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1.
Aliment Pharmacol Ther ; 48(1): 44-54, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29797518

RESUMEN

BACKGROUND: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. It remains incompletely understood in the real world how anti-viral therapy affects survival after HCC diagnosis. METHODS: This was an international multicentre cohort study of 2518 HBV-related HCC cases diagnosed between 2000 and 2015. Cox proportional hazards models were utilised to estimate hazard ratios (HR) with 95% (CI) for anti-viral therapy and cirrhosis on patients' risk of death. RESULTS: Approximately, 48% of patients received anti-viral therapy at any time, but only 17% were on therapy at HCC diagnosis (38% at US centres, 11% at Asian centres). Anti-viral therapy would have been indicated for >60% of the patients not on anti-viral therapy based on American criteria. Patients with cirrhosis had lower 5-year survival (34% vs 46%; P < 0.001) while patients receiving anti-viral therapy had increased 5-year survival compared to untreated patients (42% vs 25% with cirrhosis and 58% vs 36% without cirrhosis; P < 0.001 for both). Similar findings were seen for other patient subgroups by cancer stages and cancer treatment types. Anti-viral therapy was associated with a decrease in risk of death, whether started before or after HCC diagnosis (adjusted HR 0.62 and 0.79, respectively; P < 0.001). CONCLUSIONS: Anti-viral therapy improved overall survival in patients with HBV-related HCC across cancer stages and treatment types but was underutilised at both US and Asia centres. Expanded use of anti-viral therapy in HBV-related HCC and better linkage-to-care for HBV patients are needed.


Asunto(s)
Antivirales/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/mortalidad , Hepatitis B/tratamiento farmacológico , Hepatitis B/mortalidad , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/mortalidad , Pautas de la Práctica en Medicina/estadística & datos numéricos , Anciano , Asia/epidemiología , Carcinoma Hepatocelular/virología , Estudios de Cohortes , Abuso de Medicamentos/estadística & datos numéricos , Femenino , Mal Uso de los Servicios de Salud/estadística & datos numéricos , Hepatitis B/complicaciones , Virus de la Hepatitis B/fisiología , Humanos , Prescripción Inadecuada/estadística & datos numéricos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/mortalidad , Cirrosis Hepática/virología , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Análisis de Supervivencia , Estados Unidos/epidemiología
2.
Cancer Res ; 61(1): 36-8, 2001 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-11196187

RESUMEN

Microsatellite instability (MSI) and frameshift mutations in genes containing nucleotide repeats have been reported in a subset of colorectal and gastric carcinomas. This study describes the analysis of MSI-positive colorectal (39 cases) and gastric carcinomas (36 cases) for the presence of frameshift mutations of the six genes known to be involved in DNA repair and containing mononucleotide repeats in their coding region. Our mutational study of the 75 MSI-positive tumors revealed frequent mutations in hRAD50 (23 cases, 31%), BLM (16 cases, 21%), and hMSH6 (16 cases, 21%); rare mutations in BRCA1 (1 case, 1%) and ATM (3 cases, 4%); and no mutation in NBS1. In contrast, no frameshift mutation was found in 60 MSI-negative colorectal and gastric carcinomas. The mutation of hRAD50, a gene that is involved in the response to cellular DNA damage and forms a complex with hMRE11 and NBS1, has not been reported previously. Our results suggest that frameshift mutations of hRAD50, BLM, and hMSH6 are selected and play a role in the tumorigenesis of colorectal and gastric carcinomas with MSI. The MSI targeting of the hRAD50 and BLM genes represents an additional link between MSI and DNA repair because alteration of these genes could accelerate defective DNA repair.


Asunto(s)
Adenocarcinoma/genética , Neoplasias Colorrectales/genética , Enzimas Reparadoras del ADN , Proteínas de Unión al ADN/genética , Mutación del Sistema de Lectura , Repeticiones de Microsatélite/genética , Neoplasias Gástricas/genética , Ácido Anhídrido Hidrolasas , Adenosina Trifosfatasas/genética , Proteínas de la Ataxia Telangiectasia Mutada , Proteínas de Ciclo Celular , ADN Helicasas/genética , Análisis Mutacional de ADN , Reparación del ADN/genética , Genes BRCA1/genética , Humanos , Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinasas/genética , RecQ Helicasas , Proteínas Supresoras de Tumor
3.
Oncogene ; 19(39): 4549-52, 2000 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-11002428

