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In recent years, hypertension has become one of the leading causes of illness and death worldwide. Changes in lifestyle among the population have led to an increasing prevalence of hypertension. This study proposes a non-contact blood pressure estimation method that allows patients to conveniently monitor their blood pressure values. By utilizing a webcam to track facial features and the region of interest (ROI) for obtaining forehead images, independent component analysis (ICA) is employed to eliminate artifact signals. Subsequently, physiological parameters are calculated using the principle of optical wave reflection. The Nelder-Mead (NM) simplex method is combined with the particle swarm optimization (PSO) algorithm to optimize the empirical parameters, thus enhancing computational efficiency and accurately determining the optimal solution for blood pressure estimation. The influences of light intensity and camera distance on the experimental results are also discussed. Furthermore, the measurement time is only 10 s. The superior accuracy and efficiency of the proposed methodology are demonstrated by comparing them with those in other published literature.
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Algoritmos , Determinación de la Presión Sanguínea , Presión Sanguínea , Humanos , Presión Sanguínea/fisiología , Determinación de la Presión Sanguínea/métodos , Hipertensión/fisiopatología , Hipertensión/diagnóstico , Procesamiento de Señales Asistido por ComputadorRESUMEN
Recent developments in nanoscale thermal metrology using electron microscopy have made impressive advancements in measuring either phononic or thermal transport properties of nanoscale samples. However, its potential in material analysis has never been considered. Here we introduce a direct thermal absorbance measurement platform in scanning electron microscope (SEM) and demonstrate that its signal can be utilized for atomic number (Z) analysis at nanoscales. We prove that the measured absorbance of materials is complementary to signals of backscattering electrons but exhibits a much higher collection efficiency and signal-to-noise ratio. Thus, it not only enables successful detections of light elements/compounds under low acceleration voltages of SEM but also allows quantitative Z analyses in agreement with simulations. The direct thermal absorbance measurement platform would become an ideal tool for SEM, especially for thin films, light elements/compounds, or biological samples at nanoscales.
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Electrones , Microscopía Electrónica de RastreoRESUMEN
This study proposed an error-matching measurement and compensation method for curve mating and complex mating. With use of polynomial curve fitting and least squares methods for error analysis, an algorithm for error identification and error compensation were proposed. Furthermore, based on the proposed method, an online error-matching compensation system with an autorevising function module for autogenerating an error-compensated NC program for machining was built. Experimental verification results showed that the proposed method can effectively improve the accuracy of assembly matching. In a curve-type mating experiment, the matching error without compensation was 0.116 mm, and it decreased to 0.048 mm after compensation. The assembly accuracy was improved by 28%. In a complex-type mating experiment, the verification results showed that the error reductions after compensation for three mating shapes (straight line, triangle, and curve shape) were 81%, 87%, and 79%, respectively. It showed that the proposed method can improve the assembly accuracy for complex mating shapes, which would also be improved without losing production efficiency.
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Algoritmos , Análisis de los Mínimos CuadradosRESUMEN
This study investigated the ability of aerosolized bovine lactoferrin (bLF) to protect the lungs from injury induced by chronic hyperoxia. Female CD-1 mice were exposed to hyperoxia (FiO2 = 80 %) for 7 days to induce lung injury and fibrosis. The therapeutic effects of bLF, administered via an aerosol delivery system, on the chronic lung injury induced by this period of hyperoxia were measured by bronchoalveolar lavage, lung histology, cell apoptosis, and inflammatory cytokines in the lung tissues. After exposure to hyperoxia for 7 days, the survival of the mice was significantly decreased to 20 %. The protective effects of bLF against hyperoxia were further confirmed by significant reductions in lung edema, total cell numbers in bronchoalveolar lavage fluid, inflammatory cytokines (IL-1ß and IL-6), pulmonary fibrosis, and apoptotic DNA fragmentation. The aerosolized bLF protected the mice from oxygen toxicity and increased the survival fraction to 66.7 % in the hyperoxic model. The results support the use of an aerosol therapy with bLF in intensive care units to reduce oxidative injury in patients with severe hypoxemic respiratory failure or chronic obstructive pulmonary disease.
