CBCT-guided TACE could improve local tumour control for HCC within Milan criteria and showed fewer cases of post-embolisation syndrome.


Asunto(s)
Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica/métodos , Neoplasias Hepáticas/terapia , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Quimioembolización Terapéutica/efectos adversos , Tomografía Computarizada de Haz Cónico , Femenino , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Retratamiento/estadística & datos numéricos , Estudios Retrospectivos , Resultado del Tratamiento , Carga Tumoral
5.
Sci Rep ; 8(1): 3370, 2018 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-29463852

RESUMEN

Insertion of halogens such as bromine or iodine affects the electronic polarizability of ions and the local field inside the medium, and thus modifies the refractive index. Acquiring precise knowledge of the dispersion of refractive index and ultimately tailoring conventional semiconductors for wide-range refractive index control have been a vital issue to resolve before realizing advanced organic optoelectronic devices. In this report, dispersions of the refractive index of a single crystal tetramethyltetraselenafulvalene [C10H12Se4] (TMTSF) are thoroughly studied from broadband interference modulations of photoluminescence (PL) spectra at various temperatures and doping levels. A large enhancement of the refractive index, more than 20% of the intrinsic value, is achieved with inclusion of a small composition of iodide ions, while the structural and optical properties remain mostly intact. Nearly temperature independent dispersion of the refractive index suggests that, unlike most polymers in which the thermal expansion coefficient dominates over the change of polarizability with temperature, the latter enhances significantly and may become more or less comparable to the thermal expansion coefficient given by 1.71 × 10-4/K, when single crystal TMTSF is doped by iodine.

6.
Plant Biol (Stuttg) ; 17(5): 1013-22, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25940948

RESUMEN

This study aimed to elucidate the role played by Enterobacter asburiae KE17 in the growth and metabolism of soybeans during copper (100 µm Cu) and zinc (100 µm Zn) toxicity. When compared to controls, plants grown under Cu and Zn stress exhibited significantly lower growth rates, but inoculation with E. asburiae KE17 increased growth rates of stressed plants. The concentrations of plant hormones (abscisic acid and salicylic acid) and rates of lipid peroxidation were higher in plants under heavy metal stress, while total chlorophyll, carotenoid content and total polyphenol concentration were lower. While the bacterial treatment reduced the abscisic acid and salicylic acid content and lipid peroxidation rate of Cu-stressed plants, it also increased the concentration of photosynthetic pigments and total polyphenol. Moreover, the heavy metals induced increased accumulation of free amino acids such as aspartic acid, threonine, serine, glycine, alanine, leucine, isoleucine, tyrosine, proline and gamma-aminobutyric acid, while E. asburiae KE17 significantly reduced concentrations of free amino acids in metal-affected plants. Co-treatment with E. asburiae KE17 regulated nutrient uptake by enhancing nitrogen content and inhibiting Cu and Zn accumulation in soybean plants. The results of this study suggest that E. asburiae KE17 mitigates the effects of Cu and Zn stress by reprogramming plant metabolic processes.


Asunto(s)
Cobre/toxicidad , Enterobacter/fisiología , Glycine max/microbiología , Reguladores del Crecimiento de las Plantas/metabolismo , Zinc/toxicidad , Ácido Abscísico/metabolismo , Aminoácidos/metabolismo , Secuencia de Bases , Carotenoides/metabolismo , Clorofila/metabolismo , Enterobacter/genética , Peroxidación de Lípido/efectos de los fármacos , Datos de Secuencia Molecular , Filogenia , Polifenoles/metabolismo , Ácido Salicílico/metabolismo , Análisis de Secuencia de ADN , Glycine max/efectos de los fármacos , Glycine max/fisiología , Estrés Fisiológico
7.
Sci Rep ; 5: 10126, 2015 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-25997075

