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BACKGROUND: Radical gastrectomy is composed of gastrectomy, lymph node dissection, and omentectomy. Total omentectomy (TO) is expected to reduce the incidence of peritoneal recurrence. We aimed to investigate the necessity of TO for advanced gastric cancer (AGC) with serosal invasion. METHODS: We retrospectively reviewed 310 patients who underwent radical gastrectomy with TO and 93 patients who underwent partial omentectomy (PO) for gastric cancer with serosal invasion between August, 2005 and December, 2017. Finally, 91 patients in the PO group and 91 in the TO group were enrolled based on a 1:1 propensity-score matching analysis. We evaluated surgical and oncological outcomes, including 5-year overall and recurrence-free survival rates. RESULTS: There was no statistically significant difference between the two groups in postoperative complications. Recurrence sites showed similar patterns in both groups, including peritoneal recurrence (PO vs. TO, 18.7% vs. 28.6%; p = 0.188). Five-year overall survival was better in the PO group (p = 0.018), while 5-year recurrence-free survival was similar in both groups (p = 0.066). CONCLUSION: TO might not be an essential part of preventing peritoneal recurrence for AGC with serosal invasion. PO could be considered a radical gastrectomy for T4a gastric cancer.
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Neoplasias Peritoneales , Neoplasias Gástricas , Humanos , Estudios Retrospectivos , Neoplasias Peritoneales/cirugía , Neoplasias Gástricas/patología , Peritoneo/cirugía , Peritoneo/patología , Membrana Serosa , GastrectomíaRESUMEN
BACKGROUND: Factors predicting postoperative complications after gastrectomy for elderly patients with gastric cancer have been analyzed in several previous studies. However, there is limited research available on risk factors related to long-term survival. AIMS: This study aimed to analyze factors affecting long-term survival after curative gastrectomy in elderly patients with advanced gastric cancer. METHODS: This study included patients aged > 75 years with histologically confirmed advanced gastric cancer stage II or greater. Before analysis, risk factors were categorized into four groups: baseline characteristics, underlying diseases, surgical and pathologic factors, and nutritional factors. RESULTS: The mean follow-up duration was 71.0 months. The 5-year overall survival and disease-specific survival rates were 51.5% and 58.3%, respectively. Kaplan-Meier curves showed that patients who were female and overweight had significantly longer survival rates than those who were male and underweight. Elderly patients who underwent a total gastrectomy had poorer survival rates than those who underwent a distal gastrectomy. Multivariate analysis demonstrated that tumor stage, extent of gastrectomy, overweight status and overall complication were independent risk factors for overall survival. DISCUSSION: Our study show that the overweight patients, the extent of gastrectomy, tumor stage and overall complications are significant risk factors affecting long-term survival. CONCLUSIONS: Therefore, surgeons may be cautious in performing total gastrectomy in elderly gastric cancer patients. Additionally, it is important to focus on improving nutritional status and mitigating overall complications.
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Neoplasias Gástricas , Anciano , Humanos , Masculino , Femenino , Resultado del Tratamiento , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Sobrepeso , Factores de Riesgo , Complicaciones Posoperatorias , Gastrectomía/efectos adversos , Tasa de Supervivencia , Estudios Retrospectivos , Estadificación de Neoplasias , PronósticoRESUMEN
BACKGROUND: We aimed to examine the technical and oncological safety of curative gastrectomy for gastric cancer patients who underwent liver transplantation. METHODS: In this study, we compared the surgical and oncological outcomes of two groups. The first group consisted of 32 consecutive patients who underwent curative gastrectomy for gastric cancer after liver transplantation (LT), while the other group consisted of 127 patients who underwent conventional gastrectomy (CG). In addition, a subgroup analysis was performed to evaluate the impact of the background differences and the surgical outcomes on the involvement of a specialized liver transplant surgery team. RESULTS: The mean operative time was significantly longer in the LT group (p < 0.05). Furthermore, there were more frequent cases of postoperative transfusion in the LT group compared to the CG group (p < 0.05). However, there were no significant differences in the overall complications between the groups (25.00 vs 23.62%, p = 0.874). The 5-year overall survival rates of the LT and CG groups were 76.7% and 90.1%, respectively (p < 0.05). The results of the subgroup analysis demonstrated no statistically significant difference in various early surgical outcomes, such as time to transfusion during surgery, first flatus, time to first soft diet, postoperative complications, hospital stay after surgery, and the number of harvested lymph nodes except for operation time. CONCLUSIONS: Despite one's medical history of undergoing LT, our study demonstrated that curative gastrectomy could be a surgically safe treatment for gastric cancer. However, further study should be conducted to identify the reason gastric cancer patients who underwent liver transplant surgery have lower overall survival rate.
