RESUMEN
BACKGROUND AND PURPOSE: ADC provides a measure of water molecule diffusion in tissue. The aim of this study was to evaluate whether the fractional change in ADC during therapy can be used as a valid predictive indicator of treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy. MATERIALS AND METHODS: Forty patients underwent DWI at pretreatment and 3 weeks after the start of treatment. The pretreatment ADC, fractional change in ADC, tumor regression rate, and other clinical variables were compared with locoregional control and locoregional failure and were analyzed by using logistic regression analysis and receiver operating characteristic analysis. Furthermore, progression-free survival curves divided by the corresponding threshold value were compared by means of the log-rank test. RESULTS: The fractional change in ADCprimary, the fractional change in ADCnode, primary tumor volume, nodal volume, tumor regression ratenode, N stage, and tumor location revealed significant differences between locoregional failure and locoregional control (P < .05). In univariate analysis, the fractional change in ADCprimary, fractional change in ADCnode, tumor regression ratenode, N stage, and tumor location showed significant association with locoregional control (P < .05). In multivariate analysis, however, only the fractional change in ADCprimary was identified as a significant and independent predictor of locoregional control (P = .04). A threshold fractional change in ADCprimary of 0.24 revealed a sensitivity of 100%, specificity of 78.7%, and overall accuracy of 84.8% for the prediction of locoregional control. Progression-free survival of the 2 groups divided by the fractional change in ADCprimary at 0.24 showed a significant difference (P < .05). CONCLUSIONS: The results suggest that the fractional change in ADCprimary is a valid imaging biomarker for predicting treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy.
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Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia , Quimioradioterapia/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias de Cabeza y Cuello/diagnóstico , Neoplasias de Cabeza y Cuello/terapia , Evaluación de Resultado en la Atención de Salud/métodos , Adulto , Anciano , Biomarcadores , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Carcinoma de Células Escamosas de Cabeza y Cuello , Resultado del TratamientoRESUMEN
The FLC gene product is an inhibitor of flowering in Arabidopsis. FLC homologs in Brassica species are thought to control vernalization. We cloned four FLC homologs (BoFLCs) from Brassica oleracea. Three of these, BoFLC1, BoFLC3 and BoFLC5, have been previously characterized. The fourth novel sequence displayed 98% sequence homology to the previously identified gene BoFLC4, but also showed 91% homology to BrFLC2 from Brassica rapa. Phylogenetic analysis showed that this clone belongs to the FLC2 clade. Therefore, we designated this gene BoFLC2. Based on the segregation of RFLP, SRAP, CAPS, SSR and AFLP loci, a detailed linkage map of B. oleracea was constructed in the F(2) progeny obtained from a cross of B. oleracea cv. Green Comet (broccoli; non-vernalization type) and B. oleracea cv. Reiho (cabbage; vernalization type), which covered 540 cM, 9 major linkage groups. Six quantitative trait loci (QTL) controlling flowering time were detected. BoFLC1, BoFLC3 and BoFLC5 were not linked to the QTLs controlling flowering time. However, the largest QTL effect was located in the region where BoFLC2 was mapped. Genotyping of F(2 )plants at the BoFLC2 locus showed that most of the early flowering plants were homozygotes of BoFLC-GC, whereas most of the late- and non-flowering plants were homozygotes of BoFLC-Rei. The BoFLC2 homologs present in plants of the non-vernalization type were non-functional, due to a frameshift in exon 4. Moreover, duplications and deletions of BoFLC2 were detected in broccoli and a rapid cycling line, respectively. These results suggest that BoFLC2 contributes to the control of flowering time in B. oleracea.
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Brassica/genética , Flores/fisiología , Filogenia , Polimorfismo Genético , Sitios de Carácter Cuantitativo , Proteínas de Arabidopsis/genética , Secuencia de Bases , Southern Blotting , Brassica/fisiología , Mapeo Cromosómico , Clonación Molecular , Análisis por Conglomerados , Cartilla de ADN , Flores/genética , Componentes del Gen , Proteínas de Dominio MADS/genética , Datos de Secuencia Molecular , Polimorfismo de Longitud del Fragmento de Restricción , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Homología de SecuenciaRESUMEN
Association between the RAPD markers and the resistance to race 4 of the black rot causative agent was studied in Brassica rapa L. Experiments were carried out using doubled haploid lines, obtained via crosses between the race 4-susceptible fodder turnip and resistant pak-choi, and the F2 progeny of the crosses between the doubled haploid lines with contrasting resistance. The WE(22)980 RAPD marker inherited from the pak-choi and associated with the clubroot susceptibility was also linked to the locus responsible for the resistance to race 4 of Xanthomonas campestris pv. campestris. The two other RAPD markers were linked to susceptibility to black rot. Simultaneous association of the same DNA markers with the resistance/susceptibility to two different obligate pathogens favored the hypothesis on cluster organization of the resistance genes in plants. The markers described can be used in plant breeding and in further investigation of the genetic bases of resistance in plants.
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Brassica/genética , Mapeo Cromosómico , Ligamiento Genético , Marcadores Genéticos , Xanthomonas campestris/patogenicidad , Secuencia de Bases , Brassica/microbiología , Cartilla de ADN , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
OBJECTIVE: We describe four cases of subchondral osteonecrosis of the vertebral body that occurred after percutaneous laser diskectomy. Follow-up MR imaging after laser intervention showed abnormal findings in the vertebral body immediately adjacent to the site of diskectomy that are consistent with subchondral osteonecrosis. CONCLUSION: MR imaging features of this complication include a wedge-shaped low signal intensity on T1-weighted images, high and low signal intensities on T2-weighted images, and a contrast-enhanced area corresponding to high signal intensity on T2-weighted images. Possible causative mechanisms include thermal injury and photoacoustic shock.
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Discectomía Percutánea , Desplazamiento del Disco Intervertebral/cirugía , Terapia por Láser , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Osteonecrosis/diagnóstico , Complicaciones Posoperatorias/diagnóstico , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Humanos , Desplazamiento del Disco Intervertebral/diagnóstico , Vértebras Lumbares/patología , Masculino , Persona de Mediana EdadRESUMEN
PURPOSE: The purpose of this study was to evaluate the effectiveness of MR sialography of the parotid gland ducts in the diagnosis and staging of Sjögren syndrome. METHODS: MR imaging was performed on a 1.5-T unit with a neck phased-array coil. MR sialographic source images were obtained using a heavily T2-weighted fast spin-echo sequence with spectral fat suppression. All images were analyzed on the basis of maximum intensity projection reconstruction. Five healthy control subjects and 51 patients with definite Sjögren syndrome (43 with primary disease and eight with secondary disease) were examined with MR sialography. A labial gland biopsy was performed in all patients and histopathologic grading was done by means of focal scores. The findings of MR sialography were compared with the results of labial gland biopsy to determine the effectiveness of the technique in the diagnosis and staging of Sjögren syndrome. RESULTS: In all five control subjects, the main duct and the primary branching ducts of the parotid glands were clearly visible on MR sialographic images. In patients with Sjögren syndrome, a punctate, globular, cavitary, or destructive appearance was well seen within the parotid glands. Findings obtained at MR sialography correlated well with the results of labial gland biopsy. CONCLUSION: MR sialography has the potential to produce diagnostic findings in the parotid gland ducts of patients with Sjögren syndrome. Our results suggest that this method will augment and possibly replace X-ray sialography.
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Imagen por Resonancia Magnética , Glándula Parótida/patología , Conductos Salivales/patología , Síndrome de Sjögren/patología , Adolescente , Adulto , Anciano , Biopsia , Estudios de Evaluación como Asunto , Femenino , Humanos , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador , Labio/patología , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Glándulas Salivales Menores/patología , SialografíaRESUMEN
Thin-section, three-dimensional (3D) gradient-echo magnetic resonance imaging of the coronary arteries was performed without and with retrospective respiratory gating in 12 healthy volunteers and one patient. In all examinations, results were improved with gating. In five of seven volunteer examinations, coronary artery delineation on images reconstructed by using the least-squares method for motion detection with navigator echoes was found to be equal to that obtained by using edge detection. Images in five other volunteers covered the entire heart with multiple overlapping 3D slabs. The arteries were segmented from the background and could be viewed from any orientation. The lengths of contiguously visible vessels were as follows: left main coronary artery, 11.5 mm +/- 0.4 (mean +/- standard deviation); left anterior descending branch, 115.9 mm +/- 19.7; left circumflex branch, 97.2 mm +/- 12.5; and right coronary artery, 125.9 mm +/- 18.8. This respiratory gating technique clearly improved depiction of the coronary arteries.
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Vasos Coronarios/anatomía & histología , Angiografía por Resonancia Magnética/métodos , Respiración , Adulto , Femenino , Humanos , Análisis de los Mínimos Cuadrados , Masculino , MovimientoRESUMEN
OBJECTIVE: The MR findings of two cases of subperiosteal hematoma of the orbit are described. MATERIALS AND METHODS: We present two cases of subperiosteal hematoma of the orbit following minor head trauma, the first presenting with chronic progressive exophthalmos and the second with acute proptosis. RESULTS: Both cases showed a well-defined biconvex mass with a curvilinear hypointense band in the superior portion of the orbit. In Case 1 chronic hematoma demonstrated high signal on both T1- and T2-weighted imaging, and in Case 2 acute hematoma displayed intermediate signal on T1-weighted imaging and high signal on T2-weighted imaging. Follow-up MRI in Case 2 demonstrated the typical signal changes from acute to subacute hematoma. CONCLUSION: Subperiosteal hematoma has a characteristic appearance on MRI which is virtually diagnostic. In proper clinical settings MRI is the modality of choice for the detection and characterization of this hematoma.