Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Opt Express ; 22(12): 14411-24, 2014 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-24977538

RESUMEN

In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

2.
Int J Immunopathol Pharmacol ; 24(2): 345-56, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21658309

RESUMEN

Eugenol and isoeugenol, two components of clover oil, have been reported to possess several biomedical properties, such as anti-inflammatory, antimicrobial and antioxidant effects. This study aims to examine the anti-inflammatory effects of eugenol, isoeugenol and four of their derivatives on expression of inducible nitric oxide synthase (iNOS) activated by lipopolysaccharide (LPS) in mouse macrophages (RAW 264.7), and to investigate molecular mechanisms underlying these effects. We found that two derivatives, eugenolol and glyceryl-isoeugenol, had potent inhibitory effects on LPS-induced upregulation of nitrite levels, iNOS protein and iNOS mRNA. In addition, they both suppressed the release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) induced by LPS. Moreover, they both attenuated the DNA binding of NF-kB and AP-1, phosphorylation of inhibitory kB-alpha (IkB-alpha), and nuclear translocation of p65 protein induced by LPS. Finally, we demonstrated that glyceryl-isoeugenol suppressed the phosphorylation of ERK1/2, JNK and p38 MAPK, whereas eugenolol suppressed the phosphorylation of ERK1/2 and p38 MAPK. Taken together, these results suggest that that eugenolol and glyceryl-isoeugenol suppress LPS-induced iNOS expression by down-regulating NF-kB and AP-1 through inhibition of MAPKs and Akt/IkB-alpha signaling pathways. Thus, this study implies that eugenolol and glyceryl-isoeugenol may provide therapeutic benefits for inflammatory diseases.


Asunto(s)
Antiinflamatorios/farmacología , Endotoxinas/farmacología , Eugenol/farmacología , Glicerol/farmacología , Proteínas I-kappa B/metabolismo , Macrófagos/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Transcripción AP-1/metabolismo , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Eugenol/análogos & derivados , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Mediadores de Inflamación/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/enzimología , Macrófagos/inmunología , Ratones , Inhibidor NF-kappaB alfa , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Fosforilación , ARN Mensajero/metabolismo , Factor de Transcripción ReIA/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
3.
Nanotechnology ; 21(13): 134008, 2010 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-20208118

RESUMEN

Pt contact on p-Si nanowires (NWs) using Ga-ion-induced deposition by a focused ion beam was formed with a specific contact resistance (rho(c)) of 1.54 x 10(-6) Omega cm(2). Ohmic behavior is caused by Ga-ion-induced amorphization of Si NWs underneath the Pt contact. A very low Schottky barrier height associated with interface states raised from Pt-amorphized Si junction and with an image force induced by the applied bias can be implemented to elucidate ultralow rho(c). The value of rho(c) lower than that of any known contact to Si NWs demonstrates a practical method for integrating NWs in devices and circuits.

4.
J Agric Food Chem ; 54(18): 6790-9, 2006 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-16939341

RESUMEN

The qualitative and quantitative characteristics of soil organic carbon (SOC) and related humic acids (HAs) extracted from the soils of field plots were investigated after 8 years of annual paddy (Oryza sativa L.) and upland maize (Zea mays L.) rotation with various fertilizations. Seven fertilization treatments were selected: Ck (no inputs); Chem (chemical fertilizer of NPK); Comp (swine compost); Comp + 33% of Chem N rate; Comp + 67% of Chem N rate; GM (legume green manure) + 33% of Chem N rate; and peat + 33% of Chem N rate. Organic and inorganic nitrogen inputs of six treatments were equivalent with respect of nitrogen content, but Comp, GM, and peat treatments were complemented with various amounts of inorganic N. After harvest of the eighth paddy crop, surface soil samples collected from the plots were subjected to soil characterizations and extraction of humic substances, which were used for chemical, spectroscopic (FTIR, 13C NMR, ESR, X-ray diffractometry), delta13C, and 14C dating analyses. The yields of HAs extracted from the seven treatments were significantly different. Treatment containing persistent organic compound such as the peat + 33% N treatment increased the humification process in topsoils and produced higher yield of HA. Spectroscopic analyses revealed that fertilization treatments changed the functional groups, alkyl C, crystalline characteristics, and delta13C ratios of HAs and turnover rate of SOC considerably. The SOC of the peat + 33% N treatment had the highest mean residence time of 3100 years. Various fertilizer treatments are correlated with turnover rate of SOC and related HAs, which are associated with concerned carbon sequestration as well as mitigation of CO2 emission in the soil environment.