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Hiperoxia/tratamiento farmacológico , Lactoferrina/administración & dosificación , Lesión Pulmonar/prevención & control , Administración por Inhalación , Animales , Apoptosis/efectos de los fármacos , Bovinos , Citocinas/biosíntesis , Citocinas/genética , Modelos Animales de Enfermedad , Sistemas de Liberación de Medicamentos , Femenino , Humanos , Hiperoxia/complicaciones , Hiperoxia/patología , Factores Inmunológicos/administración & dosificación , Inflamación/patología , Inflamación/prevención & control , Lesión Pulmonar/etiología , Lesión Pulmonar/patología , Ratones , Ratones Endogámicos ICR , Fibrosis Pulmonar/etiología , Fibrosis Pulmonar/patología , Fibrosis Pulmonar/prevención & controlRESUMEN
Backscattered electron (BSE) imaging based on scanning electron microscopy (SEM) has been widely used in scientific and industrial disciplines. However, achieving consistent standards and precise quantification in BSE images has proven to be a long-standing challenge. Previous methods incorporating dedicated calibration processes and Monte Carlo simulations have still posed practical limitations for widespread adoption. Here we introduce a bolometer platform that directly measures the absorbed thermal energy of the sample and demonstrates that it can help to analyze the atomic number (Z) of the investigated samples. The technique, named Atomic Number Electron Microscopy (ZEM), employs the conservation of energy as the foundation of standardization and can serve as a nearly ideal BSE detector. Our approach combines the strengths of both BSE and ZEM detectors, simplifying quantitative analysis for samples of various shapes and sizes. The complementary relation between the ZEM and BSE signals also makes the detection of light elements or compounds more accessible than existing microanalysis techniques.
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Since the outbreak of COVID-19, as of January 2023, there have been over 670 million cases and more than 6.8 million deaths worldwide. Infections can cause inflammation in the lungs and decrease blood oxygen levels, which can lead to breathing difficulties and endanger life. As the situation continues to escalate, non-contact machines are used to assist patients at home to monitor their blood oxygen levels without encountering others. This paper uses a general network camera to capture the forehead area of a person's face, using the RPPG (remote photoplethysmography) principle. Then, image signal processing of red and blue light waves is carried out. By utilizing the principle of light reflection, the standard deviation and mean are calculated, and the blood oxygen saturation is computed. Finally, the effect of illuminance on the experimental values is discussed. The experimental results of this paper were compared with a blood oxygen meter certified by the Ministry of Health and Welfare in Taiwan, and the experimental results had only a maximum error of 2%, which is better than the 3% to 5% error rates in other studies The measurement time was only 30 s, which is better than the one minute reported using similar equipment in other studies. Therefore, this paper not only saves equipment expenses but also provides convenience and safety for those who need to monitor their blood oxygen levels at home. Future applications can combine the SpO2 detection software with camera-equipped devices such as smartphones and laptops. The public can detect SpO2 on their own mobile devices, providing a convenient and effective tool for personal health management.
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Genetic recombination is a well-known phenomenon for enteroviruses. In this study, we determined the phylogenetic relationships of five distinct regions of the EV71 genome for 73 EV71 isolates from 1986 and from 1998 to 2005 in Taiwan. Phylogenetic analyses showed that the 5'-UTR, VP4-VP2, VP1, and 3D regions of EV71 isolated in 2004 and 2005 were grouped into genotype C. However, the 2B region of these isolates differed in that it grouped with genotype B, indicating recombination within EV71 had occurred. This intratypic recombination was first seen in 2002 and became predominant in 2004 and 2005. The simplot and bootscan analyses identified two recombination points located at the 3'-termini of the 2A and 3C regions. This intratypic recombination was identified among naturally circulating EV71 isolates in Taiwan, therefore, it suggests that nonstructural genes may recombine to produce new EV71 variants.
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Enterovirus Humano A/genética , Infecciones por Enterovirus/virología , Recombinación Genética , Regiones no Traducidas 5'/genética , Análisis por Conglomerados , Enterovirus Humano A/aislamiento & purificación , Evolución Molecular , Genoma Viral , Genotipo , Humanos , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Análisis de Secuencia de ADN , Homología de Secuencia , Taiwán , Proteínas Virales/genéticaRESUMEN
The effect of inorganic nutrients (sulfate, phosphate, and ammonium chloride) on the aerobic biodegradation of benzene, toluene, and xylene (BTX) by Pseudomonas spp. was studied in the laboratory using a glass sand tank. The increase of nutrient levels resulted in enhanced bacterial growth and BTX degradation. Sulfate and phosphate serve as key electron acceptors in the microbiological processes degrading BTX. The observed bacterial morphological changes during BTX degradation reveal that the filamentous bacteria were the dominant species at low temperatures about 20 degrees C. The spherical and rod-shaped cells became dominant at higher temperatures ranging from 25 degrees C to 28 degrees C. When the BTX mixture was allowed to be biodegraded for longer incubation periods of 21-42 h at high phosphate concentrations, large amounts of rod-shaped cells were clustered. The morphological adaptation appears to be controlled by the temperature and nutrient levels in the sandy medium where Pseudomonas spp. thrives.