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Laparoscopía , Trasplante de Hígado , Neoplasias Gástricas , Humanos , Trasplante de Hígado/efectos adversos , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Estudios Retrospectivos , Resultado del Tratamiento , Laparoscopía/métodos , Escisión del Ganglio Linfático/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Gastrectomía/efectos adversos , Gastrectomía/métodosRESUMEN
BACKGROUND: Knowledge on the optimal extent of lymphadenectomy among elderly patients with advanced gastric cancer is limited. This study was designed to compare standard D2 and limited lymphadenectomy for evaluating the appropriate extent of lymphadenectomy. PATIENTS AND METHODS: We retrospectively reviewed patient's data based on a prospectively collected gastric cancer registry. The inclusion criteria were age above 75 years and histologically confirmed stage II or more advanced gastric cancer. In this study, 103 patients who underwent limited lymph node dissection and 134 patients who underwent standard D2 lymph node dissection were included to evaluate surgical and oncological outcomes using propensity score matching (PSM) analysis. RESULTS: The mean age after PSM was approximately 78 years in both groups. The Charlson Comorbidity Index was 5.81 ± 0.87 and 5.75 ± 0.76, respectively, and 12.5% of the patients in both groups had American Society of Anesthesiologists scores of more than 3. The limited lymphadenectomy group showed a shorter operation time and fewer retrieved lymph. However, other surgical outcomes and pathological data were not significantly different between the groups. No postoperative mortality within 30 days was observed. There were no significant differences in overall complications between the groups. The 3-year overall survival rates of the limited and standard lymphadenectomy groups were 58.3% and 73.6%, respectively. The 3-year recurrence-free survival rate of the limited lymphadenectomy group was lower than that of the standard lymphadenectomy group; however, the difference was not statistically significant. CONCLUSIONS: Standard D2 lymphadenectomy has better oncological outcomes in elderly patients with advanced gastric cancer.
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Neoplasias Gástricas , Anciano , Gastrectomía/efectos adversos , Humanos , Escisión del Ganglio Linfático , Estudios Retrospectivos , Neoplasias Gástricas/patología , Tasa de SupervivenciaRESUMEN
BACKGROUND: A temperature-responsive hydrogel (PF-72; TGel Bio, Inc., Ltd, Seoul, Korea), developed as a sustained drug delivery device, can be mixed with ropivacaine to reduce pain in the incision area. The hydrogel is soluble at low temperatures (2-8 °C) and is converted into a gel at high temperatures (> 30 °C). We aimed to evaluate whether the administration of ropivacaine using PF-72 at incision sites reduces pain until 72 h postoperatively in patients undergoing laparoscopic stomach or colorectal surgery. METHODS: Patients were randomly assigned to the control group (0.75% ropivacaine) or PF-72 group (PF-72 mixed with 0.75% ropivacaine). Before surgical incision closure, 0.75% ropivacaine or PF-72 mixed with 0.75% ropivacaine was injected into the subcutaneous fat and muscle of all incisions. Postoperative pain was evaluated by the Numerical Rating Scale (NRS, 0 = no pain, 10 = most severe pain) for wound pain at 3, 6, 24, 48, and 72 h after the end of surgery. RESULTS: Ninety-nine patients (control, n = 51; PF-72, n = 48) were included in the analysis. The areas under the curve of NRS for wound pain until 72 h in the control group and the PF-72 group were 188.7 ± 46.1 and 135.3 ± 49.9 h, respectively (P < 0.001). The frequency of the administration of rescue analgesics in the general ward was similar between the two groups. CONCLUSION: PF-72 mixed with 0.75% ropivacaine reduced postoperative pain until 72 h in patients undergoing laparoscopic surgery. Although the study population was not large enough for safety evaluation, no adverse events associated with PF-72 were observed.