Asunto(s)
Agricultura/métodos , Carbono/análisis , Fertilizantes , Sustancias Húmicas/análisis , Oryza/crecimiento & desarrollo , Suelo/análisis , Nitrógeno/análisis , Zea mays/crecimiento & desarrollo
5.
Trends Endocrinol Metab ; 9(3): 103-12, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18406250

RESUMEN

The thyroid hormone receptor genes, TRalpha and TRbeta, differ in developmental expression and tissue distribution. TRbeta knockout mice have goiter, elevated thyroid hormone and TSH levels, and a functional auditory defect. In contrast, mice with TRalpha 1/alpha2 inactivation have thyroid hypoplasia, low serum thyroid hormone levels, growth arrest and delayed small intestine maturation. Mice with selective TRalpha1 inactivation have apparent normal growth and development, but have bradycardia and reduced body temperature. The dramatic differences between these mice with TRbeta and TRalpha gene inactivations indicate the differential function of these genes. The influence of these gene inactivations on thyroid-stimulating hormone regulation is central to the resulting phenotypes.

6.
Endocrinology ; 136(2): 421-30, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7835272

RESUMEN

Retinoid-X receptor (RXR) forms heterodimers with thyroid hormone receptor (TR) and significantly enhances binding to thyroid hormone response elements (TREs). Expression of RXR in a transient transfection assay augments the T3 response, but the influences of the specific cell line and TRE used have not been systematically studied. We determined RXR alpha and -beta augmentation of the TR alpha-mediated T3 response in transient transfection assays of COS, JEG, and mouse embryonic stem (ES) cell lines for a series of eight wild-type thyroid hormone (T3) and retinoic acid response elements (previously shown to bind TR). RXR augmented T3-induced expression in COS and ES cells (1.5- to 4-fold greater expression with added RXR compared to TR alone), but had minimal effect on augmentation of response in JEG cells. For most elements studied there was a proportional augmentation of basal and T3-stimulated expression. TREs from rat GH and laminin-B1, however, had relatively higher levels of T3-induced expression as a result of RXR cotransfection (T3 induction ratios increased 2-fold or greater). Previous characterization of these elements demonstrates that they contain more than two hexameric binding domains, all of which can simultaneously bind TR. The influence of endogenous RXR expression in a cell line on RXR augmentation of the T3 response was determined. RXR alpha and -beta messenger RNA (mRNA) expression was quantitated by Northern blot in each cell line. COS and JEG cells expressed almost exclusively RXR alpha mRNA, although expression was almost 2-fold higher in JEG compared to COS cells (12 +/- 2.5 vs. 6.8 +/- 0.5 density units relative to actin; mean +/- SE; P < 0.05). ES cells expressed only RXR beta mRNA, but at a very low level (0.4 +/- 0.1). Nuclear extracts prepared from JEG and COS cells augmented TR binding proportional to the endogenous RXR mRNA expression, and the heterodimer band was supershifted by the addition of antibody to RXR alpha. Nuclear extracts from ES cells had no detectable TR heterodimer binding to a range of response elements. RXR augmentation of the T3 response differs among cell lines and is greater in those with reduced endogenous RXR. Furthermore, the functional augmentation of the T3 response ratio by RXR is likely to require additional sequences contained in only a subset of elements in which RXR augments TR binding.