RESUMEN

Plasma etching was demonstrated to be a promising tool for generating self-organized nano-patterns on various commercial films. Unfortunately, dynamic scaling approach toward fundamental understanding of the formation and growth of the plasma-induced nano-structure has not always been straightforward. The temporal evolution of self-aligned nano-patterns may often evolve with an additional scale-invariance, which leads to breakdown of the well-established dynamic scaling law. The concept of a bifractal interface is successfully applied to reticular patterns induced by oxygen plasma on the surface of polymer films. The reticular pattern, composed of nano-size self-aligned protuberances and underlying structure, develops two types of anomalous dynamic scaling characterized by super-roughening and intrinsic anomalous scaling, respectively. The diffusion and aggregation of short-cleaved chains under the plasma environment are responsible for the regular distribution of the nano-size protuberances. Remarkably, it is uncovered that the dynamic roughening of the underlying structure is governed by a relaxation mechanism described by the Edwards-Wilkinson universality class with a conservative noise. The evidence for the basic phase, characterized by the negative roughness and growth exponents, has been elusive since its first theoretical consideration more than two decades ago.

8.
Clin Radiol ; 69(6): e285-90, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24630134

RESUMEN

AIM: To assess the relationship between chest computed tomography (CT) findings of patients with toxocariasis and levels of serological markers. MATERIALS AND METHODS: A total of 38 cases of patients diagnosed with toxocariasis by enzyme-linked immunosorbent assay (ELISA), CT, and serological markers were retrospectively reviewed. The presence of nodule with or without ground-glass opacity (GGO) halo, consolidation, focal GGO, pleural effusion, and lymphadenopathy at chest CT were evaluated. Statistical analysis was performed with the Fisher's exact test. RESULTS: The most common chest CT findings were nodule (n = 12, 31.6%) and focal GGO (n = 12, 31.6%). In patients with normal eosinophil levels, focal GGO (n = 9, 37.5%) was the most common finding. In contrast, nodule with a GGO halo (n = 7, 50%) was the most common finding in the eosinophilia group. Nodule with a GGO halo was more common in the eosinophilia group, with a statistically significant difference (p = 0.017). Nodule was more common in the eosinophilia group, and focal GGO was more common in the normal eosinophil group. CONCLUSION: The most common chest CT findings in toxocariasis were nodule with or without GGO halo, and focal GGO. In the eosinophilia group, nodule with a GGO halo was significantly more frequent. Other CT findings did not show a statistically significant relationship with serological markers.


Asunto(s)
Enfermedades Pulmonares Parasitarias/diagnóstico por imagen , Toxocariasis/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Ensayo de Inmunoadsorción Enzimática , Eosinófilos , Femenino , Humanos , Inmunoglobulina E/sangre , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector , Estudios Retrospectivos , Nódulo Pulmonar Solitario , Adulto Joven
9.
Artículo en Inglés | MEDLINE | ID: mdl-24645743

RESUMEN

Herein, we evaluated the feasibility of placing patients in a tilted head position as part of routine clinical practice for fractionated stereotactic radiotherapy (FSRT) of intracranial tumors using helical tomotherapy (HT), by assessing its dosimetric benefit and setup accuracy. We reviewed treatment plans of four cases that were to receive FSRT for brain lesions in normal and head-tilted positions. These patients underwent two computed tomography (CT) scans: first in the normal supine position and then in the supine position with the head tilted at a 458 angle. Two separate HT plans for each position were generated in these four patients, using the same planning parameters. Plans were compared for target conformity and dose homogeneity. Maximum and average doses to critical organs, including normal brain, brain stem, optic chiasm, optic nerves, and the eyes, were considered. To evaluate setup accuracy, patient movement during treatment was assessed by post-treatment megavoltage CT scans. Both HT plans achieved similar conformal and homogeneous dose coverage to the target. Head-tilted HT delivered lower average and maximum doses to critical organs in the cases where the tumor was located on the same plane with critical organs, particularly when they were not directly attached. Placement in the head-tilted position without a mouthpiece allowed for increased patient movement during treatment, while use of a mouthpiece reduced patient movement to even less than that observed for normal setup in the supine position. This pilot study showed that placement in a tilted head position for FSRT of intracranial tumors using HT may be of clinical use, but depends on the tumor location.

