RESUMEN
While retaining its lamellar liquid crystal phase, K4Nb6O17 nanosheets were used as a template to sandwich and stabilize an alkylpoly(ethylene oxide) nonionic surfactant-water system showing monodomain (lamella) formation within the inorganic niobate sheets that appears to be not dependent on the surfactant liquid crystalline state in solution but more its concentration.
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Cristales Líquidos/química , Nanoestructuras , Niobio/química , Compuestos de Potasio/química , Tensoactivos/químicaRESUMEN
Curcuma or Siam tulip (Curcuma alismatifolia Gagnep.) is an ornamental flowering plant with two underground storage organs, rhizomes and storage roots. Characteristics of N and C assimilation and transport in curcuma were investigated. The plants were treated with (15)NH(4) (+) + (15)NO(3) (-) and (13)CO(2) at 10, 13 or 21 weeks after planting. Plants were sampled at several stages up to 32 weeks. The C stored in old storage roots was used rapidly during the first 10 weeks; after which N stored in old rhizomes and old storage roots were used. The daily gain in C depending on photosynthesis was remarkably high between 10 and 21 weeks. However, the daily gain in N was relatively constant throughout the growth period. The (15)N absorbed at 10 weeks was initially accumulated in leaves and roots, but some was transported to flowering organs at 13 weeks. At harvest, 41% of (15)N was recovered in new rhizomes and 17% in new storage roots. After (13)CO(2) exposure at 10 and 13 weeks, the distribution of (13)C among organs was relatively constant in subsequent stages. When given (13)CO(2) at 21 weeks, a large amount of labelled C was recovered in new storage roots and new rhizomes at harvest. Both new rhizomes and new storage roots stored N and C, however, rhizomes played a more important role in supplying N, while storage roots provided C.
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Carbono/metabolismo , Curcuma/metabolismo , Nitrógeno/metabolismo , Dióxido de Carbono/metabolismo , Isótopos de Carbono/metabolismo , Curcuma/crecimiento & desarrollo , Isótopos de Nitrógeno/metabolismo , Fotosíntesis , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismoRESUMEN
BACKGROUND: Pleomorphic adenoma of the salivary gland (PA) is essentially a benign neoplasm. However, patients with recurrent PA are difficult to manage. There are rare reports on useful immunohistochemical markers to detect a high risk of recurrence when the primary lesions are resected. AIMS: To find a new marker to predict the recurrence of PA. METHODS: Primary lesions of PA were collected from nine patients showing subsequent recurrence and from 40 patients without recurrence during at least 10 years of follow up of the disease. Paraffin wax embedded tumour samples of the two groups were examined for the expression profiles of MUC1 (differentially glycosylated forms), MUC2, MUC4, MUC5AC, and MUC6 using immunohistochemistry. Several clinicopathological factors were also examined. RESULTS: In univariate analysis of the factors examined, MUC1/DF3 high expression (more than 30% of the neoplastic cells stained) in the primary lesions was seen more frequently in patients with recurrence (four of nine) than in those without recurrence (three of 40; p = 0.011). Larger tumour size (more than 3.0 cm) of the primary PA was also a significant (p = 0.035) risk factor for the recurrence of PA. In multivariate analysis, only high expression of MUC1/DF3 was found to be a significant independent risk factor for the recurrence of PA (p = 0.021). CONCLUSIONS: Expression of MUC1/DF3 in PA is a useful marker to predict its recurrence. Those patients with PA showing positive MUC1/DF3 expression should be followed up carefully.