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Benceno/metabolismo , Alimentos , Modelos Biológicos , Pseudomonas/metabolismo , Dióxido de Silicio/metabolismo , Tolueno/metabolismo , Aerobiosis , Cloruro de Amonio/farmacología , Secuencia de Bases , Biodegradación Ambiental/efectos de los fármacos , ADN Bacteriano/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Concentración de Iones de Hidrógeno , Fosfatos/farmacología , Porosidad , Pseudomonas/clasificación , Pseudomonas/genética , Pseudomonas/crecimiento & desarrollo , Pseudomonas/ultraestructura , Sulfatos/farmacología , Temperatura , Factores de Tiempo , Xilenos/metabolismoRESUMEN
OBJECTIVE: To define a rational guideline for the removal of uterine fibroids after laparoscopic myomectomy (LM) by culdotomy or morcellator in multiparae. STUDY DESIGN: A total of 416 multiparae receiving LM were retrospectively studied between November 1997 and January 2014. Of these, 335 had fibroids removed by culdotomy and 81 by a laparoscopic 15mm electromechanical morcellator. Data on parity, number, size and weight of fibroids, operating time, specimen removal time, blood loss, postoperative stay, hospital charges and complications were recorded. The patients were analyzed in four subgroups stratified by main fibroid size and type of procedure. RESULTS: There was no significant difference in body mass index, number of fibroids removed, blood loss, complications, and hospitalization duration between the groups. For fibroids below 10cm, the morcellator was significantly faster compared to culdotomy (10min versus 12min, p<0.001). For fibroids 10cm and above, there was no significant difference in time by culdotomy compared to morcellator (24min versus 20min, p=0.497). The electromechanical morcellator was significantly more expensive. CONCLUSION: Fibroid size of 10cm may be used as a guide for the route of fibroid removal; below 10cm the morcellator is faster but more expensive, for fibroids 10cm and above, culdotomy can be considered as it has a similar removal time to the morcellator in multiparae.
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Colpotomía , Laparoscopía/métodos , Leiomioma/cirugía , Miomectomía Uterina/métodos , Neoplasias Uterinas/cirugía , Adulto , Femenino , Humanos , Laparoscopía/instrumentación , Modelos Lineales , Persona de Mediana Edad , Paridad , Estudios Retrospectivos , Resultado del Tratamiento , Miomectomía Uterina/instrumentaciónRESUMEN
Various infra-red and planar chiral metamaterials were fabricated using the modified Nanospherical-Lens Lithography. By replacing the light source with a hand-held ultraviolet lamp, its asymmetric light emission pattern produces the elliptical-shaped photoresist holes after passing through the spheres. The long axis of the ellipse is parallel to the lamp direction. The fabricated ellipse arrays exhibit localized surface plasmon resonance in mid-infra-red and are ideal platforms for surface enhanced infra-red absorption (SEIRA). We also demonstrate a way to design and fabricate complicated patterns by tuning parameters in each exposure step. This method is both high-throughput and low-cost, which is a powerful tool for future infra-red metamaterials applications.
RESUMEN
Plasmon hybridization modes are observed in the extinction spectra of a metal-insulator-metal (MIM) nanodisk array fabricated using nanospherical-lens lithography. Two distinct hybridization modes are observed in this vertically aligned configuration. Theoretical simulation indicates that the bonding mode located at a lower energy level exhibits an antiphase charge distribution and corresponds to the dark plasmon mode. This is vastly different compared to antibonding dark plasmon mode observed in the conventional dimer configuration. The observed mode is tunable over a wide spectral range simply by varying the insulator thickness and the diameters of the MIM nanodisks. Absorption is the dominating extinction process for the dark plasmon, while scattering dominates the bright plasmon mode. The ability to experimentally measure and tune dark plasmon modes using a MIM configuration should catalyze more novel studies that take full advantages of the absorption-dominated dark plasmon mode.