10.
Clin Exp Dermatol ; 39(1): 25-9, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24341477

RESUMEN

BACKGROUND: Androgenetic alopecia (AGA) is the most common type of hair loss, and is characterized by the transformation of terminal scalp hair into vellus hair. The epidemiology of AGA is not fully understood. A strong genetic basis has long been identified, although little is known of its nongenetic causes. AIM: To evaluate the association of AGA with a number of environmental factors, including smoking, drinking and sleeping habit. METHODS: In total, 3114 Korean individuals with AGA who attended any one of 17 dermatology clinics in 6 cities in South Korea between March 2011 and February 2012 were enrolled in the study. Epidemiologic a data were collected using a standard questionnaire. RESULTS: No association was seen between eating or sleeping habits and severity of hair loss. However, drinking and smoking were associated with the severity of AGA in male patients. We also found that patients of both genders with a family history had more advanced types of hair loss, and the age of onset of AGA in male patients with a family history was earlier than that in male patients without a family history. CONCLUSIONS: Although the evidence for an environmental influence on AGA remains very weak, we did find an association between hair loss severity and certain environmental factors, such as smoking and drinking. Family history with more severe hair loss and an earlier age of onset.


Asunto(s)
Alopecia/epidemiología , Adulto , Distribución por Edad , Edad de Inicio , Consumo de Bebidas Alcohólicas/efectos adversos , Alopecia/etiología , Alopecia/fisiopatología , Femenino , Humanos , Estilo de Vida , Masculino , Prevalencia , República de Corea/epidemiología , Factores de Riesgo , Distribución por Sexo , Sueño/fisiología , Fumar/efectos adversos
11.
Br J Radiol ; 85(1019): e987-94, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22674711

RESUMEN

OBJECTIVES: This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma. METHODS: 15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups. RESULTS: Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA. CONCLUSIONS: When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.


Asunto(s)
Carcinoma Hepatocelular/terapia , Ablación por Catéter/métodos , Embolización Terapéutica/métodos , Neoplasias Hepáticas/terapia , Animales , Hígado/irrigación sanguínea , Hígado/diagnóstico por imagen , Hígado/patología , Imagen de Perfusión , Conejos , Factores de Tiempo , Tomografía Computarizada por Rayos X
12.
J Hand Surg Eur Vol ; 34(5): 685-8, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19959449

RESUMEN

We report 17 patients with a subungual glomus tumour. All complained of pain and tenderness when touched, and nine patients experienced severe pain in the cold. A transungual approach with nail plate avulsion on one side was used in all cases. A surgical microscope was used to localise and dissect the tumour and to repair the nail bed and matrix. This method has produced good results, without local recurrence or postoperative nail plate deformity.


Asunto(s)
Tumor Glómico/diagnóstico , Tumor Glómico/cirugía , Microcirugia , Enfermedades de la Uña/cirugía , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/cirugía , Adulto , Estudios de Cohortes , Femenino , Humanos , Masculino , Microdisección , Persona de Mediana Edad , Enfermedades de la Uña/diagnóstico , Uñas Malformadas/prevención & control , Estudios Retrospectivos , Resultado del Tratamiento
13.
Br J Pharmacol ; 158(8): 1971-81, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19922538