Asunto(s)
Receptores de Ácido Retinoico/metabolismo , Receptores de Hormona Tiroidea/metabolismo , Hormonas Tiroideas/metabolismo , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Northern Blotting , Línea Celular , Núcleo Celular/metabolismo , Ratones , Datos de Secuencia Molecular , ARN Mensajero/análisis , Ensayo de Unión Radioligante , Receptores de Ácido Retinoico/genética , Receptores de Hormona Tiroidea/genética , Receptores X Retinoide , Alineación de Secuencia , Células Madre , Factores de Transcripción/genética , Transfección
7.
Radiother Oncol ; 43(1): 75-9, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9165140

RESUMEN

BACKGROUND AND PURPOSE: Anorexia is a common problem in cancer patients who receive radiotherapy. In this current study, we attempt to determine the effect of megestrol acetate and prepulsid on appetite and nutritional improvement in patients with head and neck cancers undergoing radiotherapy. MATERIALS AND METHODS: One hundred twenty-nine consecutive patients with head and neck cancers treated between July 1993 and June 1994 were prospectively randomized to receive either megestrol acetate, 40 mg qid (megace group), prepulsid, 5 mg tid (cisapride group), or a placebo treatment (control group) during radiotherapy. Before radiotherapy, body weight (kg), appetite score, performance status, biochemical parameters and hematological parameters were evaluated, and the above-noted clinical and biochemical parameters were assessed and recorded every other week. All patients received 6- 10 MV X-rays or Co-60 gamma-ray to head and neck region for a full course of radiotherapy, 61.2-75.6 Gy/7-9 weeks. RESULTS: Forty-eight patients were enrolled in the megace group, 41 patients in the cisapride group, and 40 patients in the control group. At the 2nd, 4th, 6th and 8th week, as the radiation dose escalated, the megace group had significantly less body weight loss than did the cisapride and control groups (P = 0.045, 0.024, 0.006, 0.003, respectively). The appetite scores of the megace group were significantly higher than those of the cisapride and control groups (P = 0.0001). However, there were no statistically significant differences in the change of albumin level among these three groups at the 2nd, 4th, 6th and 8th week (P > 0.05, respectively). CONCLUSIONS: Megestrol acetate can significantly decrease the degree of body weight loss, and can prevent the deterioration of appetite in patients with head and neck cancers receiving radiotherapy. However, prepulsid lacks the above-mentioned clinical benefits.


Asunto(s)
Estimulantes del Apetito/uso terapéutico , Neoplasias de Cabeza y Cuello/radioterapia , Acetato de Megestrol/uso terapéutico , Piperidinas/uso terapéutico , Adulto , Anciano , Cisaprida , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fenómenos Fisiológicos de la Nutrición , Estudios Prospectivos , Pérdida de Peso/efectos de los fármacos
8.
Biosens Bioelectron ; 19(11): 1465-71, 2004 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-15093218

RESUMEN

The detection performance of conventional surface plasmon resonance (SPR) biosensors is limited to a 1 pg/mm(2) surface coverage of biomolecules, and consequently, such sensors struggle to detect the interaction of small molecules in low concentrations. The present study is attempted to propose the use of a novel SPR biosensor with Au nanoclusters embedded in a dielectric film to achieve a 10-fold improvement in the resolution performance. A co-sputtering method utilizing a multi-target sputtering system is used to fabricate the present dielectric films (SiO(2)) with embedded Au nanoclusters. It is shown that the sensitivity of the developed SPR biosensor can be improved by adjusting the size and volume fraction of the embedded Au nanoclusters in order to control the surface plasmon effect. The present gas detection and DNA hybridization experimental results confirm that the proposed Au nanocluster-enhanced SPR biosensor provides the potential to achieve an ultrahigh-resolution detection performance of approximately 0.1 pg/mm(2) surface coverage of biomolecules.