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The authors report the influence of CrN nanoisland inserted on growth of baseball-bat InN nanorods by plasma-assisted molecular beam epitaxy under In-rich conditions. By inserting CrN nanoislands between AlN nucleation layer and the Si (111) substrate, it was found that we could reduce strain form Si by inserting CrN nanoisland, FWHM of the x-ray rocking curve measured from InN nanorods from 3,299 reduced to 2,115 arcsec. It is due to the larger strain from lattice miss-match of the film-like InN structure; however, the strain from lattice miss-match was obvious reduced owing to CrN nanoisland inserted. The TEM images confirmed the CrN structures and In droplets dissociation from InN, by these results, we can speculate the growth mechanism of baseball-bat-like InN nanorods.
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PURPOSE: This study was designed to show, in certain patients, that colonic epithelial cells can be present in peripheral blood while absent in portal venous blood. METHODS: The circulating colorectal epithelial cells were detected by a reverse transcriptase-polymerase chain reaction assay, which involved amplifying guanylyl cyclase C transcripts. Portal venous and peripheral blood samples were obtained at intervals from 58 patients undergoing colorectal cancer surgery. RESULTS: Circulating colonic epithelial cells were more frequently detected in portal venous blood than in peripheral blood only before mobilization of the tumor-bearing colon segment in patients with tumors of Stage B. In five other patients, before mobilization of their tumor-bearing colon segments, and in another three patients, during the mobilization, colorectal epithelial cells were detected in peripheral blood but not in portal venous blood. These eight patients had Stage C or D tumors. CONCLUSION: In 8 of 58 patients, colorectal epithelial cells were detected in peripheral but not in portal venous blood. Metastatic deposits in lymphatic vessels or liver might be the source of these cells.
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Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/cirugía , Células Epiteliales/fisiología , Células Neoplásicas Circulantes , Vena Porta/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Colon/irrigación sanguínea , Colon/fisiopatología , Colon/cirugía , Neoplasias Colorrectales/fisiopatología , Femenino , Guanilato Ciclasa/sangre , Humanos , Masculino , Persona de Mediana Edad , Receptores de Enterotoxina , Receptores Acoplados a la Guanilato-Ciclasa , Receptores de Péptidos/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Circulación Esplácnica/fisiología , Factores de TiempoRESUMEN
Laparoscopy-assisted colectomy is technically feasible, but objective evidence of its benefits remains scarce. This study was done to evaluate the outcomes and operative stress of laparoscopy-assisted colectomy versus the traditional open method in the management of sigmoid complex polyps that cannot be safely or adequately removed by colonofibroscopy. Between January 1997 and December 1999, a total of 42 patients were equally randomized to the laparoscopy group and the laparotomy group by the blocked randomization method. Three patients randomized to the laparoscopy group did not complete the trial; therefore 18 patients treated by laparoscopy-assisted sigmoidectomy and the other 21 treated by the open method were prospectively evaluated. These two groups of patients were well matched in age, gender, symptoms, tumor location, localization method, tumor size, morphology, histopathology, and the accuracy of the clinical diagnosis. Two standardized surgical strategies, the lateral-to-medial and medial-to-lateral dissection sequences, were performed in 14 and 4 patients of the laparoscopy group, respectively, according to whether their tumors were located above or below 20 cm above the anal verge. After evaluating the surgical outcomes, we found that the laparoscopy group was significantly better than the laparotomy group in regard to parameters that included severity of postoperative pain, wound size, postoperative complication rate, and the duration of postoperative ileus, hospitalization, and disability. There was no significant difference in the operating times for these two groups. However, the costs of the laparoscopy group were significantly higher. To evaluate the surgical stress, we measured the serum C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), total lymphocyte count, and CD4+/CD8+ ratio 24 hours before and after surgery. We found that the postoperative serum CRP level and the ESR were significantly less elevated and the total lymphocyte counts and CD4+/CD8+ ratio were significantly less depressed in the laparoscopy group than in the laparotomy group. We thus concluded that laparoscopy-assisted sigmoidectomy can be safely performed with shorter convalescence and less operative stress but at a higher cost. We strongly recommended the use of this technique in the management of sigmoid complex polyps if the patient's economic status permits.
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Carcinoma/cirugía , Colectomía , Pólipos del Colon/cirugía , Laparoscopía , Evaluación de Procesos y Resultados en Atención de Salud , Neoplasias del Colon Sigmoide/cirugía , Anciano , Carcinoma/patología , Pólipos del Colon/patología , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Neoplasias del Colon Sigmoide/patologíaRESUMEN
This study aimed to compare medial-to-lateral versus lateral-to-medial laparoscopic dissection sequences for resecting rectosigmoid cancers. We hypothesized that the medial-to-lateral approach was a more efficient procedure and with potentially better oncologic results. Between January 1997 and June 1999, a total of 67 patients of rectosigmoid cancer treated by one surgeon using the laparoscopic approach were recruited for this prospective, randomized, double-blind clinical trial. Using the blocked randomization method, 36 patients were allocated to a medial-to-lateral (M) group and the other 31 to a lateral-to-medial (L) group; the groups were well matched in age, gender, symptoms, body mass index, American Society of Anesthesiology (ASA) class, tumor location, tumor distance above the anal verge, tumor gross morphology, TNM stage of the tumor, and accuracy of preoperative TNM staging (p > 0.05). All patients were followed up until June 2001. We found that the M group had a significantly shorter operating time and lower overall costs than the L group (p < 0.05). There was no significant difference between these two groups in terms of intraoperative complications, conversion rate, postoperative ileus, hospitalization, postoperative pain, postoperative complications, wound length, or disability (p > 0.05). The postoperative proinflammatory response, evaluated by the C-reactive protein level and the erythrocyte sedimentation rate, was significantly lower in the M group (p < 0.05). There was no significant difference between these two groups regarding postoperative immunosuppression, as evaluated by the alterations of total lymphocyte counts and the CD4(+)/CD8(+) ratio (p > 0.05). The extent of dissection of these two dissection approaches was similar, as the harvested lymph nodes were equivalent (p > 0.05). During the whole follow-up period (median 32 months, range 24-54 months), the tumor recurrence rate was similar for these two groups of patients (5.6% in the M group vs. 6.5% in the L group; p > 0.05). These findings indicated that the medial-to-lateral approach was quicker, less expensive and possibly less invasive; moreover, it gave oncologic results similar to those achieved with the traditional lateral-to-medial dissection sequence. We thus concluded that the medial-to-lateral dissection sequence may currently be the most appropriate procedure for laparoscopic resection of rectosigmoid cancers.
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Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Disección/métodos , Laparoscopía , Neoplasias del Recto/cirugía , Neoplasias del Colon Sigmoide/cirugía , Anciano , Sedimentación Sanguínea , Proteína C-Reactiva/análisis , Femenino , Humanos , Complicaciones Intraoperatorias , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Our study aims to further clarify the prognostic significance of p53 overexpression in stage IV colorectal cancer. Between January 1994 and June 1997, we recruited 144 patients with stage IV colorectal cancers for our study, based on appropriate eligibility criteria. The patients were nonrandomly allocated to 2 treatment groups of either with or without high-dose 5-fluorouracil plus leucovorin chemotherapy (HDFL: 5-Fu: 2,600 mg/m(2) leucovorin 300 mg/m maximum 500 mg). Each treatment group was further divided into 2 subgroups according to the status of p53 overexpression. Therefore, 4 subgroups were allocated in our study and were designated as p53 (overexpression) HDFL (+), n = 65; p53 (normal) HDFL (+), n = 37; p53 (overexpression) HDFL (-), n = 27; and p53 (normal) HDFL (-), n = 15, respectively. All patients were prospectively followed until April 2001. There was no significant difference of the background clinicopathologic data of these 4 allocated subgroups of patients (p > 0.05). Multivariate analysis of various clinicopathologic factors of the whole group of patients indicated that age > or = 60 years, poor differentiation, mucin production, CEA > 100 ng/ml, p53 overexpression and without chemotherapy were the significant independent poor prognostic factors (p < 0.05). Survival analyses indicated that the patients of subgroup p53 (normal) HDFL (+) survived significantly longer than those of subgroup p53 (overexpression) HDFL (+), with mean survival time (95% confidence interval [CI]) of 20.24 (16.24-24.25) and 13.29 (10.98-15.60) months, respectively (p = 0.0043, log-rank test). In contrast, in patients without chemotherapy, the prognosis was poor regardless of their p53 status, with mean survival time (95% CI) of 6.85 (5.47-8.23) and 5.87 (4.48-7.26) months in p53 (overexpression) HDFL (-) and p53 (normal) HDFL (-) subgroups of patients, respectively (p = 0.2820, log-rank test). Cancers of normal p53 expression responded significantly better to HDFL (p < 0.05), with mean response rate (95% CI) being 65.57% (52.18-82.96%) in subgroup p53 (normal) HDFL (+) as compared to 35.38% (23.52-47.24%) in subgroup p53 (overexpression) HDFL (+). The toxicity to HDFL was similarly minimal between p53-normal and p53-overexpression patients (p > 0.05). We thus concluded that the poorer prognosis of stage IV colorectal cancers with p53 overexpression was associated with their poorer chemosensitivity rather than the more biologic aggressiveness.