RESUMEN

BACKGROUND AND PURPOSE: Benzoxathiolone derivatives have shown anti-inflammatory and immunomodulatory potential in acne and psoriatic disorders. However, little is known about the molecular basis for these pharmacological effects. In this study, we decided to investigate the anti-inflammatory actions of a benzoxathiolone derivative LYR-71, 6-methyl-2-propylimino-6,7-dihydro-5H-benzo[1,3]oxathiol-4-one, in interferon (IFN)-gamma-activated macrophages. EXPERIMENTAL APPROACH: RAW 264.7 macrophages or primary macrophages, derived from bone marrow of C3H/HeJ mice, were stimulated with IFN-gamma in the presence of LYR-71. Nitric oxide (NO) or chemokine production was measured by Griess reaction or enzyme-linked immunosorbent assay. RAW 264.7 cells were used to examine the molecular mechanisms of LYR-71 in modulating IFN-gamma-induced inflammatory responses. KEY RESULTS: LYR-71 down-regulated IFN-gamma-induced transcription of inducible NO synthase, IFN-gamma-inducible protein-10 and the monokine induced by IFN-gamma genes in macrophages. This effect was mediated by uncoupling tyrosine phosphorylation of the signal transducer and activator of transcription (STAT)-1 in response to IFN-gamma. LYR-71 directly inhibited the in vitro catalytic activity of Janus kinase (JAK)-2. Further, the inhibitory actions of LYR-71 on IFN-gamma-induced STAT-1 phosphorylation and NO production were consistently abolished in the presence of peroxyvanadate, implying another target dependent on protein tyrosine phosphatase. CONCLUSIONS AND IMPLICATIONS: Taken together, LYR-71 could restrain IFN-gamma-induced inflammatory responses through uncoupling the tyrosine phosphorylation of STAT-1, an activation index of JAK-STAT-1 signalling, in macrophages. These results may provide a molecular mechanism underlying anti-inflammatory actions shown by benzoxathiolone derivatives.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Iminas/farmacología , Macrófagos/efectos de los fármacos , Factor de Transcripción STAT1/efectos de los fármacos , Animales , Antiinflamatorios/farmacología , Médula Ósea/metabolismo , Línea Celular , Regulación hacia Abajo/efectos de los fármacos , Ensayo de Inmunoadsorción Enzimática , Inflamación/tratamiento farmacológico , Inflamación/fisiopatología , Interferón gamma/metabolismo , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C3H , Óxido Nítrico/metabolismo , Fosforilación/efectos de los fármacos , Factor de Transcripción STAT1/metabolismo , Tirosina/metabolismo
14.
J Environ Biol ; 30(3): 333-8, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-20120454

RESUMEN

The endogenous gibberellin (GA) and abscisic acid (ABA) contents as an effect of different application times of jasmonic acid (JA) in chard seedlings exposed to salt stress were investigated. Endogenous ABA content was increased by JA treatment after NaCl treatment, rather than after JA application before NaCl treatment. JA application after NaCl treatment caused higher ABA content than treatment with 160 mM NaCl alone. Total gibberellin content decreased after NaCl stress, but NaCl-reduction in total GA contents counteracted by exogenous JA. Total endogenous GA contents were increased in JA treatment after NaCl and were highest at 24 hr of JA application before NaCl exposure. JA treatment promoted the increase of dry weight compared to chard plant exposed to 160 mM NaCl. Thus, JA presumably induces gibberellin biosynthesis showing the promotion of growth and dry weight of chard plants under salt stress.


Asunto(s)
Ácido Abscísico/metabolismo , Beta vulgaris/metabolismo , Ciclopentanos/farmacología , Giberelinas/metabolismo , Oxilipinas/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Cloruro de Sodio/toxicidad , Beta vulgaris/efectos de los fármacos , Beta vulgaris/crecimiento & desarrollo , Salinidad , Plantones/efectos de los fármacos , Plantones/metabolismo , Suelo/análisis , Estrés Fisiológico
15.
Br J Radiol ; 81(965): 413-21, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18283073