Asunto(s)
Técnicas Biosensibles/instrumentación , Plata , Resonancia por Plasmón de Superficie/instrumentación , Argón/química , Microscopía Electrónica , Microscopía Electrónica de Transmisión , Nanotecnología , Nitrógeno/química
9.
J Biotechnol ; 108(1): 1-9, 2004 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-14741764

RESUMEN

This paper provides a method for producing a novel type coded micro-carrier. A simple and cost effective solution for bio-molecule applications was developed. Application relevant items such as manufacture process, biospecific interaction, and analysis method are discussed. For low cost fabrication, the use of LIGA-like process is suggested. LIGA-like process is used as a dry patterning process in which an intense beam of light from an excimer laser is used to pattern a material directly. This process has found extensive application in the microelectronics industry for patterning of polymer materials. The use of LIGA-like techniques offers two attractive features: first, we can cut the polymer into many tiny micro-carriers with micrometer precision. Second, LIGA-like process allows to encode with high precision spatial information onto the micro-carrier that can be used in the identification of the bio-molecule. This paper gives a description of the basic idea, describes the fabrication of the novel micro-carrier that we called "coded micro-carrier," and of the image processing algorithms used for the analysis of bio-molecules. This study also provides a test method for identifying a bio-molecule, which includes mixing several coded micro-carriers with the hybridized unknown bio-molecules; and identifying the codes on the micro-carrier via image recognition system. The numbers and types of the known micro-carrier can be flexibly adjusted according to the number of tested bio-molecules.


Asunto(s)
Microquímica/métodos , Análisis por Matrices de Proteínas , Animales , Diseño de Equipo , Procesamiento de Imagen Asistido por Computador , Microquímica/instrumentación , Modelos Biológicos , Propiedades de Superficie
10.
Anticancer Res ; 20(2B): 1221-8, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10810425

RESUMEN

BACKGROUND: This study investigates the cell proliferation and the expression of p53 protein in Helicobacter pylori (H. pylori)-associated gastritis and assesses the effect of bacterial eradication on these epithelial factors. MATERIAL AND METHODS: Seventy-nine patients with H. pylori-associated gastritis were randomized into the control group (n = 38) and anti-H. pylori group (n = 41). Each patient received endoscopic examinations with gastric biopsy before and 8 weeks after the treatment. The specimens from gastric antrum were immunostained for monoclonal antibodies against the proliferating cell nuclear antigen (PCNA) and p53 protein. RESULTS: In the control group, the total labeling index (L.I.) of PCNA and the positive index (P.I.) of p53 in the whole foveolar epithelium were unchanged after treatment. In the anti-H. pylori group, 35 of 41 cases (85.3%) achieved eradication of H. pylori. Amongst the H. pylori-eradicated cases, the total L.I. of PCNA in the whole foveolar epithelium did not meaningfully alter after H. pylori elimination (p > 0.05). However, a significant reduction of L.I. was observed in the middle compartments of the gastric pits (before vs. after treatment: 14.0 vs. 7.3, p < 0.05). With regard to the p53 expression, the P.I.s were significantly decreased in the whole foveolar epithelium (before vs. after treatment: 0.57 vs. 0.17, p < 0.05) and in each compartment of the gastric pits (before vs. after treatment: [upper compartment]: 0.34 vs. 0.15, p < 0.05; [middle compartment]: 0.67 vs. 0.23, p < 0.05; [lower compartment]: 0.71 vs. 0.20, p < 0.05) after eradication of H. pylori. CONCLUSIONS: Bacterial eradication reverses the hyperproliferating status of the foveolar epithelium in patients with H. pylori gastritis and leads to a decrease in p53 accumulation in the epithelial cells.