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Laparoscopía , Herida Quirúrgica , Amidas/uso terapéutico , Anestésicos Locales , Método Doble Ciego , Humanos , Hidrogeles/uso terapéutico , Laparoscopía/efectos adversos , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/etiología , Dolor Postoperatorio/prevención & control , Ropivacaína , Método Simple Ciego , TemperaturaRESUMEN
In wireless sensor networks, tree-based routing can achieve a low control overhead and high responsiveness by eliminating the path search and avoiding the use of extensive broadcast messages. However, existing approaches face difficulty in finding an optimal parent node, owing to conflicting performance metrics such as reliability, latency, and energy efficiency. To strike a balance between these multiple objectives, in this paper, we revisit a classic problem of finding an optimal parent node in a tree topology. Our key idea is to find the best parent node by utilizing empirical data about the network obtained through Q-learning. Specifically, we define a state space, action set, and reward function using multiple cognitive metrics, and then find the best parent node through trial and error. Simulation results demonstrate that the proposed solution can achieve better performance regarding end-to-end delay, packet delivery ratio, and energy consumption compared with existing approaches.
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Algoritmos , Tecnología Inalámbrica , Reproducibilidad de los Resultados , Simulación por ComputadorRESUMEN
Many applications are able to obtain enriched information by employing a wireless multimedia sensor network (WMSN) in industrial environments, which consists of nodes that are capable of processing multimedia data. However, as many aspects of WMSNs still need to be refined, this remains a potential research area. An efficient application needs the ability to capture and store the latest information about an object or event, which requires real-time multimedia data to be delivered to the sink timely. Motivated to achieve this goal, we developed a new adaptive QoS routing protocol based on the (m,k)-firm model. The proposed model processes captured information by employing a multimedia stream in the (m,k)-firm format. In addition, the model includes a new adaptive real-time protocol and traffic handling scheme to transmit event information by selecting the next hop according to the flow status as well as the requirement of the (m,k)-firm model. Different from the previous approach, two level adjustment in routing protocol and traffic management are able to increase the number of successful packets within the deadline as well as path setup schemes along the previous route is able to reduce the packet loss until a new path is established. Our simulation results demonstrate that the proposed schemes are able to improve the stream dynamic success ratio and network lifetime compared to previous work by meeting the requirement of the (m,k)-firm model regardless of the amount of traffic.
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To improve the packet delivery ratio in wireless sensor networks, many approaches such as multipath, opportunistic, and learning-based routing protocols have been proposed. However, the performance of the existing protocols are degraded under long-hop wireless sensor networks because the additional overhead is proportional to the number of hops. To deal with the overhead, we propose an opportunistic multipath routing that forecasts the required number of paths, as well as bifurcation based on opportunistic routing according to the reliability requirement. In the proposed scheme, an intermediate node is able to select a different node for each transmission and to handle path failure adaptively. Through a performance evaluation, we demonstrate that the proposed scheme achieves a higher packet delivery ratio and reduces the energy consumption by at least approximately 33% and up to approximately 65% compared with existing routing protocols, under the condition of an 80% link success ratio in the long-hop sensor network.
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Before discovering meaningful knowledge from big data systems, it is first necessary to build a data-gathering infrastructure. Among many feasible data sources, wireless sensor networks (WSNs) are rich big data sources: a large amount of data is generated by various sensor nodes in large-scale networks. However, unlike typical wireless networks, WSNs have serious deficiencies in terms of data reliability and communication owing to the limited capabilities of the nodes. Moreover, a considerable amount of sensed data are of no interest, meaningless, and redundant when a large number of sensor nodes is densely deployed. Many studies address the existing problems and propose methods to overcome the limitations when constructing big data systems with WSN. However, a published paper that provides deep insight into this research area remains lacking. To address this gap in the literature, we present a comprehensive survey that investigates state-of-the-art research work on introducing WSN in big data systems. Potential applications and technical challenges of networks and infrastructure are presented and explained in accordance with the research areas and objectives. Finally, open issues are presented to discuss promising directions for further research.