RESUMEN

The angiopoietin-Tie2 system in endothelial cells is an important regulator of vasculogenesis and vascular integrity. High levels of angiopoietin-2 (Ang2) mRNA are observed in vascular activation during tumorigenesis. Although Ang2 is known to be a naturally occurring antagonist of angiopoietin-1 (Ang1) in vivo, the exact function of Ang2 itself is not known. Here, we found that a high concentration of Ang2 (800 ng/ml) acts as an apoptosis survival factor for endothelial cells during serum deprivation apoptosis. The survival effect of high concentration Ang2 was blocked by pre-treatment with soluble Tie2 receptor and the PI 3'-kinase-specific inhibitors, wortmannin and LY294002. Accordingly, 800 ng/ml of Ang2 induced phosphorylation of Tie2, the p85 subunit of phosphatidylinositol 3'-kinase (PI 3'-kinase), and serine-threonine kinase Akt at Ser473 in the human umbilical vein endothelial cells; lower concentrations of Ang2 (50 - 400 ng/ml) did not produce notable effects. These findings indicate that at high concentrations, Ang2, like Ang1, can be an apoptosis survival factor for endothelial cells through the activation of the Tie2 receptor, PI 3'-kinase and Akt, and thus may be a positive regulator of tumor angiogenesis. Oncogene (2000) 19, 4549 - 4552.


Asunto(s)
Endotelio Vascular/citología , Endotelio Vascular/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas/farmacología , Proteínas Proto-Oncogénicas/metabolismo , Androstadienos/farmacología , Angiopoyetina 2 , Apoptosis/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cromonas/farmacología , Medio de Cultivo Libre de Suero/farmacología , Relación Dosis-Respuesta a Droga , Endotelio Vascular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Humanos , Morfolinas/farmacología , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/farmacología , Fosfatidilinositol 3-Quinasas/efectos de los fármacos , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación , Proteínas Proto-Oncogénicas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt , Receptor TIE-2 , Transducción de Señal , Venas Umbilicales/citología , Wortmanina
5.
Cancer Lett ; 138(1-2): 227-32, 1999 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-10378798

RESUMEN

To define the commonly deleted region on chromosome 8p for further positional cloning of the putative tumor suppressor gene, we carried out allelic imbalance (AI) studies in 41 HCCs using a panel of 37 microsatellite markers. The overall AI on 8p was 87.8% (36 of 41). Among the 36 cases with AI, 13 cases showed AI in all of the loci, suggesting entire deletion on the short arm of chromosome 8, while the remaining 23 cases showed partial AI. Detailed deletion mapping identified two independent commonly deleted regions on chromosome 8p. These were as follows: (1) centered by the D8S1819 and D8S1706 loci between the D8S561 and D8S1825 loci, (2) centered by the D8S1733 locus between the D8S298 and D8S1739 loci. These results suggest that the two putative tumor suppressor genes may be present on chromosome 8p.


Asunto(s)
Carcinoma Hepatocelular/genética , Cromosomas Humanos Par 8 , Neoplasias Hepáticas/genética , Pérdida de Heterocigocidad , Carcinoma Hepatocelular/patología , Mapeo Cromosómico , Humanos , Neoplasias Hepáticas/patología
6.
Mol Cells ; 10(3): 281-8, 2000 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-10901166

RESUMEN

Recent advances in the study of globin gene switching in the context of complete gene locus have contributed greatly to our understanding of developmental regulation mechanism of globin gene expression. However, it is not clear yet whether the cluster is sufficient in proper gene switching when the globin genes are replaced with conventional reporter genes. Furthermore, even though erythroid-specific and ubiquitous transcription factors involved in erythroid-specific globin gene expression have been characterized and some plausible globin gene switching models have been suggested, any specific factor directly involved in globin gene switching is not yet identified. In this study, as an effort to further understand globin switching mechanism and to identify globin switching factors, we constructed reporter vectors by juxtaposing several putative regulatory elements in human beta-globin locus to conventional reporter genes and analyzed their stage-specific expression in erythroid cell lines. At the end, we demonstrated that gammabeta-type constructs, in which both gamma-type and beta-type globin reporter genes were linked in cis below beta-globin locus control region (LCR), show proper stage-specific reporter gene expression in erythroid cell lines and also recapitulate globin switching in cell hybrids.


Asunto(s)
Eritrocitos/metabolismo , Regulación del Desarrollo de la Expresión Génica , Genes Reporteros , Globinas/genética , Animales , Fusión Celular , Vectores Genéticos , Humanos , Células K562 , Leucemia Eritroblástica Aguda , Región de Control de Posición , Ratones , Familia de Multigenes/genética , Secuencias Reguladoras de Ácidos Nucleicos , Factores de Tiempo , Transfección , Células Tumorales Cultivadas
7.
J Exp Psychol Hum Percept Perform ; 24(6): 1690-704, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9861717

RESUMEN

Five experiments addressed the perception of curvilinear heading under various conditions of optical flow. Perception of heading was unaffected by optical noise (Experiment 1) and was successful and equally accurate for flows generated by circular and elliptical paths of locomotion (Experiment 2). In Experiment 3, random perturbations of vector magnitudes in general curvilinear fields did not reduce the accuracy of perceived heading. When vector directions were randomly perturbed in Experiments 4 and 5, curvilinear heading perception was impaired. Discussion focuses on the inappropriateness of the vector normal hypothesis to the general curvilinear case, the importance of the pattern of relative vector directions, and the practical and theoretical significance of investigating different forms of noncanonical optical flow.


Asunto(s)
Movimientos Oculares/fisiología , Percepción de Forma/fisiología , Humanos , Ruido
8.
J Exp Psychol Hum Percept Perform ; 19(1): 179-93, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8440984

RESUMEN

The time derivative (tau) of the inverse of the relative rate of optical expansion (tau) may have critical values with potential implications for controlling activity. The present research addresses the particular hypothesis that tau < -0.5 specifies "unsafe" collision courses and tau > or = -0.5 specifies "safe" collision courses. Optical expansion patterns were simulated on a computer with -1.0 < or = tau < 0 and judged as suggesting a "hard" or "soft" collision. tau < -0.5 led to significantly different decisions from tau > or = -0.5, but the critical value of -0.5 was not perceived reliably as soft, a deviation possibly due to discretely approximating continuous functions. Additional experiments evaluated terminal rates of change and display duration and examined the effects of biasing the presented displays toward the soft or the hard end of the tau continuum. The results were consistent with the tau hypothesis.


Asunto(s)
Atención , Percepción de Distancia , Percepción de Movimiento , Orientación , Aceleración , Aprendizaje Discriminativo , Humanos , Psicofísica , Percepción del Tiempo
9.
J Exp Psychol Hum Percept Perform ; 26(1): 31-56, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10696604

RESUMEN

Five experiments examined circular heading perception with optical flows that departed from the canonical form. Noncanonicity was achieved through nonrigidity of the environment (Experiments 1 and 2), oscillations of the point of observation (Experiment 3), and the bending of light (Experiments 4 and 5). In Experiments 1 and 2, perception was impaired more by nonrigidity of the ground plane than by nonrigidity of the medium. In Experiment 3, perception was unimpaired by noncanonical flows induced by the bounce and sway of observer locomotion. In Experiments 4 and 5, perception was not impaired when light paths were distorted by a spherical projection, but perception was impaired when they were distorted by a sine function. Results are discussed in relation to the hypothesis that the information for perceiving heading is the ordinal pattern of optical flow.


Asunto(s)
Conducta de Elección , Reconocimiento Visual de Modelos , Percepción Visual , Adulto , Femenino , Humanos , Luz , Masculino , Modelos Estadísticos , Óptica y Fotónica , Desempeño Psicomotor , Psicofísica
10.
Med Biol Eng Comput ; 40(2): 200-4, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12043801

RESUMEN

Electronic root canal length measurement devices have made it easier and faster to measure the root canal length of a tooth compared with the conventional radiographic method. Of these electronic apex locators, the frequency-dependent type features greater accuracy and convenience in operation. However, its accuracy is still influenced by the presence of blood and/or the various electrolytes used in root canal therapy. This study describes the development of a new frequency-dependent electronic apex locator featuring electrolyte compensation, utilising an impedance ratio and voltage difference technique to minimise the influence of electrolytes on the accuracy of root canal length measurement. The errors for distances from file tips to apical constrictions were determined in vivo with the device operating with electrolyte compensation. The measured lengths were compared with the true lengths of the extracted teeth determined using a microscope. The mean error was +0.14+/-0.27mm, and 95.2% of the measurements were within the clinical tolerance of +/-0.5mm. It was also found that the degree of accuracy was not dependent on the size of the apical foramen (p = 0.74).