Asunto(s)
Quimioterapia Combinada/uso terapéutico , Gastritis/tratamiento farmacológico , Gastritis/patología , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/patología , Helicobacter pylori , Metronidazol/uso terapéutico , Omeprazol/análogos & derivados , Tetraciclina/uso terapéutico , Proteína p53 Supresora de Tumor/análisis , 2-Piridinilmetilsulfinilbencimidazoles , Antiácidos/uso terapéutico , Antibacterianos/uso terapéutico , Atrofia , División Celular , Femenino , Gastritis/microbiología , Humanos , Inmunohistoquímica , Lansoprazol , Masculino , Metaplasia , Persona de Mediana Edad , Omeprazol/uso terapéutico , Compuestos Organometálicos/uso terapéutico , Antígeno Nuclear de Célula en Proliferación/análisis
11.
Nucl Med Commun ; 24(7): 819-24, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12813201

RESUMEN

Our objective was to examine and correlate 99mTc-diethylenetriaminopentaacetic acid (99mTc-DTPA) ventilation and 99mTc-macroaggregated albumin (99mTc-MAA) perfusion (V/Q) lung scans with spirometry in asymptomatic asthmatic children. We evaluated 89 subjects (age range, 6-15 years; mean age, 9.4 years), all with at least 70% predicted forced expiratory volume in 1 s (FEV(1)). There were four V/Q scan patterns: normal in 38 (42.7%), inhomogeneous ventilation in 11 (12.4%), matched defects in 25 (28.3%) and mismatched perfusion defects in 13 (14.6%). The maximal mid-expiratory flow rate (MMEF) of the normal scan group was significantly different from that in the other groups. The MMEF of the inhomogeneous group was significantly different from that in the matched defect group and the mismatched perfusion defect group. No other significant differences in spirometric indices were found. In two children with perfusion defects, pulmonary arteriograms demonstrated no obstructive lesions. In conclusion, lung scans provide diagnostic information in asymptomatic asthmatic children, even when they are uncooperative. Abnormal scans are common in these children and are significantly correlated with reduced MMEF (% predicted), reflecting small airway flow obstruction. The pathophysiology of V/Q defects in asymptomatic asthmatic children warrants further investigation.


Asunto(s)
Asma/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Pruebas de Función Respiratoria/métodos , Agregado de Albúmina Marcado con Tecnecio Tc 99m , Pentetato de Tecnecio Tc 99m , Administración por Inhalación , Adolescente , Asma/diagnóstico , Niño , Volumen Espiratorio Forzado , Humanos , Técnicas In Vitro , Inyecciones Intravenosas , Pulmón/irrigación sanguínea , Masculino , Cintigrafía , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Espirometría/métodos , Agregado de Albúmina Marcado con Tecnecio Tc 99m/administración & dosificación , Pentetato de Tecnecio Tc 99m/administración & dosificación , Relación Ventilacion-Perfusión
12.
Environ Pollut ; 114(1): 119-27, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11444000

RESUMEN

This research was conducted to study the influence of composting on the concentrations, water solubility, and phase association of Cu, Mn, and Zn from swine (Sus domesticus) feces. Composting of separated swine manure was performed in two piles for 122 days. The metal concentrations increased rapidly during the first 49 days and leveled off thereafter. All metal concentrations increased approximately 2.7-fold in the final compost due to decomposition of organic matter. A sequential extraction protocol was used to evaluate the humification process and partition metals into water-soluble, exchangeable, organically complexed, organically bound, solid particulate, and residual fractions. Temporal changes in the water-soluble fractions of Cu, Mn, and Zn were reflected by water-soluble organic C concentrations, which rapidly increased to a maximum at Day 18 and declined thereafter. An increase in the humic acid/fulvic acid ratio in Na4P2O7 or NaOH extracts at various stages of composting represented the humification process. During composting, the major portions of Cu, Mn, and Zn were in the organically-bound, solid particulate, and organically complexed fractions, respectively. Metal distributions in different chemical fractions were generally independent of composting age and, thus, independent of respective total metal concentrations in the composts.