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BACKGROUND & AIMS: Early-onset gastric cancer, which develops in patients younger than most gastric cancers, is usually detected at advanced stages, has diffuse histologic features, and occurs more frequently in women. We investigated somatic genomic alterations associated with the unique characteristics of sporadic diffuse gastric cancers (DGCs) from younger patients. METHODS: We conducted whole exome and RNA sequence analyses of 80 resected DGC samples from patients 45 years old or younger in Korea. Patients with pathogenic germline mutations in CDH1, TP53, and ATM were excluded from the onset of this analysis, given our focus on somatic alterations. We used MutSig2CV to evaluate the significance of mutated genes. We recruited 29 additional early-onset Korean DGC samples and performed SNP6.0 array and targeted sequencing analyses of these 109 early-onset DGC samples (54.1% female, median age, 38 years). We compared the SNP6.0 array and targeted sequencing data of the 109 early-onset DGC samples with those from diffuse-type stomach tumor samples collected from 115 patients in Korea who were 46 years or older (late onset) at the time of diagnosis (controls; 29.6% female, median age, 67 years). We compared patient survival times among tumors from different subgroups and with different somatic mutations. We performed gene silencing of RHOA or CDH1 in DGC cells with small interfering RNAs for cell-based assays. RESULTS: We identified somatic mutations in the following genes in a significant number of early-onset DGCs: the cadherin 1 gene (CDH1), TP53, ARID1A, KRAS, PIK3CA, ERBB3, TGFBR1, FBXW7, RHOA, and MAP2K1. None of 109 early-onset DGC cases had pathogenic germline CDH1 mutations. A higher proportion of early-onset DGCs had mutations in CDH1 (42.2%) or TGFBR1 (7.3%) compared with control DGCs (17.4% and 0.9%, respectively) (P < .001 and P = .014 for CDH1 and TGFBR1, respectively). In contrast, a smaller proportion of early-onset DGCs contained mutations in RHOA (9.2%) than control DGCs (19.1%) (P = .033). Late-onset DGCs in The Cancer Genome Atlas also contained less frequent mutations in CDH1 and TGFBR1 and more frequent RHOA mutations, compared with early-onset DGCs. Early-onset DGCs from women contained significantly more mutations in CDH1 or TGFBR1 than early-onset DGCs from men. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times in patients with early-onset DGCs (hazard ratio, 3.4; 95% confidence interval, 1.5-7.7). RHOA activity was reduced by an R5W substitution-the RHOA mutation most frequently detected in early-onset DGCs. Silencing of CDH1, but not RHOA, increased migratory activity of DGC cells. CONCLUSIONS: In an integrative genomic analysis, we found higher proportions of early-onset DGCs to contain somatic mutations in CDH1 or TGFBR1 compared with late-onset DGCs. However, a smaller proportion of early-onset DGCs contained somatic mutations in RHOA than late-onset DGCs. CDH1 alterations, but not RHOA mutations, were associated with shorter survival times of patients, which might account for the aggressive clinical course of early-onset gastric cancer. Female predominance in early-onset gastric cancer may be related to relatively high rates of somatic CDH1 and TGFBR1 mutations in this population.
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Edad de Inicio , Cadherinas/genética , Proteínas Serina-Treonina Quinasas/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Neoplasias Gástricas/genética , Proteína de Unión al GTP rhoA/genética , Adulto , Antígenos CD , Femenino , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Mutación de Línea Germinal , Humanos , Masculino , Persona de Mediana Edad , Receptor Tipo I de Factor de Crecimiento Transformador beta , República de Corea , Factores Sexuales , Adulto JovenRESUMEN
BACKGROUND/AIM: The aim of this study was to establish an appropriate TNM staging system for early gastric cancer. METHODOLOGY: We evaluated 2124 patients who had undergone gastrectomy for early gastric cancer between 1989 and 2001. RESULTS: Using the seventh edition of the American Joint Committee on Cancer (AJCC) staging system, we found no significant differences in tumor recurrence and survival between N1 and N2 cancers or between N3a and N3b cancers, whereas the survival curves for N2 and N3 cancers were quite different. Similarly, using the classification in the sixth edition of the AJCC staging system, we found no significant difference in survival between the N2 and N3 cancer groups, whereas the survival curves for N1 versus N2 or N3 cancers were quite different. CONCLUSIONS: The classifications in the sixth and seventh editions of the AJCC staging system have a limitation for T1 gastric cancer (early gastric cancer).
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Adenocarcinoma/secundario , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias/normas , Neoplasias Gástricas/clasificación , Neoplasias Gástricas/patología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Gastrectomía , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Pronóstico , Tasa de SupervivenciaRESUMEN
BACKGROUND: Oral fluoropyrimidine S-1 contains tegafur, which is metabolized to 5-fluorouracil by cytochrome P450 2A6 (CYP2A6). We here examined associations between CYP2A6 polymorphisms and treatment outcomes of adjuvant S-1 in gastric cancer patients. METHODS: Patients received adjuvant S-1 (40 mg/m2 twice daily, days 1-28, every 6 weeks for eight cycles) after curative surgery for pathological stage II-III gastric cancer. We analyzed the wild-type allele (W) (CYP2A6*1) and four variant alleles (V) (CYP2A6*4, *7, *9, *10) that abolish or reduce this enzyme activity. RESULTS: Patients (n = 200) were enrolled between November 2007 and July 2013 with the following clinical characteristics: median age, 57 years (range, 32-83 years); 128 men, 72 women. With a median follow-up of 46.4 months, the 3-year relapse-free survival (RFS) and overall survival (OS) rates were 83.1 % (95 % CI, 77.7-88.5 %) and 94.8 % (95 % CI, 91.6-98.0 %), respectively. Genotype distributions were as follows: W/W (n = 49, 24.5 %), W/V (n = 94, 47.0 %), and V/V (n = 57, 28.5 %). Overall toxicity did not differ according to genotype for any grade (p = 0.612) or grade ≥3 (p = 0.143). However, RFS differed significantly according to CYP2A6 genotype. The 3-year RFS rates were 95.9 % for W/W, 83.1 % for W/V, and 72.5 % for V/V (p = 0.032). Carriers of W/V and V/V genotypes had a poorer RFS with a hazard ratio of 3.41 (95 % CI, 1.01-11.52; p = 0.049) and 4.03 (95 % CI, 1.16-13.93; p = 0.028), respectively, compared with the W/W genotype. CONCLUSIONS: CYP2A6 polymorphisms are not associated with toxicity of S-1 chemotherapy, but correlate with the efficacy of S-1 in the adjuvant setting for gastric cancer.
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Adenocarcinoma Mucinoso/genética , Biomarcadores de Tumor/genética , Carcinoma de Células en Anillo de Sello/genética , Citocromo P-450 CYP2A6/genética , Ácido Oxónico/uso terapéutico , Polimorfismo Genético/genética , Neoplasias Gástricas/genética , Tegafur/uso terapéutico , Adenocarcinoma Mucinoso/tratamiento farmacológico , Adenocarcinoma Mucinoso/patología , Adenocarcinoma Mucinoso/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/uso terapéutico , Carcinoma de Células en Anillo de Sello/tratamiento farmacológico , Carcinoma de Células en Anillo de Sello/patología , Carcinoma de Células en Anillo de Sello/cirugía , Quimioterapia Adyuvante , Combinación de Medicamentos , Femenino , Estudios de Seguimiento , Gastrectomía , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Estudios Retrospectivos , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugía , Tasa de SupervivenciaRESUMEN
BACKGROUND: Gastric carcinoma with lymphoid stroma (GCLS) is characterized by undifferentiated carcinoma mixed with prominent lymphoid infiltration. GCLS has unique clinicopathological features and a better prognosis compared to other types of gastric cancer. We analyzed the clinicopathological features of early GCLS in relation to lymph node metastasis (LNM). METHODS: We performed a retrospective analysis of 241 patients diagnosed with GCLS confined to the mucosa or the submucosa between March 1998 and December 2015. Their data were compared with those from 1219 patients who underwent resection for differentiated early gastric cancer (EGC). RESULTS: Of the 241 patients analyzed, 33 (13.7%) had intramucosal cancers and 208 (86.3%) had cancers that penetrated the submucosa. Compared to differentiated EGC, early GCLS was more prevalent in younger individuals and in men, tended to be proximally located, was highly associated with Epstein-Barr virus (EBV) infection (89.2%), and had a lower risk of LNM. The 5-year disease-specific survival rate of patients with early GCLS was 98.3% but depended significantly on LNM status (p < 0.001) and EBV infection status (p = 0.039). The risk of LNM from mucosal GCLS and submucosal GCLS was 0% [95% confidence interval (CI) 0-9.1] and 10% (95% CI 6.8-15.2), respectively. On multivariate analysis, LNM was found to be associated with tumor size (p = 0.022) and lymphovascular invasion (p = 0.002) in addition to tumor depth. CONCLUSIONS: Early GCLS has distinct clinicopathological features depending on age, sex, tumor location, EBV infection status, and LNM status. Tailored therapies, including endoscopic treatment, are needed based on the distinct clinicopathological features of early GCLS.
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Carcinoma/patología , Infecciones por Virus de Epstein-Barr/complicaciones , Mucosa Gástrica/patología , Neoplasias Gástricas/patología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Tasa de SupervivenciaRESUMEN
BACKGROUND: Endoscopic submucosal dissection (ESD) has become accepted as the standard treatment for early gastric cancer. However, comparative outcomes of ESD and surgery have not been evaluated for adenocarcinoma in the esophagogastric junction (EGJ). We investigated the long-term outcomes of ESD compared with those of surgery for adenocarcinoma in the EGJ. METHODS: Patients who underwent ESD or surgery for Siewert type II adenocarcinoma between 2005 and 2010 and who met the absolute and expanded criteria for endoscopic resection were eligible. Clinical features and treatment outcomes were retrospectively reviewed using medical records. RESULTS: Of the 79 patients included, 40 underwent ESD and 39 underwent surgery. During the median follow-up period of 60.9 months (range, 13.1-125.4 months), the 5-year overall survival rates were 93.9% and 97.3% for the ESD and surgery groups, respectively (p = 0.376). There were no gastric cancer-related deaths in either group. Adverse events occurred in 11 patients (13.9%) overall, and the incidence of treatment-related adverse events was similar between the two groups (10.0% vs. 17.9%, p = 0.308). CONCLUSIONS: ESD may be an effective alternative to surgery for the treatment of early gastric cancer in the EGJ based on the comparable long-term outcomes.
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Adenocarcinoma/cirugía , Neoplasias Esofágicas/cirugía , Unión Esofagogástrica/cirugía , Esofagoscopía/métodos , Mucosa Gástrica/cirugía , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Esofágicas/patología , Unión Esofagogástrica/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Tasa de SupervivenciaRESUMEN
OBJECTIVE: There is growing interest in the use of cuttlefish bone (CB) as a bone graft material. Silicon (Si) plays an important role in bone formation and calcification. This study aimed to prepare Si-substituted CB-derived hydroxyapatite (Si-CB-HAp) using a natural CB to improve the bioactivity for bone formation. MATERIALS AND METHODS: We prepared Si-HAp from CB (Si-CB-HAp) using a hydrothermal and solvothermal method. The microstructure and chemical composition were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectrometer (EDS). The bioactivity of the Si-CB-HAp was evaluated using human mesenchymal stem cells. Furthermore, the in vivo bone regeneration efficiency was evaluated using a rabbit calvarial defect model. RESULTS: Our results show that the Si content was 0.77 wt% in Si-CB-HAp, and its original microstructure was conserved. The presence of Si was shown to enhance cell proliferation and early cellular attachment of human mesenchymal stem cells. Additionally, results of alkaline phosphatase activity and real-time PCR for osteoblast marker genes show that Si substitution into CB-HAp enhanced osteoblast differentiation. In addition, in vivo bone defect healing experiments show that the formation of bone with Si-CB-HAp is higher than that with CB-HAp. CONCLUSION: These results indicate that Si-CB-HAp may potentially be used as a bone graft material to enhance bone healing.
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Materiales Biocompatibles/administración & dosificación , Regeneración Ósea/efectos de los fármacos , Durapatita/administración & dosificación , Animales , Adhesión Celular , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Decapodiformes , Humanos , Células Madre MesenquimatosasRESUMEN
OBJECTIVE: Rapid and stable fixation of dental implants is crucial for successful treatment. Herein, we examined whether the simultaneous treatment of titanium implants with ultraviolet (UV) and alendronate (ALN) synergistically improved the bone-to-implant contact. MATERIALS AND METHODS: We assessed the in vitro effects of UV radiation-treated (UV+/ALN-), ALN-soaked (UV-/ALN+), and UV radiation/ALN-treated (UV+/ALN+) titanium implants on cell proliferation, cytotoxicity, cell adhesion, and osteoblast differentiation using MG-63 osteoblast-like cells by the assays of MTS, live/dead, scanning electron microscopy (SEM), alkaline phosphatase (ALP) activity, and alizarin red S (AR-S) staining, respectively. Furthermore, in vivo bone formation at the bone-implant interface efficiency determined using a rabbit tibia implantation. Implants were divided into 3 experimental groups (UV+/ALN-, UV-/ALN+, UV+/ALN+) and the non-treated control (UV-/ALN-) group and transplanted into the proximal tibia of rabbits. At 1, 2, 4, and 8 weeks post-operation, bone formation at the bone-implant interface was evaluated by micro-computed tomography and histological analysis. RESULTS: MG-63 cells cultured on UV+/ALN+ implants showed significantly higher cell proliferation, ALP activity, and calcium mineralization than those cultured on other implants (P < 0.05). Furthermore, SEM observation showed the highest increase in cell attachment and growth on the UV+/ALN+ implants. In vivo, experimental groups at all time points showed greater peri-implant bone formation than the control group. At 8 weeks post-implantation, in the UV+/ALN+ group, significantly higher bone formation was observed than the UV+/ALN- or UV-/ALN+ group, respectively (P < 0.05). CONCLUSIONS: Treatment of titanium surfaces with UV and ALN may synergistically enhance osteoblastic differentiation and mineralization in vitro and enhance bone formation at the bone-implant interface in vivo. These data suggest that UV and ALN treatment may improve the osseointegration of titanium implants.
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Alendronato/farmacología , Interfase Hueso-Implante/efectos de la radiación , Implantes Dentales , Osteogénesis/efectos de los fármacos , Osteogénesis/efectos de la radiación , Rayos Ultravioleta , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/efectos de la radiación , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Células Cultivadas , Humanos , Osteoblastos/efectos de los fármacos , Osteoblastos/efectos de la radiaciónRESUMEN
Wireless Body Area Networks (WBANs) have attracted research interests from the community, as more promising healthcare applications have a tendency to employ them as underlying network technology. While taking design issues, such as small size hardware as well as low power computing, into account, a lot of research has been proposed to accomplish the given tasks in WBAN. However, since most of the existing works are basically developed by assuming all nodes in the static state, these schemes therefore cannot be applied in real scenarios where network topology between sensor nodes changes frequently and unexpectedly according to human moving behavior. However, as far as the authors know, there is no survey paper to focus on research challenges for mobility support in WBAN yet. To address this deficiency, in this paper, we present the state-of-the-art approaches and discuss the important features of related to mobility in WBAN. We give an overview of mobility model and categorize the models as individual and group. Furthermore, an overview of networking techniques in the recent literature and summary are compiled for comparison in several aspects. The article also suggests potential directions for future research in the field.
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Recently, various unicast routing protocols have been proposed to deliver measured data from the sensor node to the sink node within the predetermined deadline in wireless sensor networks. In parallel with their approaches, some applications demand the specific service, which is based on broadcast to all nodes within the deadline, the feasible real-time traffic model and improvements in energy efficiency. However, current protocols based on either flooding or one-to-one unicast cannot meet the above requirements entirely. Moreover, as far as the authors know, there is no study for the real-time broadcast protocol to support the application-specific traffic model in WSN yet. Based on the above analysis, in this paper, we propose a new (m, k)-firm-based Real-time Broadcast Protocol (FRBP) by constructing a broadcast tree to satisfy the (m, k)-firm, which is applicable to the real-time model in resource-constrained WSNs. The broadcast tree in FRBP is constructed by the distance-based priority scheme, whereas energy efficiency is improved by selecting as few as nodes on a tree possible. To overcome the unstable network environment, the recovery scheme invokes rapid partial tree reconstruction in order to designate another node as the parent on a tree according to the measured (m, k)-firm real-time condition and local states monitoring. Finally, simulation results are given to demonstrate the superiority of FRBP compared to the existing schemes in terms of average deadline missing ratio, average throughput and energy consumption.
RESUMEN
IMPORTANCE: Acute isovolemic anemia occurs when blood loss is replaced with fluid. It is often observed after surgery and negatively influences short-term and long-term outcomes. OBJECTIVE: To evaluate the efficacy and safety of ferric carboxymaltose to treat acute isovolemic anemia following gastrectomy. DESIGN, SETTING, AND PARTICIPANTS: The FAIRY trial was a patient-blinded, randomized, phase 3, placebo-controlled, 12-week study conducted between February 4, 2013, and December 15, 2015, in 7 centers across the Republic of Korea. Patients with a serum hemoglobin level of 7 g/dL to less than 10 g/dL at 5 to 7 days following radical gastrectomy were included. INTERVENTIONS: Patients were randomized to receive a 1-time or 2-time injection of 500 mg or 1000 mg of ferric carboxymaltose according to body weight (ferric carboxymaltose group, 228 patients) or normal saline (placebo group, 226 patients). MAIN OUTCOMES AND MEASURES: The primary end point was the number of hemoglobin responders, defined as a hemoglobin increase of 2 g/dL or more from baseline, a hemoglobin level of 11 g/dL or more, or both at week 12. Secondary end points included changes in hemoglobin, ferritin, and transferrin saturation levels over time, percentage of patients requiring alternative anemia management (oral iron, transfusion, or both), and quality of life at weeks 3 and 12. RESULTS: Among 454 patients who were randomized (mean age, 61.1 years; women, 54.8%; mean baseline hemoglobin level, 9.1 g/dL), 96.3% completed the trial. At week 12, the number of hemoglobin responders was significantly greater for ferric carboxymaltose vs placebo (92.2% [200 patients] for the ferric carboxymaltose group vs 54.0% [115 patients] for the placebo group; absolute difference, 38.2% [95% CI, 33.6%-42.8%]; P = .001). Compared with the placebo group, patients in the ferric carboxymaltose group experienced significantly greater improvements in serum ferritin level (week 12: 233.3 ng/mL for the ferric carboxymaltose group vs 53.4 ng/mL for the placebo group; absolute difference, 179.9 ng/mL [95% CI, 150.2-209.5]; P = .001) and transferrin saturation level (week 12: 35.0% for the ferric carboxymaltose group vs 19.3% for the placebo group; absolute difference, 15.7% [95% CI, 13.1%-18.3%]; P = .001); but there were no significant differences in quality of life. Patients in the ferric carboxymaltose group required less alternative anemia management than patients in the placebo group (1.4% for the ferric carboxymaltose group vs 6.9% for the placebo group; absolute difference, 5.5% [95% CI, 3.3%-7.6%]; P = .006). The total rate of adverse events was higher in the ferric carboxymaltose group (15 patients [6.8%], including injection site reactions [5 patients] and urticaria [5 patients]) than the placebo group (1 patient [0.4%]), but no severe adverse events were reported in either group. CONCLUSION AND RELEVANCE: Among adults with isovolemic anemia following radical gastrectomy, the use of ferric carboxymaltose compared with placebo was more likely to result in improved hemoglobin response at 12 weeks. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01725789.
Asunto(s)
Anemia/tratamiento farmacológico , Compuestos Férricos/uso terapéutico , Gastrectomía/efectos adversos , Hematínicos/uso terapéutico , Maltosa/análogos & derivados , Complicaciones Posoperatorias/tratamiento farmacológico , Adulto , Anciano , Anemia/sangre , Anemia/etiología , Femenino , Compuestos Férricos/efectos adversos , Hematínicos/efectos adversos , Hemoglobinas/metabolismo , Humanos , Inyecciones , Masculino , Maltosa/efectos adversos , Maltosa/uso terapéutico , Persona de Mediana Edad , Método Simple CiegoRESUMEN
Intensive research studies have revealed that fungal decolorization of dye wastewater is a promising replacement for the current process of dye wastewater decolorization. The authors isolated an Aspergillus sp. from the effluent of a textile industry area in Korea and assessed the effects of a variety of operational parameters on the decolorization of methyl red (MR) by this strain of Aspergillus sp. This Aspergillus sp. was then immobilized by entrapment in several polymeric matrices and the effects of operational conditions on MR decolorization were investigated again. The optimal decolorization activity of this Aspergillus sp. was observed in 1% glucose at a temperature of 37 °C and pH of 6.0. Furthermore, stable decolorization efficiency was observed when fungal biomass was immobilized into alginate gel during repeated batch experiment. These results suggest that the Aspergillus sp. isolated in Korea could be used to treat industrial wastewaters containing MR dye.