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Adenocarcinoma/tratamiento farmacológico , Antimetabolitos Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Fluorouracilo/uso terapéutico , Proteínas de Neoplasias/biosíntesis , Proteína p53 Supresora de Tumor/biosíntesis , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Antimetabolitos Antineoplásicos/efectos adversos , Biomarcadores de Tumor/análisis , Antígeno Carcinoembrionario/análisis , Diferenciación Celular , Quimioterapia Adyuvante , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/cirugía , Resistencia a Antineoplásicos/genética , Fluorouracilo/efectos adversos , Genes p53 , Humanos , Leucovorina/administración & dosificación , Leucovorina/farmacología , Tablas de Vida , Mucinas/biosíntesis , Mucinas/genética , Metástasis de la Neoplasia , Proteínas de Neoplasias/genética , Estadificación de Neoplasias , Cuidados Paliativos , Pronóstico , Factores de Riesgo , Análisis de Supervivencia , Timidilato Sintasa/antagonistas & inhibidores , Timidilato Sintasa/metabolismoRESUMEN
The influence of MSI on treatment outcome of colorectal cancers remains unclear and deserves further investigation. We recruited 244 patients with stage IV sporadic colorectal cancers for our study, based on appropriate eligibility criteria. Patients were nonrandomly allocated to 2 treatment groups of either with or without high-dose 5-FU plus leucovorin chemotherapy (HDFL, 5-FU 2,600 mg/m(2) leucovorin 300 mg/m(2) maximum 500 mg). Each treatment group was further divided into 2 subgroups according to high-frequency MSI (MSI-H) status. MSI-H was defined as the appearance of MSI in at least 2 of the 5 examined chromosomal loci (BAT-25, BAT-26, D5S346, D2S123, D17S250). We compared clinicopathologic parameters, p53 overexpression and overall survival between the groups. In addition, 4 subgroups were identified as follows: MSI-H(+)HDFL(+), n = 35; MSI-H(-)HDFL(+), n = 134; MSI-H(+)HDFL(-), n = 17; MSI-H(-)HDFL(-), n = 58. There was no significant difference of background clinicopathologic data between the HDFL(+) and HDFL(-) treatment groups (p > 0.05). Survival analyses indicated that the patients of subgroup MSI-H(+)HDFL(+) survived significantly longer than those of subgroup MSI-H(-)HDFL(+), with median survival times of 24 (95% CI 20.2-27.9) and 13 (95% CI 11.6-14.4) months, respectively (p = 0.0001, log-rank test). In contrast, in patients without chemotherapy, the prognosis was poor irrespective of MSI status, with median survival times of 7.0 (95% CI 4.6-9.4) and 7.0 (95% CI 6.1-7.9) months in the MSI-H(+)HDFL(-) and MSI-H(-)HDFL(-) subgroups, respectively (p = 0.8205, log-rank test). MSI-H cancers responded significantly better to HDFL (p = 0.001), with a mean response rate of 65.71% (95% CI 49.98-81.44%) in subgroup MSI-H(+)HDFL(+) compared to 35.07% (95% CI 26.99-43.15%) in subgroup MSI-H(-)HDFL(+). There appeared to be no preferential metastatic site where response to HDFL can be predicted based on the MSI status of the primary tumor. Toxicity to HDFL was similarly minimal between MSI-H(+) and MSI-H(-) patients (p > 0.05). Multivariate analysis of all patients further indicated that MSI-H and chemotherapy were independent favorable prognostic parameters (p < 0.05). Thus, the better prognosis of stage IV sporadic colorectal cancers with MSI-H may be associated with better chemosensitivity, rather than lower aggressiveness in biologic behavior.