Asunto(s)
Conservación de los Recursos Naturales , Cobre/metabolismo , Manganeso/metabolismo , Estiércol , Zinc/metabolismo , Animales , Fenómenos Químicos , Química Física , Cobre/química , Contaminación Ambiental/prevención & control , Manganeso/química , Compuestos Orgánicos/metabolismo , Contaminantes del Suelo/análisis , Solubilidad , Porcinos , Zinc/química
13.
Comput Med Imaging Graph ; 25(6): 477-82, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11679209

RESUMEN

The purpose of this investigation is to establish a practical method to predict and create surface a profile of bone defects by a well-trained 3-D orthogonal neural network. First, the coordinates of the skeletal positions around the boundary of bone defects are input into the 3-D orthogonal neural network to train it to learn the scattering characteristic. The 3-D orthogonal neural network avoids local minima and converges rapidly. After the neural network has been well trained, the mathematic model of the bone defect surface is generated, and the pixel positions are derived. Herein, to verify its performance the proposed method is applied on a patient with a craniofacial defect.


Asunto(s)
Imagenología Tridimensional/métodos , Maxilar/anatomía & histología , Modelos Anatómicos , Redes Neurales de la Computación , Cráneo/anatomía & histología , Humanos , Maxilar/anomalías , Maxilar/cirugía , Cráneo/anomalías , Cráneo/cirugía , Tomografía Computarizada por Rayos X/métodos
14.
J Formos Med Assoc ; 100(9): 613-9, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11695277

RESUMEN

BACKGROUND AND PURPOSE: During the period from August 1994 to October 1998, a total of 19 isolates of Exophiala jeanselmei were recovered from 17 patients with various underlying thoracic diseases treated at National Taiwan University Hospital. The purpose of this study was to describe the clinical characteristics of these patients and to determine the microbiologic relatedness of the E. jeanselmei. METHODS: Of the 19 isolates, 11 from nine patients were preserved and were identified based on their biotypes as determined by the API ID32C System, their cellular fatty acid profiles by gas-liquid chromatography, their antibiotypes to five antifungal agents by the E-test, and their random amplified polymorphic DNA (RAPD) patterns by arbitrarily primed PCR. Extensive environmental surveillance cultures and cultures from the skin of eight patients and hands of one physician were also performed. RESULTS: One of the 17 patients had E. jeanselmei isolated from cutaneous phaeohyphomycosis (3 isolates), and the other 16 patients had isolations from pleural effusion specimens (15 isolates) or lung mass (1 isolate) following sonography-guided aspiration. The latter 16 patients had no clinical or pathologic evidence of fungal infection. Isolates (clone 1) from aspirated specimens had identical biotypes, antibiotypes, and RAPD patterns, which were different from those of the three isolates (clone 2) from the patient with a cutaneous lesion. All specimens from environmental sources, patients' skin, and the hands of the physician were negative for E. jeanselmei. CONCLUSION: This series of patients demonstrates the difficulty in identifying the sources of a nosocomial pseudoinfection due to this slow-growing microorganism when isolated from pleural effusion specimens.


Asunto(s)
Infección Hospitalaria/microbiología , Exophiala/aislamiento & purificación , Micosis/microbiología , Enfermedades Torácicas/diagnóstico por imagen , Adulto , Anciano , Biopsia con Aguja , Exophiala/clasificación , Exophiala/efectos de los fármacos , Ácidos Grasos/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Técnica del ADN Polimorfo Amplificado Aleatorio , Enfermedades Torácicas/complicaciones , Ultrasonografía
15.
J Med Eng Technol ; 24(6): 262-6, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11315653

RESUMEN

Traditionally, the orthopaedist, according to their past experience, reconstructs damaged area while the operation is in progress. This may prolong the operation and cause the wound to become infected. Most importantly it is difficult to precisely match the skeletal defect. A well-disciplined network of prediction re-fabricates the damaged area through automation. This research is based on the CT image file, which is the product of X-ray computed tomography (CT), and computes the skeletal positions around the damaged area through image processing and boundary detection. The skeletal positions are inputted into the orthogonal neural network and discipline the network so that it possesses the scattering characteristic of bone. The network then calculates skeletal positions in the damaged area and revises the former CT image file to rebuild a 3D model. Accordingly, in comparison with a manual sketch, the orthogonal neural network forecast is more geometrically precise. Moreover, the forecast satisfies the second order derivative, which is a continuous function, and the edge of the fabricated bone is therefore kept smoother.