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Adenoma Pleomórfico/química , Biomarcadores de Tumor/análisis , Mucina-1/análisis , Recurrencia Local de Neoplasia/química , Neoplasias de las Glándulas Salivales/química , Adenoma Pleomórfico/patología , Adulto , Anticuerpos Monoclonales , Femenino , Humanos , Inmunohistoquímica/métodos , Masculino , Persona de Mediana Edad , Mucina 5AC , Mucina 2 , Mucina 4 , Mucina 6 , Mucinas/análisis , Análisis Multivariante , Recurrencia Local de Neoplasia/patología , Factores de Riesgo , Neoplasias de las Glándulas Salivales/patologíaRESUMEN
OBJECTIVE: To examine cyclooxygenase (COX)-2 expression (a key enzyme in the synthesis of prostaglandins, and involved in carcinogenesis of human epithelial tumours) in human transitional cell carcinomas (TCCs) of the renal pelvis and ureter, and to determine whether COX-2 expression correlates with the clinicopathological characteristics of the disease. MATERIALS AND METHODS: Specimens from 144 patients with TCC of the upper urinary tract who had undergone nephroureterectomy were analysed immunohistochemically, and 23 were also analysed by immunoblotting. RESULTS: Immunoblot analysis showed COX-2 immunoreactivity in 17 (74%) of 23 tumours, but not in normal transitional epithelium. COX-2 was localized to the cytoplasm of cancer cells and expressed in 108 (75%) of 144 tumours, as assessed by immunohistochemical analysis. COX-2 expression correlated with tumour grade (P < 0.008), being detected in one of nine grade 1, 77 (79%) of 97 grade 2 and 30 (79%) of 38 grade 3 tumours. Other variables including tumour stage were not associated with COX-2 expression. CONCLUSIONS: We show for the first time that COX-2 is frequently expressed in TCC of the upper urinary tract and is associated with the degree of tumour cell differentiation, indicating that COX-2 may be involved in TCC carcinogenesis at an early and/or late stage, and could be a useful target for chemoprevention of this type of cancer.
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Carcinoma de Células Transicionales/enzimología , Isoenzimas/metabolismo , Neoplasias Renales/enzimología , Proteínas de Neoplasias/metabolismo , Prostaglandina-Endoperóxido Sintasas/metabolismo , Anciano , Ciclooxigenasa 2 , Femenino , Humanos , Inmunohistoquímica/métodos , Pelvis Renal , Masculino , Proteínas de la Membrana , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
An endopeptidase was purified and characterized from green leaves of cucumber (Cucumis sativus L. suyo). The purified enzyme, a basic amino acid-specific endopeptidase with a pI of 5.0, was a monomeric protein of 80 kDa whose pH optimum was 9.5. Inhibitor analysis suggested that it was a serine endopeptidase and contained sulfhydryl groups essential for catalytic activity. Analysis of internal amino acid sequences of the endopeptidase showed no significant similarity to other proteins. Its activity was inhibited by L-Arg and guanidino compounds having high hydrophobicity, as well as divalent cations such as Mg2+ and Ca2+. The K(i) values of L-Arg and Mg2+, which are also likely in vivo inhibitors, were 3.5 and 10 mM, respectively. Inhibition by L-Arg and Mg2+ was additive, and more than 70% of the activity was reversibly inhibited under their physiologically significant concentrations. These results suggest that the enzyme is possibly regulated by L-Arg and/or guanidino compounds, and by divalent cations in vivo.
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Arginina/farmacología , Cucumis sativus/enzimología , Endopeptidasas/metabolismo , Inhibidores Enzimáticos/farmacología , Glicina/análogos & derivados , Glicina/farmacología , Serina Endopeptidasas , Agmatina/farmacología , Arginina/análogos & derivados , Calcio/farmacología , Endopeptidasas/aislamiento & purificación , Etilmaleimida/farmacología , Magnesio/farmacología , Hojas de la Planta/enzimologíaRESUMEN
In this study we investigated whether Tc-99m hexakis 2-methoxy isobutyl isonitnile (Tc-99m MIBI) single-photon emission computed tomography (SPECT) has a correlation with the multidrug resistance (MDRI) and multidrug resistance-associated protein (MRP1) gene expression levels in non-small cell lung cancer (NSCLC). Fifteen patients with NSCLC were studied. SPECT images were obtained 15 (early) and 120 (delayed) min after injection of Tc-99m MIBI. We chose only one transverse section and set the region of interest over the tumor and out of the body. The mean counts in the tumor on early and delayed images were corrected by using those in the background and represented as Te and Td, respectively. Resected tumor specimens were frozen with liquid nitrogen and each positive control cell line was cultured. After the total ribonucleic acid (RNA) was extracted from specimens and cell lines, the complimentary deoxyribonucleic acid (cDNA) was amplified by the reverse transcription-polymerase chain reaction (RT-PCR) method. Each product was electrophoresed and fluorointensity was measured. The gene expression level was represented as the ratio of that of the positive control cell line. Te and Td indicated a significant correlation with the MDR1 gene expression level (p = 0.015 and p = 0.022), but not the gene of MRP1 (p = 0.100 and p = 0.145). In conclusion, Te and Td are useful parameters in predicting the MDRI gene expression level, but not MRPI in NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/genética , Genes MDR , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Radiofármacos , Tecnecio Tc 99m Sestamibi , Anciano , Resistencia a Múltiples Medicamentos/genética , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
We purified a glutamyl endopeptidase that is a major foliar endopeptidase in cucumber. The endopeptidase had a molecular mass of 400 kDa, consisted of four subunits of 97 kDa, and was inactivated by SH-modifying reagents. Its optimum pH and optimum temperature were 8.0 and 30-37 degrees C, respectively. An internal amino acid sequence of the endopeptidase was highly homologous to a partial sequence of unidentified proteins deduced from genetic information for Arabidopsis thaliana, soybean and rice, but not to the sequences of bacterial glutamyl endopeptidases or animal proteases. Therefore, the unidentified proteins might be glutamyl endopeptidases and be widely distributed only among plant species. The activity of the cucumber glutamyl endopeptidase was inhibited by at least three inhibitors existing in cucumber leaves. One of the inhibitors was a competitive inhibitor of 25 kDa, which did not significantly inhibit commercial endopeptidases derived from animals and microorganisms. This suggests that the cucumber glutamyl endopeptidase might be controlled by endogenous inhibitors in vivo.
Asunto(s)
Cucumis sativus/química , Hojas de la Planta/química , Serina Endopeptidasas/química , Serina Endopeptidasas/aislamiento & purificación , Secuencia de Aminoácidos , Cucumis sativus/enzimología , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Peso Molecular , Hojas de la Planta/enzimología , Inhibidores de Proteasas/aislamiento & purificación , Inhibidores de Proteasas/metabolismo , Alineación de Secuencia , Serina Endopeptidasas/metabolismo , TemperaturaRESUMEN
Non-nodulated soybean (Glycine max (L.) Merr.) plants were cultivated hydroponically under N-sufficient (5 mM NaNO(3)) or N-deficient (0.5 mM NaNO(3)) conditions. (13)N- or (15)N- labelled nitrate was fed to the cut end of the stems, and the accumulation of nitrate-derived N in the pods, nodes and stems was compared. Real-time images of (13)N distribution in stems, petioles and pods were obtained using a Positron Emitting Tracer Imaging System for a period of 40 min. The results indicated that the radioactivity in the pods of N-deficient plants was about 10 times higher than that of N-sufficient plants, although radioactivity in the stems and nodes of N-deficient versus N-sufficient plants was not different. A similar result was obtained by supplying (15)NO(3) to cut soybean shoots for 1 h. The fact that the N translocation into the pods from NO(3) fed to the stem base was much faster in N-deficient plants may be due to the strong sink activity of the pods in N-deficient plants. Alternatively, the redistribution of N from the leaves to the pods via the phloem may be accelerated in N-deficient plants. The temporal accumulation of (13)NO(3) in nodes was suggested in both N-sufficient and N-deficient plants. In one (13)NO(3) pulse-chase experiment, radioactivity in the stem declined rapidly after transferring the shoot from the (13)NO(3) solution to non-labelled NO(3); in contrast, the radioactivity in the node declined minimally during the same time period.
Asunto(s)
Glycine max/metabolismo , Nitrógeno/farmacocinética , Semillas/metabolismo , Aminoácidos/análisis , Frutas/metabolismo , Hidroponía , Marcaje Isotópico , Nitratos/análisis , Nitrógeno/administración & dosificación , Nitrógeno/deficiencia , Radioisótopos de Nitrógeno/farmacocinética , Brotes de la Planta/química , Brotes de la Planta/metabolismo , Semillas/química , Glycine max/química , Tomografía Computarizada de EmisiónRESUMEN
Three-dimensional CT angiography was reconstructed from the hepatic artery using multislice CT, and the effect of pitch during scanning on the quality of obtained images was examined. We randomly divided patients into two groups, with images of one group scanned at helical pitch 3 and images of the other at helical pitch 5.5. CT angiography was reconstructed by a volume-rendering technique. Evaluation was done visually, taking the sharpness of images of branches of the hepatic artery as a measure. Three-dimensional imaging scanned at pitch 3 tended to be better than that scanned at pitch 5.5.
Asunto(s)
Angiografía/métodos , Arteria Hepática/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Recent advances in the treatment of hepatocellular carcinoma (HCC) have prolonged patient survival. However, the number of patients with bone metastases identified during follow-up examinations has increased. Tc-99m Sn-N-pyridoxy-5-methyltryptophan (Tc-99m PMT) has been reported to accumulate at a high rate in HCC lesions and bone metastases. In the patient described here, whole-body scintigraphy showed accumulation of DTPA galactosyl human serum albumin (Tc-99m GSA) and Tc-99m PMT in bone metastases from HCC. The authors suggest that asialoglycoprotein receptors may be present in bone metastases from well-differentiated HCC. Tc-99m GSA whole-body imaging can be used to detect bone metastases from HCC and to evaluate hepatic reserve.
Asunto(s)
Albúminas , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/secundario , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/secundario , Neoplasias Hepáticas/patología , Compuestos de Organotecnecio , Radiofármacos , Medronato de Tecnecio Tc 99m/análogos & derivados , Triptófano/análogos & derivados , Humanos , Masculino , Persona de Mediana Edad , CintigrafíaRESUMEN
Detection of metastatic lesions by bone scintigraphy is highly sensitive but has a low rate of specificity. Often bone metastases from hepatocellular carcinoma are not detected by bone scintigraphy because of low uptake or a photopenic area in the tumor. In contrast, Tc-99m Sn-N-pyridoxy-5-methyltryptophan (Tc-99m PMT) whole-body scintigraphy reflects tumor viability, and the specificity of detection is so high that tumor structure can be shown well. Tc-99m PMT whole-body scintigraphy was helpful for evaluating the response to therapy and monitoring the course of the patient described here with bone metastasis from hepatocellular carcinoma.
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Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/secundario , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/secundario , Neoplasias Hepáticas/patología , Compuestos de Organotecnecio , Radiofármacos , Triptófano/análogos & derivados , Huesos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Cintigrafía , Sensibilidad y EspecificidadRESUMEN
Serial changes in N-isopropyl-p[125I]-iodoamphetamine (125I-IMP) in mouse lungs were observed with a confocal laser scanning microscope. Male mice were intravenously injected with 125I-IMP and subjected to autoradiographic procedures 20 minutes, and 3 and 24 hours after injection. Differential interference contrast (DIC) images and confocal images were obtained with a confocal laser scanning microscope, and superimposed images were evaluated. Large numbers of silver grains were observed in the interstitium, bronchioles, and alveolar sacs 20 minutes after the injection, and lamellar distribution of the grains was observed on the ciliary surface. The numbers of silver grains in the interstitium and bronchioles had decreased 3 hours after the injection of 125I-IMP, but the numbers of silver grains in the alveolar spaces had not. Although small numbers of silver grains remained in both the bronchioles and alveolar sacs 24 hours after the injection, most of them had washed out. Confocal laser scanning microscopy is considered to be a useful procedure for studying the distribution of radioisotopes by microautoradiography, because it allows clear autoradiographs to be obtained in which tissues and silver grains are perfectly matched and all silver grains are in focus.
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Yofetamina/farmacocinética , Pulmón/metabolismo , Animales , Autorradiografía , Cinética , Pulmón/citología , Masculino , Ratones , Ratones Endogámicos ICR , Microscopía Confocal , Radiofármacos/farmacocinética , Factores de Tiempo , Distribución TisularRESUMEN
We sought to examine whether the antiarrhythmic effect of E4031 (E), or I(Kr) channel blocker, is affected by beta-adrenergic stimulation using isoproterenol (Iso) or by beta-adrenergic blockade (betaB) using, ONO1101, in a canine myocardial infarction model. Electrophysiologic studies were performed in 10 dogs with 7-day-old myocardial infarctions. Local QT intervals were measured at 47 sites on the infarcted myocardium using a mapping electrode. QT dispersion (QTd), as defined by the coefficient of variation of QT intervals, was obtained. Inducibility of ventricular arrhythmias was examined by programmed stimulation. These procedures were repeated during administration of E, E + Iso, and E + betaB. The effect of prolonging local QT intervals by E was counteracted by Iso, and was accentuated by betaB. The amount of prolongation was dependent on the baseline QT intervals, and QTd showed a tendency to decrease with E, to increase with E + Iso, and significantly decreased with E + betaB. Ventricular tachyarrhythmias were induced in a half of dogs with E + Iso, but were not induced with E + betaB. In the presence of adrenergic activation, I(Kr) blockers may exhibit a decreased antiarrhythmic effect. Beneficial synergism can be expected when an I(Kr) blocker is combined with a beta-blocker in the subacute phase of myocardial infarction.
Asunto(s)
Antagonistas Adrenérgicos beta/farmacología , Antiarrítmicos/farmacología , Infarto del Miocardio/tratamiento farmacológico , Bloqueadores de los Canales de Potasio , Animales , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/prevención & control , Modelos Animales de Enfermedad , Perros , Quimioterapia Combinada , Electrocardiografía , Femenino , Corazón/efectos de los fármacos , Corazón/fisiopatología , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/fisiopatología , Masculino , Morfolinas/farmacología , Infarto del Miocardio/fisiopatología , Piperidinas/farmacología , Piridinas/farmacología , Urea/análogos & derivados , Urea/farmacologíaRESUMEN
Galectin-3 is a member of the beta-galactoside-binding protein family that plays an important role in cell-cell adhesion and in cell-matrix interaction. We have examined the expression of galectin-3 in normal, adenomatous, and malignant thyroid tissues and also in metastatic lesions. Galectin-3 was rarely expressed in normal thyroid tissue but was abundant in the cytoplasm of the neoplastic lesions. Among neoplastic lesions, galectin-3 was expressed to a greater extent in follicular carcinomas than in follicular adenomas and was present in greater amounts in papillary carcinomas than in follicular adenomas or carcinomas. Primary lesions of papillary carcinoma with metastasis contained significantly higher concentrations of galectin-3 than tumors of this type without metastases. However, the expression of galectin-3 was significantly decreased in metastatic lesions in the lymph nodes compared with their primary lesions. From these results, we assumed that galectin-3 works in different ways at different stages of thyroid neoplasm proliferation. Among primary tumors, galectin-3 expression is significantly different in 3 histological types. However, the continuity of progression among these tumors is not yet proven. In later stages, decreased expression of galectin-3 may aid the release of cancer cells from the primary lesions for invasion and metastasis.
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Adenocarcinoma Folicular/metabolismo , Adenoma/metabolismo , Antígenos de Diferenciación/metabolismo , Carcinoma Papilar/metabolismo , Lectinas/metabolismo , Ganglios Linfáticos/patología , Neoplasias de la Tiroides/metabolismo , Adenocarcinoma Folicular/secundario , Adenoma/patología , Antígenos de Diferenciación/análisis , Carcinoma Papilar/secundario , Electroforesis en Gel de Poliacrilamida , Galectina 3 , Humanos , Técnicas para Inmunoenzimas , Metástasis Linfática/patología , Neoplasias de la Tiroides/patologíaRESUMEN
It has been reported that 10% of patients with pheochromocytoma experience recurrence despite surgery. The authors administered I-123 MIBG to patients with recurrent pheochromocytoma and found that early images are more useful than delayed images to detect recurrence. Early imaging with I-123 MIBG is useful for postoperative follow-up studies in patients with pheochromocytoma and those with possible tumor recurrence.
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3-Yodobencilguanidina , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Feocromocitoma/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Humanos , Procesamiento de Imagen Asistido por Computador , Radioisótopos de Yodo , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Radiofármacos , Factores de Tiempo , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
PURPOSE: We performed technetium-99m hexakis-2-methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) in 23 patients with primary lung cancer between July 1993 and March 1996. We evaluated the relationships among the uptake ratio, retention index and the prognosis after radiation therapy and/or chemotherapy. MATERIALS AND METHODS: Tc-99m MIBI SPECT was performed at 30 minutes and at 3 hours after intravenous injection of 600 MBq of Tc-99m MIBI with three gamma camera detectors (GCA-9300A/HG) on transverse SPECT images. Regions of interest were set in the area of abnormal uptake of Tc-99m MIBI and in the contralateral normal lung. The ratio of uptake in the lesion to that in the contralateral normal lung was obtained on early images (early ratio; ER) as well as delayed images (delayed ratio: DR). The retention index (RI) was calculated as follows: RI = (DR - ER)/ER x 100. The ratio was compared with survival time and prognostic factors. RESULTS: There was no correlation between ER and DR. The patients with high RI survived longer than those with low RI (median survival, 19.4 months vs. 9.4 months; p = 0.0104 by the Mantel-Cox test). CONCLUSION: These results suggest that RI is the most useful among Tc-99m MIBI indices of primary lung cancer in predicting prognosis.
Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Tecnecio Tc 99m Sestamibi , Adulto , Anciano , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Carcinoma de Células Pequeñas/diagnóstico por imagen , Carcinoma de Células Pequeñas/mortalidad , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Pequeñas/terapia , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Masculino , Persona de Mediana Edad , Pronóstico , Radiofármacos/farmacocinética , Tasa de Supervivencia , Tecnecio Tc 99m Sestamibi/farmacocinética , Factores de Tiempo , Distribución Tisular , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
PURPOSE: The purpose of this work was to assess the scan delay and the effect of flow rates on arterial phase scanning of hepatic CT. METHOD: One hundred twenty patients suspected of having hepatocellular carcinoma were examined by three-phase helical CT using computer-assisted bolus-tracking technology. We set the region of interest (ROI) in the abdominal aorta at the level of the celiac artery as a baseline. The triggering threshold was set at 100 HU. A volume of 100 ml of iomeprol (350 mg of I/ml) was administered at 2, 2.5, or 3 ml/s i.v. RESULTS: In all cases, helical CT scanning began after reaching the ROI threshold. Then, portal venous phase scanning was initiated 50 s after arterial phase initiation. The mean delay time from the initiation of contrast agent administration to the beginning of arterial phase scanning was 29.2 +/- 3.8 s (mean +/- SD, range 22-39 s). A faster injection rate significantly shortened the scan delay (p < 0.01). In portal venous phase scanning, calculated areas under the hepatic enhancement curves were almost equal among different injection rates. CONCLUSION: The computer-assisted bolus-tracking technology is a useful method for determining an individual scan delay of arterial phase CT.
Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Hígado/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Tomografía Computarizada por Rayos X/métodos , Anciano , Aorta Abdominal/diagnóstico por imagen , Área Bajo la Curva , Carcinoma Hepatocelular/diagnóstico , Medios de Contraste/administración & dosificación , Medios de Contraste/farmacocinética , Estudios de Evaluación como Asunto , Femenino , Humanos , Inyecciones Intravenosas , Yopamidol/administración & dosificación , Yopamidol/análogos & derivados , Yopamidol/farmacocinética , Hígado/metabolismo , Neoplasias Hepáticas/diagnóstico , Masculino , Persona de Mediana Edad , Sensibilidad y EspecificidadRESUMEN
The purpose of this study was to demonstrate the utility of helical CT in assessing the therapeutic effects of endoscopic variceal ligation (EVL). Twenty-four patients with esophageal varices were examined. Helical scanning was initiated 60 s after intravenous injection (Iopamidol 300 mgI/ml, total 120 ml, 3 ml/s) was started. Esophageal varices were clearly depicted as high-density areas. Multiplanar reformation and 3D images demonstrated collateral circulation three-dimensionally. After EVL, mucosal high-density areas had diminished markedly, but collateral veins around the esophagus, and gastro- and/or spleno-renal shunts, were unchanged in all patients. Of 21 patients with collateral circulation, esophageal varices recurred endoscopically in 6 patients within 12 months. In 3 patients without collateral circulation, esophageal varices did not recur within 12 months. From these findings, we conclude that helical CT is a useful method for assessing the therapeutic effects of EVL.
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Várices Esofágicas y Gástricas/diagnóstico por imagen , Várices Esofágicas y Gástricas/terapia , Hemostasis Endoscópica , Tomografía Computarizada por Rayos X/métodos , Circulación Colateral , Femenino , Hemorragia Gastrointestinal/diagnóstico por imagen , Hemorragia Gastrointestinal/terapia , Humanos , Procesamiento de Imagen Asistido por Computador , Ligadura , Masculino , Persona de Mediana Edad , Recurrencia , Tomografía Computarizada por Rayos X/estadística & datos numéricosRESUMEN
OBJECTIVE: To assess the image quality of multiple threshold display (MTD) as a new technique for generating three-dimensional (3D) pulmonary computed tomographic (CT) angiographic images. METHODS: We used MTD, a type of shaded surface display (SSD) offering the selection of multiple thresholds and transparencies, to reconstruct 3D-CT angiograms from enhanced helical CT data sets in 33 patients with lung disease. In MTD, eight thresholds of CT values are selected, and transparency is assigned to each. The selected voxels, ranging from -600 to 1,000 Hounsfield Units, were divided into eight classes, and transparency ranging from 0 to 100% was assigned to each. The CT scanner employed was a Toshiba Xvigor. MTD and SSD images were generated by using an Xtension with a Sun SPARC station 20, and they were compared by two radiologists. RESULTS: The image quality of MTD images was superior to that of SSD images (p < 0.01), because the MTD images demonstrated clearly both the major and small vessels. CONCLUSION: MTD is a useful technique for 3D pulmonary CT angiography.
Asunto(s)
Enfermedades Pulmonares/diagnóstico por imagen , Arteria Pulmonar/diagnóstico por imagen , Venas Pulmonares/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Arteria Pulmonar/patología , Venas Pulmonares/patología , Tomógrafos Computarizados por Rayos XRESUMEN
To optimize scan delay of arterial phase scanning of hepatic CT, 30 patients suspected of having HCC were examined using real-time image reconstruction technology (SureStart). In all cases, SureStart was successful. Despite the low dose, these images allowed adequate visualization of the abdominal aorta. The mean delay from the initiation of contrast administration to the beginning of arterial phase scanning was 29.6 +/- 5.2 sec (mean +/- SD; range, 22-51 sec).