RESUMEN

The objective of the study was to evaluate the efficacy of beta-radiation using a rhenium-188-mercaptoacetyltriglycine ((188)Re-MAG(3))-filled balloon for preventing tissue hyperplasia secondary to bare stent placement in a rabbit oesophageal model. Immediately following bare stent placement in 30 rabbits, 10 underwent conventional contrast-filled balloon dilation (control group, Group I), and 20 underwent (188)Re-MAG(3)-filled balloon dilation, with half of these receiving 20 Gy (Group II) and half receiving 40 Gy (Group III) at a 1 mm tissue depth. Diameter percentage stenosis was calculated using oesophagography performed before sacrifice 6 weeks later. Gross and microscopic findings were obtained at both an area of untreated oesophageal tissue and a mid-stent area. Apoptosis and an apoptotic index in the mid-stent area were evaluated in two rabbits from each group. 13 rabbits survived the scheduled 6-week stent placement. Diameter percentage stenosis for Groups II and III was significantly lower than for Group I. The oesophageal mucosa showed nodularity in Group I and smoothness in Groups II and III. Oesophageal mucosal erythema (n = 9) and perforations (n = 10) were observed in Groups II and III only. Mid-stent epithelial layer thickness and muscularis propria destruction differed between the three groups (p<0.05). Apoptosis was increased and the apoptotic index was higher in Groups II and III than in Group I. In conclusion, (188)Re-MAG(3)-filled balloon dilation was effective in preventing tissue hyperplasia secondary to bare stent placement, but at the cost of an increased risk of radiation-induced mucosal inflammation and perforation, in a rabbit oesophageal model. Apoptosis may be the mechanism underlying this irradiation-induced suppression of tissue hyperplasia.


Asunto(s)
Esófago/efectos de la radiación , Radioisótopos/uso terapéutico , Renio/uso terapéutico , Stents , Animales , Cateterismo , Hiperplasia/prevención & control , Oligopéptidos/uso terapéutico , Compuestos Organometálicos/uso terapéutico , Conejos
16.
Phys Rev Lett ; 94(19): 197001, 2005 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-16090198

RESUMEN

We report simultaneous NMR and electrical transport experiments in the pressure range near the boundary of the antiferromagnetic spin density wave (SDW) insulator and the metallic/superconducting (SC) phase in (TMTSF)2PF6. Measurements indicate a tricritical point separating a line of second-order SDW/metal transitions from a line of first-order SDW/metal(SC) transitions with coexistence of macroscopic regions of SDW and metal(SC) order, with little mutual interaction but strong hysteretic effects. NMR results quantify the fraction of each phase.

17.
J Acoust Soc Am ; 117(4 Pt 1): 2078-89, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15898649

RESUMEN

The acoustic attenuation performance of perforated dissipative circular expansion chambers with inlet/outlet extensions is investigated. The eigenvalues and eigenfunctions of the sound field are analytically determined in the extended inlet/outlet circular ducts, upstream/downstream end annular dissipative chambers, and the central perforated dissipative expansion chamber. Utilizing the continuity conditions of velocity/pressure at the interfaces the transmission loss is predicted by a two-dimensional analytical approach. For a specific configuration, such predictions are compared with both experiments and a three-dimensional computational solution based on the substructure boundary element technique, showing a reasonable agreement. The analytical results for the effect of the absorbent resistivity, duct porosity, and geometryon the acoustic attenuation performance are discussed in detail.

18.
J Acoust Soc Am ; 117(2): 725-33, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15759692

RESUMEN

A closed-form, two-dimensional analytical solution is developed to investigate the acoustic performance of a concentric circular Helmholtz resonator lined with fibrous material. The effect of density and the thickness of the fibrous material in the cavity is examined on the resonance frequency and the transmission loss. With the expressions for the eigenvalue and eigenfunction in the cavity, the transmission loss is obtained for a piston-driven model by applying a pressure/velocity matching technique. The results from the analytical methods are compared to the numerical predictions from a three-dimensional boundary element method and the experimental data obtained from an impedance tube setup. It is shown that the acoustic performance of a Helmholtz resonator may be modified considerably by the density and thickness of the fibrous material without changing the cavity dimensions.

20.
Phys Rev Lett ; 91(5): 056601, 2003 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-12906616

RESUMEN

We have measured the thermoelectric signal along the a axis in (TMTSF)2PF6 at 10 kbar as a function of the orientation of the applied magnetic field. Resonantlike Nernst signals were found with a dramatic sign change as the field was rotated through the "Lebed magic angles." The sign change indicates that the electrical current is "locked in" to the magic angle (interchain) directions for field alignment close to, but on either side of, the magic angles. The amplitude of signals near these angles is many orders of magnitude larger than expected from conventional Boltzmann transport theory.

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