Asunto(s)
Cavidad Pulpar/anatomía & histología , Impedancia Eléctrica , Electrólitos , Humanos
11.
Stud Health Technol Inform ; 52 Pt 2: 1255-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-10384661

RESUMEN

This paper proposes a multichannel spike detection in long term EEG monitoring for epilepsy. It is achieved by wavelet transform(WT), artificial neural network(ANN) and the expert system. First, a small set of wavelet coefficients is used to represent the characteristics of a single channel epileptic spikes and normal activities. The purpose of this WT is to reduce the number of inputs to the ANN. Next, three layer feed-forward network employing the error back propagation algorithm is trained and tested using parameters obtained by the WT. Spikes are identified in individual EEG channels by 16 identical neural networks. Finally, 16-channel expert system based on the context information of adjacent channels is introduced to reject artifacts and produce reliable results. In this study, epileptic spikes and normal activities were selected from 32 patient's EEGs (the seizure disorder: 12, normal: 20) in consensus among experts. The result shows that the WT reduced data input size and the preprocessed ANN had 97% sensitivity and 89.5% selectivity, which were more accurate than that of ANN with the same input size of raw data. In clinical result, our expert rule system, which uses neighboring channel informations, was capable of rejecting artifacts commonly found in EEG recordings.


Asunto(s)
Electroencefalografía/métodos , Epilepsia/diagnóstico , Sistemas Especialistas , Redes Neurales de la Computación , Adolescente , Adulto , Algoritmos , Niño , Electroencefalografía/clasificación , Epilepsia/fisiopatología , Femenino , Humanos , Masculino , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador
12.
No Shinkei Geka ; 16(8): 959-64, 1988 Jul.
Artículo en Japonés | MEDLINE | ID: mdl-3173632

RESUMEN

Although internal carotid-posterior communicating artery (ICPC) aneurysms seem to be one of the easiest to be operated on, some are known difficult to handle and could not be successfully clipped even with all sorts of preparations. It is, therefore, essential to analyze ICPC aneurysms with difficulty in clipping. Out of 106 cases with ICPC aneurysms admitted to Kyoto University Hospital since May 1977, 83 cases have been registered in this study to the exclusion of either non-operated cases or giant aneurysm cases. Cases with difficulty in clipping procedure are selected and classified depending on its causes, which were judged from operation records as well as operative photographs. Angiograms have been checked to discuss whether possible causes of difficulty in clipping could have been suspected preoperatively. Radiometry were also performed in the following items; distance between the anterior clinoid process (ACP) and proximal side of the aneurysmal neck (W) in AP view, distance of proximal side of the neck from ACP (D) and its height (H) from the baseline between the ACP and posterior clinoid process in lateral view. Causes of difficulty in clipping procedure can be grouped as follows: a) ventrally directed dome of the aneurysm (9 cases), b) incision of the plica petroclinoidea anterior (PPA) or removal of the anterior clinoid process (ACP) to identify proximal side of the neck (7 cases: b group), c) saucer-shaped dome with no apparent neck, d) branches of the internal carotid artery from dome.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Enfermedades de las Arterias Carótidas/cirugía , Microcirugia/métodos , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/patología , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/patología , Humanos , Radiografía , Radiometría
13.
J Environ Biol ; 25(4): 431-6, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15907072

RESUMEN

A highly sensitive sodium (Na+) transfer tissue biosensor (STTB) was designed using a frog bladder membrane to measure paralytic shellfish poisons (PSP). The STTB consists, of a Na+ electrode covered by the membrane, which was then integrated into a flow-through system for continuous measurements. In the absence of Na+ channel blocker, active transfer of Na+ occurred from inside to outside across the frog membrane. When the STTB was used to measure the Na+ -dependent dissociation of PSP, it was able to detect PSB at a level contained in a single cell. However, 5 fg or higher (100 cells or more) is needed for accurate and reproducible measurements. The toxicity obtained by the STTB was significantly correlated (r = 0.9449) to that determined by the HPLC. Therefore, the simple method of the STTB can be used not only to detect a low level PSP in toxic plankton populations, but also to monitor poisons in shellfish.


Asunto(s)
Técnicas Biosensibles , Dinoflagelados/química , Monitoreo del Ambiente/métodos , Toxinas Marinas/análisis , Saxitoxina/análogos & derivados , Saxitoxina/análisis , Tetrodotoxina/análisis , Animales , Anuros , Transporte Biológico Activo/fisiología , Cromatografía Líquida de Alta Presión , Membranas/metabolismo , Sodio/metabolismo , Vejiga Urinaria/metabolismo
15.
Ergonomics ; 40(1): 1-27, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8995046

RESUMEN

A haemodynamic monitoring and control task was used to evaluate the ecological approach to interface design for complex high-technology environments. Guidelines proposed by Bennett and Flach (1992) were used to design multilevel displays that made visible (a) anatomical constraints, and (b) causal constraints on haemodynamic systems. These displays were compared with a traditional display that showed pressure and flow values in five separate graphs. Simulations of clinical problems were generated by a computer model and presented in an interactive computer environment. Critical care nurses and nursing students observed changes in pressures and flow corresponding to certain disease states and corrected those states using simulated drugs. For both groups, speed and accuracy were progressively improved by the enhanced, multilevel displays.


Asunto(s)
Presentación de Datos , Unidades de Cuidados Intensivos , Monitoreo Fisiológico , Interfaz Usuario-Computador , Simulación por Computador , Hemodinámica
16.
Percept Psychophys ; 63(7): 1153-70, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11766941

RESUMEN

Current theories of arrival time have difficulty explaining performance in the common but neglected case of nonlinear approach. Global tau, a variable supposed to guide time-to-passage (TTP) judgments of objects approaching on linear trajectories, does not apply to circular movement. However, TTP judgments are surprisingly accurate in such cases. We simulated movement through a three-dimensional cloud of point-lights on various circular trajectories. Arrival-time judgments were found to be above chance when observers had to determine which of two expansionless targets would pass them first. Similar to the inside bias observed in heading studies on circular trajectories, observers showed a strong bias to select the target on the inside of their own curved motion path as passing by first. Analysis of the projected target motion revealed that targets on the inside had lower optical velocities and relatively high optical acceleration rates. Empirical TTP judgments agreed best with a strategy based on relative optical velocity changes.


Asunto(s)
Juicio , Percepción de Movimiento , Percepción del Tiempo , Adulto , Simulación por Computador , Percepción de Distancia , Femenino , Humanos , Masculino , Psicofísica , Detección de Señal Psicológica
17.
IEEE Trans Rehabil Eng ; 7(4): 482-5, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10609636

RESUMEN

A new rehabilitation training system, designated as a virtual cycling system, was developed to improve postural balance control by combining virtual reality (VR) technology with a bicycle. Several parameters including path deviation, path deviation velocity, cycling time, and head movement were extracted and evaluated to quantify the extent of control. The system was effective as a training device and, in addition, the technology might have a wider applicability to the rehabilitation field.


Asunto(s)
Ciclismo , Terapia por Ejercicio/métodos , Equilibrio Postural , Postura , Trastornos de la Sensación/rehabilitación , Procesamiento de Señales Asistido por Computador , Terapia Asistida por Computador/métodos , Interfaz Usuario-Computador , Adulto , Diseño de Equipo , Terapia por Ejercicio/instrumentación , Femenino , Movimientos de la Cabeza , Humanos , Masculino , Trastornos de la Sensación/fisiopatología , Procesamiento de Señales Asistido por Computador/instrumentación , Terapia Asistida por Computador/instrumentación
18.
Artículo en Inglés | MEDLINE | ID: mdl-7950064

RESUMEN

A hemodynamic monitoring and control task was used to explore the utility of perceptually based displays to teach basic hemodynamic principles. The baseline display showed discrete values of key hemodynamic data elements. Alternative displays showed (a) anatomical relationships between those elements, and (b) causal constraints. Critical care nurses and student nurses used simulated "drugs" to correct simple hemodynamic disturbances using the three displays. Showing the anatomic constraints on pressure and flow improved treatment coordination by novices. Showing how etiological factors related to symptoms shortened the time required to reach a criterion level of performance and improved treatment coordination for both novices and experts.


Asunto(s)
Instrucción por Computador , Presentación de Datos , Educación en Enfermería , Hemodinámica , Enseñanza , Gráficos por Computador , Cuidados Críticos , Humanos , Métodos , Monitoreo Fisiológico
19.
Am J Pathol ; 158(2): 655-62, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11159202

RESUMEN

Gastric adenoma is a precancerous lesion of the stomach and its malignant transformation is thought to result from accumulative series of gene alterations. The aim of this study was to determine the pattern of chromosomal changes during gastric carcinogenesis. Pairs of adenoma and carcinoma tissues from 15 gastrectomy cases containing both adenomas and carcinomas in the same (adjacent pairs, 6 cases) and different (non-adjacent pairs, 9 cases) lesions, were analyzed for chromosomal alterations of 39 non-acrocentric chromosomal arms by comparative genomic hybridization (CGH). CGH analysis identified frequent chromosomal alterations in most of the gastric adenomas (14/15, 93%) and all of the carcinomas. The mean number of chromosomal alterations was higher in carcinoma (5.5 for adenoma and 11.7 for carcinoma; P = 0.006, by nonparametric Wilcoxon's test). Losses on the short arm of chromosome 17 were most common in both adenomas (43%) and carcinomas (67%). The pattern of chromosomal alterations in paired gastric adenomas and carcinomas showed greater similarity compared to the non-case pairs and this similarity was increased in the adjacent pairs. Deletion mapping analysis on chromosome 17p also demonstrated that the conserved deletion area was more frequent in the adjacent pairs. Among these 6 adjacent pairs, all had common deletion areas. In contrast, among the 9 non-adjacent pairs, 2 (22%) had common area of deletion, 5 (56%) showed deletion only in the carcinoma, and the remaining 2 (22%) had no deletion on 17p, suggesting diverse genetic changes might be involved in the multiple tumor formation. Our results that common clonal genetic changes between adjacent pairs of gastric adenomas and carcinomas and accumulated genetic changes in the carcinomas provide evidences for the stepwise mode of gastric carcinogenesis through the accumulation of a series of genetic alterations.


Asunto(s)
Adenoma/genética , Carcinoma/genética , Aberraciones Cromosómicas , Neoplasias Gástricas/genética , Adenoma/patología , Anciano , Anciano de 80 o más Años , Carcinoma/patología , Deleción Cromosómica , Mapeo Cromosómico , Cromosomas Humanos Par 17/genética , ADN de Neoplasias/genética , Femenino , Humanos , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Hibridación de Ácido Nucleico/métodos , Neoplasias Gástricas/patología
20.
Br J Cancer ; 81(7): 1116-21, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10584870

RESUMEN

Hyper-activation of mitogen-activated protein kinase (MAPK) has recently been reported in several human cancers and activation of MAPK in those cancers may be associated with carcinogenesis through aberrant cell proliferation. To understand the roles of the MAPK pathway in colorectal tumorigenesis, we examined the status of extracellular signal-regulated protein kinases (ERK1/2) in 21 colorectal tumour specimens and compared it with that of paired normals. The specific MAPK activities were two- to tenfold lower in 71% (15 out of 21 cases) of colorectal tumours compared to those in paired normals. The individual MAPK kinase (MEK) correlated with MAPK activities (P = 0.006). Reduction of the MAPK and MEK activities in colorectal tumours was also observed in adenomas. These results suggested that down-regulation of the MAPK cascade may be caused by early genetic event(s) and that it may be related to the loss of normal growth control. Although MAPK activities were down-regulated both in adenomas and carcinomas, activities of the MAPKs in carcinomas were higher than those of paired adenomas. These results suggested that MAPK activities may be increased in the adenoma-to-carcinoma sequence and that it may play a role in the tumour progression. Observation of the differential regulation of MAPK activities in colorectal tumorigeneis suggested roles for the MAPK pathway in both positive and negative controls of cell growth.


Asunto(s)
Adenoma/enzimología , Carcinoma/enzimología , Neoplasias Colorrectales/enzimología , Sistema de Señalización de MAP Quinasas/fisiología , Secuencia de Aminoácidos , Activación Enzimática , Humanos , Proteínas Quinasas Activadas por Mitógenos , Datos de Secuencia Molecular
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