Asunto(s)
Maxilar/cirugía , Redes Neurales de la Computación , Procedimientos Ortopédicos/métodos , Cráneo/cirugía , Ingeniería Biomédica , Humanos , Maxilar/diagnóstico por imagen , Modelos Anatómicos , Procedimientos Ortopédicos/estadística & datos numéricos , Cráneo/anatomía & histología , Cráneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X
16.
J Med Eng Technol ; 25(4): 173-7, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11601445

RESUMEN

Image segmentation is the partition of an image into a set of non-overlapping regions that comprise the entire image. The image is decomposed into meaningful parts, which are uniform with respect to certain characteristics, such as grey level or texture. This study presents a novel methodology to evaluate ultrasound image segmentation algorithms. The sonographic features can differentiate between various sized malignant and benign breast tumours. The clinical experiment can determine whether a tumour is benign or not, based on contour, shape, echogenicity and echo texture. Further study of the standardized sonographic features, especially the tumour contour and shape, will improve the positive predictive value and accuracy rate in breast tumour detection. The effectiveness of using this methodology is illustrated by evaluating image segmentation on breast ultrasound images. Via definite segmentation, the appreciated tumour shape and contour can be ascertained. Furthermore, this method can enhance the ability of ultrasound to distinguish between benign and malignant breast lesions.


Asunto(s)
Algoritmos , Neoplasias de la Mama/diagnóstico por imagen , Carcinoma Ductal de Mama/diagnóstico por imagen , Fibroadenoma/diagnóstico por imagen , Enfermedad Fibroquística de la Mama/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Ultrasonografía Mamaria , Diagnóstico Diferencial , Femenino , Humanos , Oportunidad Relativa
17.
Oncogene ; 30(17): 2077-85, 2011 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-21170084

RESUMEN

The polycomb group family protein BMI-1 is overexpressed by and functions as an oncogene in many different human cancers. We have previously shown that BMI-1 promotes the tumorigenicity of Ewing sarcoma family tumors (ESFTs) and that this is mediated independently of CDKN2A repression. In this study, we have discovered that high levels of BMI-1 confer resistance to contact inhibition in ESFT cells. Using stable retroviral transduction, we evaluated the consequences of BMI-1 knockdown on the growth of CDKN2A wild-type and mutant ESFT cells in subconfluent and confluent conditions. Although knockdown of BMI-1 had no effect on proliferation in low-density cultures, at high cell densities it resulted in cell cycle arrest and death. The normal cell contact inhibition response is mediated, in large part, by the recently described Hippo pathway which functions to inhibit cell proliferation and promote cell death by inactivating the Yes-Associated Protein (YAP). Significantly, we found that YAP levels, activity and expression did not diminish in confluent ESFT cells that expressed high levels of BMI-1. In contrast, YAP expression and nuclear localization were reduced in confluent BMI-1 knockdown cells suggesting that silencing of BMI-1 restored contact inhibition by restoring normal activation of the Hippo-YAP growth-suppressor pathway. Importantly, knockdown of YAP in ESFT cells resulted in profound inhibition of cell proliferation and anchorage-independent colony formation suggesting that stabilization and continued expression of YAP is critical for ESFT growth and tumorigenicity. Together, these studies reveal a previously unrecognized link between BMI-1, contact inhibition and the Hippo-YAP pathway and suggest that resistance to contact inhibition in BMI-1 overexpressing cancer cells may be in part a result of Hippo inhibition and aberrant stabilization of YAP.


Asunto(s)
Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Inhibición de Contacto , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Represoras/metabolismo , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patología , Factores de Transcripción/metabolismo , Secuencia de Bases , Neoplasias Óseas/genética , Proteínas de Ciclo Celular , Línea Celular Tumoral , Humanos , Proteínas Nucleares/genética , Oncogenes/genética , Complejo Represivo Polycomb 1 , Estabilidad Proteica , Sarcoma de Ewing/genética , Transducción de Señal , Factores de Transcripción/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA