14 results on '"Jia-kui Zhang"'
Search Results
2. Identification and initial validation of maximal tumor area as a novel prognostic factor for overall and disease-free survival in patients with resectable colon cancer: a retrospective study.
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Fei-Long Ning, Wan-Jie Gu, Lin-Zheng Dai, Wan-Ying Du, Yong-Ji Zeng, Jia-Kui Zhang, Masanobu Abe, Yan-Long Liu, Rui Zhang, and Chun-Dong Zhang
- Abstract
Background: The tumor area may be a potential prognostic indicator. The present study aimed to determine and validate the prognostic value of tumor area in curable colon cancer. Methods: This retrospective study included a training and validation cohorts of patients who underwent radical surgery for colon cancer. Independent prognostic factors for overall survival (OS) and disease-free survival (DFS) were identified using Cox proportional hazards regression models. The prognostic discrimination was evaluated using the integrated area under the receiver operating characteristic curves (iAUCs) for prognostic factors and models. The prognostic discrimination between tumor area and other individual factors was compared, along with the prognostic discrimination between the tumor-node-metastasis (TNM) staging system and other prognostic models. Two-sample Wilcoxon tests were carried out to identify significant differences between the two iAUCs. A two-sided P < 0.05 was considered statistically significant. Results: A total of 3051 colon cancer patients were included in the training cohort and 872 patients in the validation cohort. Tumor area, age, differentiation, T stage, and N stage were independent prognostic factors for both OS and DFS in the training cohort. Tumor area had a better OS and DFS prognostic discrimination characteristics than T stage, maximal tumor diameter, differentiation, tumor location, and number of retrieved lymph nodes. The novel prognostic model of T stage + N stage + tumor area (iAUC for OS, 0.714, P < 0.001; iAUC for DFS, 0.694, P < 0.001) showed a better prognostic discrimination than the TNM staging system (T stage + N stage; iAUC for OS, 0.664; iAUC for DFS, 0.658). Similar results were observed in an independent validation cohort. Conclusions: Tumor area was identified as an independent prognostic factor for both OS and DFS in curable colon cancer patients, and in cases with an adequate number of retrieved lymph nodes. The novel prognostic model of combining T stage, N stage, and tumor area may be an alternative to the current TNM staging system. [ABSTRACT FROM AUTHOR]
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- 2023
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3. MiR-455-5p acts as a novel tumor suppressor in gastric cancer by down-regulating RAB18
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Dong-Qiu Dai, Yongshuang Li, Ji-chao Liu, Lei Wang, Baiqiang Sui, and Jia-kui Zhang
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Male ,0301 basic medicine ,Down-Regulation ,Apoptosis ,Biology ,03 medical and health sciences ,0302 clinical medicine ,Western blot ,Cell Movement ,Stomach Neoplasms ,Cell Line, Tumor ,Biomarkers, Tumor ,Genetics ,medicine ,Humans ,Neoplasm Invasiveness ,Luciferase ,Oncogene ,medicine.diagnostic_test ,Cell growth ,Cancer ,General Medicine ,Middle Aged ,medicine.disease ,Molecular biology ,Biomarker (cell) ,MicroRNAs ,030104 developmental biology ,rab GTP-Binding Proteins ,030220 oncology & carcinogenesis ,Cancer cell ,Female - Abstract
Aim To detect the potential regulation pathway of microRNA-455-5p (miR-455-5p) and RAB18, member RAS oncogene family (RAB18) in gastric cancer (GC) cells and tissues and discuss the clinical significance of miR-455-5p in GC genesis and progression. Methods Real-time PCR was used to measure mRNA level of miR-455-5p in GC, TargetScan and dual luciferase assay were used to predict and demonstrate the candidate target gene of miR-455-5p, Western blot were utilized to detect the protein level of RAB18. Cell function assays were also performed to determine the function of miR-455-5p in GC. Results miR-455-5p was reduced significantly in gastric cancer cells and tissues compared with the corresponding normal control, the lower expression of miR-455-5p was related to advanced clinical stage in gastric cancer, re-expression of miR-455-5p could inhibit human GC cell proliferation and invasion, overexpression of miR-455-5p could also promote GC cell apoptosis. Furthermore, we found that RAB18 was a candidate target of miR-455-5p. Re-expression of miR-455-5p could inhibit the protein level of RAB18. Conclusion MiR-455-5p might serve as a novel biomarker in gastric cancer by targeting RAB18.
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- 2016
4. Type D Personality in Gastric Cancer Survivors: Association With Poor Quality of Life, Overall Survival, and Mental Health
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Li-li Fang, De-wei Zhang, Dong-Qiu Dai, Jia-kui Zhang, Chun-Dong Zhang, Qiu Jin, Xiao-mei Wu, and Ji-chao Liu
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Male ,Personality Tests ,Emergency Medical Services ,medicine.medical_specialty ,Context (language use) ,Anxiety ,Hospital Anxiety and Depression Scale ,Type D Personality ,03 medical and health sciences ,0302 clinical medicine ,Cancer Survivors ,Quality of life ,Stomach Neoplasms ,Surveys and Questionnaires ,Internal medicine ,Humans ,Medicine ,Longitudinal Studies ,Prospective Studies ,030212 general & internal medicine ,Prospective cohort study ,General Nursing ,Aged ,Aged, 80 and over ,Depression ,business.industry ,Type D personality ,Confounding ,Cancer ,Middle Aged ,medicine.disease ,Survival Analysis ,Mental health ,Mental Health ,Anesthesiology and Pain Medicine ,030220 oncology & carcinogenesis ,Quality of Life ,Female ,Neurology (clinical) ,business ,Clinical psychology - Abstract
The associations between Type D personality and poor quality of life, overall survival, and mental health in gastric cancer survivors.The aim of this research was to explore quality of life (QoL), mental health status, Type D personality, symptom duration, and emergency admissions of Chinese gastric cancer patients, as well as the relationship between these factors.Eight hundred thirty eligible Chinese patients newly diagnosed with gastric cancer between July 2009 and July 2011 were enrolled in this prospective study. Type D personality was measured with the 14-item Type D Personality Scale (DS14). Mental health status was measured with the Hospital Anxiety and Depression Scale. The QoL outcomes were assessed longitudinally using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 and Quality of Life Questionnaire-STO22 at baseline and six months after diagnosis.The proportion of patients with symptom duration of more than one month and who were diagnosed after emergency admissions in the Type D group was significantly higher than that in the non-Type D personality group. At both of the time points, Type D patients reported statistically significant lower scores on role, emotional, cognitive, and social functioning (all Ps 0.001) functional scales, global health status/QoL scales (P 0.001), and worse symptom scores compared to patients without a Type D personality. During the six-month time frame, a higher percentage of patients in the Type D group demonstrated a considerable QoL deterioration. Clinically elevated levels of anxiety and depression were more prevalent in Type D than in non-Type D survivors (both Ps 0.001). There was a statistically significant difference in three-year overall survival between the patients in the Type D group and the non-Type D personality group.Type D personality is associated with poor QoL, three-year overall survival and mental health status among survivors of gastric cancer, even after adjustment of confounding background variables. The Type D personality group experienced increased levels of pain and fatigue compared to non-Type D patients. Type D personality might be a general vulnerability factor to screen for subgroups at risk of longer symptom duration and emergency admissions in clinical practice.
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- 2016
5. Modulation and performance tradeoffs for short-range non-line-of-sight ultraviolet communication
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Tianfeng Wu, Jianshe Ma, Ping Su, and Jia-kui Zhang
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Computer science ,Bandwidth (signal processing) ,02 engineering and technology ,Channel models ,medicine.disease_cause ,01 natural sciences ,Light scattering ,010309 optics ,Non-line-of-sight propagation ,symbols.namesake ,020210 optoelectronics & photonics ,Gaussian noise ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Bit error rate ,Electronic engineering ,symbols ,medicine ,Ultraviolet ,Data transmission - Abstract
The non-line-of-sight ultraviolet single-scatter approximate model is usually used to study the channel characteristics and system performance due to its simplification. In this paper, a performance evaluation system based on the approximate model is established, which includes four aspects, namely, packet error rate, average transmitting power, bandwidth utilizing efficiency and data transmission rate. Under the condition that Gaussian noise distribution is considered in channel model, the performance of different modulation schemes is evaluated. Finally, give the performance metrics that the system can achieve within 100 meters.
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- 2017
6. Downregulation of ADAMTS8 by DNA Hypermethylation in Gastric Cancer and Its Clinical Significance
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Dong-Qiu Dai, Jia-kui Zhang, Junzhe Jin, Hongbin Zhang, Jing Chen, Chun-Dong Zhang, and Xin Li
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Male ,0301 basic medicine ,Article Subject ,Down-Regulation ,lcsh:Medicine ,General Biochemistry, Genetics and Molecular Biology ,Metastasis ,03 medical and health sciences ,ADAMTS Proteins ,0302 clinical medicine ,Stomach Neoplasms ,Cell Line, Tumor ,Humans ,Medicine ,RNA, Messenger ,Aged ,Regulation of gene expression ,General Immunology and Microbiology ,business.industry ,ADAMTS ,digestive, oral, and skin physiology ,lcsh:R ,General Medicine ,Methylation ,DNA Methylation ,Middle Aged ,medicine.disease ,Molecular biology ,digestive system diseases ,Angiogenesis inhibitor ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,CpG site ,030220 oncology & carcinogenesis ,DNA methylation ,ADAMTS8 ,Azacitidine ,Female ,business ,Research Article - Abstract
A disintegrin and metallopeptidase with thrombospondin motif type 8 (ADAMTS8), a member of the ADAMTS family, was discovered as a novel angiogenesis inhibitor. We analyzed the expression and methylation of ADAMTS8 in primary gastric tumors and gastric cancer cell lines. We also examined the relationship between ADAMTS8 expression and methylation and clinicopathologic features. The results showed that the significant downregulation of ADAMTS8 mRNA expression was observed in gastric cancer cell lines and tissues, and its expression was related to invasive depth and lymph node metastasis. CpG was hypermethylated in gastric cancer cell lines MKN45, MGC803, and BGC823, as well as primary gastric cancer specimens. ADAMTS8 mRNA expression was significantly lower in methylated primary gastric tumors. A significant association was found between ADAMTS8 methylation status and lymph node metastasis in primary gastric cancer. Moreover, ADAMTS8 expression was upregulated in the gastric cancer cell lines MGC803, BGC823, and MKN45 after treatment with 5-aza-2′-deoxycytidine. Thus, our results demonstrate that expression of ADAMTS8 mRNA is significantly decreased and DNA methylation is frequent in gastric cancer. ADAMTS8 hypermethylation is associated with decreased expression in gastric cancer and may play an important role in the invasion and metastasis of gastric cancer.
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- 2016
7. Type D personality is associated with delaying patients to medical assessment and poor quality of life among rectal cancer survivors
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Jia-kui Zhang, Dong-Qiu Dai, Ji-chao Liu, Qiu Jin, Xiao-mei Wu, De-wei Zhang, Chun-Dong Zhang, and Li-li Fang
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Male ,medicine.medical_specialty ,Colorectal cancer ,Anxiety ,Hospital Anxiety and Depression Scale ,03 medical and health sciences ,Type D Personality ,0302 clinical medicine ,Quality of life ,Internal medicine ,Surveys and Questionnaires ,medicine ,Humans ,030212 general & internal medicine ,Longitudinal Studies ,Survivors ,Psychiatry ,Depression (differential diagnoses) ,Aged ,Demography ,Aged, 80 and over ,business.industry ,Depression ,Rectal Neoplasms ,Type D personality ,Confounding ,Gastroenterology ,Middle Aged ,medicine.disease ,Mental health ,humanities ,Mental Health ,030220 oncology & carcinogenesis ,Quality of Life ,Female ,medicine.symptom ,business - Abstract
The aim of this research was to explore quality of life (QoL), mental health status, type D personality, symptom duration, and emergency admissions of Chinese rectal cancer patients as well as the relationship between these factors. Type D personality was measured with the 14-item Type D Personality Scale (DS14). Mental health status was measured with the Hospital Anxiety and Depression Scale (HADS). The QoL outcomes were assessed longitudinally using the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires at the baseline and 6 months after diagnosis. Of the 852 survivors who responded (94 %), 187 (22 %) had a type D personality. The proportion of patients with duration of symptoms >1 month and being diagnosed after emergency admissions in type D group is significantly higher than that in non-type D group. At both of the time points, type D patients reported statistically significant lower scores on most of the functional scales, global health status/QoL scales, and worse symptom scores compared to patients without a type D personality. At the 6-month time point, a higher percentage of patients in the type D group demonstrated QoL deterioration. Clinically elevated levels of anxiety and depression were more prevalent in type D than in non-type D survivors. Type D personality was associated with poor QoL and mental health status among survivors of rectal cancer, even after adjustment for confounding background variables. Type D personality might be a general vulnerability factor to screen for subgroups at risk for longer symptom duration and emergency admissions in clinical practice.
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- 2015
8. Factors associated with delaying medical assessment of patients and impacting the prognosis of rectal cancer
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Li-li Fang, Chun-Dong Zhang, Xiao-mei Wu, Dong-Qiu Dai, Jia-kui Zhang, and Ji-chao Liu
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Male ,Cancer Research ,medicine.medical_specialty ,Emergency Medical Services ,Delayed Diagnosis ,Time Factors ,Referral ,Epidemiology ,Colorectal cancer ,Surgical oncology ,Internal medicine ,Emergency medical services ,Medicine ,Humans ,Prospective cohort study ,Survival rate ,Referral and Consultation ,Aged ,Neoplasm Staging ,Aged, 80 and over ,business.industry ,Rectal Neoplasms ,Public Health, Environmental and Occupational Health ,Emergency department ,Length of Stay ,Middle Aged ,medicine.disease ,Prognosis ,Combined Modality Therapy ,Surgery ,Hospitalization ,Survival Rate ,Oncology ,Female ,Medical assessment ,business ,Follow-Up Studies - Abstract
The aims of this study were (a) to compare the clinical presentations and outcomes of patients referred to the hospital from the emergency department (ED) and those referred from non-ED facilities in a Chinese population and (b) to identify the factors influencing delays in medical assessment and prognosis for patients with rectal cancer (RC). Eligible Chinese patients newly diagnosed with RC, admitted to the hospital from the ED, or referred from non-ED sources between 1 January 2008 and 31 December 2009 were enrolled in this prospective study. Associations between symptoms, symptom duration, tumor stage at diagnosis, and 3-year survival were proposed to identify factors associated with delay in the diagnosis of RC and emergency admission. Compared with patients in the non-ED group, patients in the ED group had a significantly longer hospital stay, greater in-hospital mortality, a higher proportion of advanced stage tumor, lower rate of undergoing potentially curative surgery, and a higher proportion of symptom duration longer than 1 month. There was a statistically significant difference in the 3-year overall survival between the patients who underwent emergency operation within 24 h of admission and the patients presenting as emergency who underwent an operation longer than 24 h from admission to operation. Patients who endured symptoms longer than 1 month had a significantly higher proportion of emergency admissions, higher proportion of advanced stage tumor, and lower rate of undergoing potentially curative surgery compared with patients whose symptom duration was less than 1 month. In conclusion, (a) ED referral patients endured significantly longer symptom duration before diagnosis. (b) Emergency operation within 24 h of admission was an independent prognostic indicator of overall survival in patients with RC. A two-stage approach for the management of patients with RC who presented as emergency could enable patients to be transferred to a specialist department of surgical oncology for a definitive radical oncological operation and improve the prognosis.
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- 2015
9. Neoadjuvant chemotherapy for nonmetastatic esophago-gastric adenocarcinomas: a systematic review and meta-analysis
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Yongji Zeng, Chun-Dong Zhang, Jia-kui Zhang, Dong-Qiu Dai, Hong-Wu Li, and Zhe-Ming Zhao
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Oncology ,Cancer Research ,medicine.medical_specialty ,Esophageal Neoplasms ,medicine.medical_treatment ,Adenocarcinoma ,Disease-Free Survival ,law.invention ,Randomized controlled trial ,law ,Stomach Neoplasms ,Internal medicine ,medicine ,Humans ,Perioperative Period ,Survival rate ,Neoadjuvant therapy ,Randomized Controlled Trials as Topic ,Chemotherapy ,business.industry ,General Medicine ,Odds ratio ,Perioperative ,medicine.disease ,Neoadjuvant Therapy ,Treatment Outcome ,Chemotherapy, Adjuvant ,Meta-analysis ,business - Abstract
A systematic review and meta-analysis was performed to investigate the efficacy of neoadjuvant chemotherapy for nonmetastatic esophago-gastric adenocarcinomas.Electronic databases were searched systematically from January 1980 to July 2012 and a total of 2,587 patients from 17 randomized controlled trials were subjected to meta-analysis. The odds ratios (ORs) for overall survival (OS) and progression-free survival (PFS) were calculated.Seventeen randomized controlled trials were obtained and various comparisons of treatment approaches were performed. Randomized controlled trials detected no differences in these comparisons: R0 resection for neoadjuvant chemotherapy versus none; Preoperative chemotherapy versus surgery alone: 3-year OS, 5-year OS, 5-year OS in Europe, 3-year PFS; Preoperative chemotherapy plus postoperative chemotherapy versus postoperative chemotherapy: 1-year OS, 5-year OS; Preoperative chemotherapy versus preoperative chemoradiotherapy: 3-year OS. Randomized controlled trials detected significant differences in these comparisons: Preoperative chemotherapy plus postoperative chemotherapy versus surgery alone: 3-year and 5-year PFS, 5-year OS; Subgroup analysis examining preoperative chemotherapy versus surgery alone: 5-year OS in Asia; Preoperative chemotherapy versus postoperative chemotherapy: 1-year OS.The current limited evidence suggests that preoperative chemotherapy can be applied to patients with nonmetastatic esophago-gastric adenocarcinomas (specifically, advanced esophago-gastric cancer). However, the results should be interpreted with caution because of the statistically low power and the heterogeneity among study designs; therefore, our results need validations in future studies.
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- 2013
10. Up-regulation of CRKL by microRNA-335 methylation is associated with poor prognosis in gastric cancer.
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Jia-kui Zhang, Yong-shuang Li, Chun-dong Zhang, and Dong-qiu Dai
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STOMACH cancer treatment , *MICRORNA , *CARCINOGENESIS , *CANCER invasiveness , *POLYMERASE chain reaction , *ONCOGENES - Abstract
Background: MicroRNAs have been suggested to play a vital role in regulating carcinogenesis, tumor progression and invasion. MiR-335 is involved in suppressing metastasis and invasion in various human cancers. However, the mechanisms responsible for the aberrant expression of miR-335 in gastric cancer (GC) remain unknown. Methods: Expression of miR-335 in four GC cell lines and 231 GC tissues was determined by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). DNA methylation status in the CpG islands upstream of miR-335 in GC cell lines and tissues was determined by methylation-specific PCR and bisulfite sequence-PCR. The effects of the demethylating agent 5-aza-2'-deoxycytidine on cell proliferation, apoptosis, cell cycle, migration, and invasion were investigated in GC cell lines. Results: Cancer-specific methylation was detected in the upstream CpG-rich regions of miR-335, which dramatically silenced its transcriptional activity in GC cell lines and tissues. Low levels of miR-335 expression and high levels of miR-335 methylation in GC tissues were associated with poor clinical features and prognosis. Restoration of miR-335 expression in GC cells promoted cell apoptosis, inhibited tumor cell migration, invasion, and proliferation, and arrested the cell cycle at G0/G1 phase. Overexpression of miR-335 significantly reduced the activity of a luciferase reporter containing the 3' untranslated region of V-crk avian sarcoma virus CT10 oncogene homolog-like (CRKL). Conclusions: MiR-335 functions as a tumor suppressor and may be silenced by promoter hypermethylation. It plays a role in inhibiting tumor cell migration, invasion, and proliferation, arresting the cell cycle at G0/G1 phase, and promoting apoptosis in GC cells through targeting CRKL. [ABSTRACT FROM AUTHOR]
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- 2017
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11. Extended antimicrobial prophylaxis after gastric cancer surgery: A systematic review and meta-analysis
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Chun-Dong Zhang, Dong-Qiu Dai, Yongji Zeng, Jing Chen, Hong-Wu Li, Jia-kui Zhang, and Zhen Li
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medicine.medical_specialty ,medicine.medical_treatment ,education ,Treatment outcome ,Anastomotic Leak ,Intraoperative Period ,Postoperative Complications ,Anti-Infective Agents ,Stomach Neoplasms ,medicine ,Humans ,Intensive care medicine ,Randomized Controlled Trials as Topic ,business.industry ,digestive, oral, and skin physiology ,Gastroenterology ,Reproducibility of Results ,Bacterial Infections ,General Medicine ,Antimicrobial ,Wound infection ,digestive system diseases ,Treatment Outcome ,Meta-analysis ,Wound Infection ,Gastrectomy ,business ,Cancer surgery ,Meta-Analysis - Abstract
To investigate the efficacy of extended antimicrobial prophylaxis (EAP) after gastrectomy by systematic review of literature and meta-analysis.Electronic databases of PubMed, Embase, CINAHL, the Cochrane Database of Systematic Reviews, the Cochrane Controlled Trials Register and the China National Knowledge Infrastructure were searched systematically from January 1980 to October 2012. Strict literature retrieval and data extraction were carried out independently by two reviewers and meta-analyses were conducted using RevMan 5.0.2 with statistics tools risk ratios (RRs) and intention-to-treat analyses to evaluate the items of total complications, surgical site infection, incision infection, organ (or space) infection, remote site infection, anastomotic leakage (or dehiscence) and mortality. Fixed model or random model was selected accordingly and forest plot was conducted to display RR. Likewise, Cochrane Risk of Bias Tool was applied to evaluate the quality of randomized controlled trials (RCTs) included in this meta-analysis.A total of 1095 patients with gastric cancer were enrolled in four RCTs. No statistically significant differences were detected between EAP and intraoperative antimicrobial prophylaxis (IAP) in total complications (RR of 0.86, 95%CI: 0.63-1.16, P = 0.32), surgical site infection (RR of 1.97, 95%CI: 0.86-4.48, P = 0.11), incision infection (RR of 4.92, 95%CI: 0.58-41.66, P = 0.14), organ or space infection (RR of 1.55, 95%CI: 0.61-3.89, P = 0.36), anastomotic leakage or dehiscence (RR of 3.85, 95%CI: 0.64-23.17, P = 0.14) and mortality (RR of 1.14, 95%CI: 0.10-13.12; P = 0.92). Likewise, multiple-dose antimicrobial prophylaxis showed no difference compared with single-dose antimicrobial prophylaxis in surgical site infection (RR of 1.10, 95%CI: 0.62-1.93, P = 0.75). Nevertheless, EAP showed a decreased remote site infection rate compared with IAP alone (RR of 0.54, 95%CI: 0.34-0.86, P = 0.01), which is the only significant finding. Unfortunately, EAP did not decrease the incidence of surgical site infections after gastrectomy; likewise, multiple-dose antimicrobial prophylaxis failed to decrease the incidence of surgical site infection compared with single-dose antimicrobial prophylaxis.We recommend that EAP should not be used routinely after gastrectomy until more high-quality RCTs are available.
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- 2013
12. Factors associated with delaying medical assessment of patients and impacting the prognosis of rectal cancer.
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Jia-kui Zhang, Li-li Fang, Xiao-mei Wu, Ji-chao Liu, Chun-dong Zhang, and Dong-qiu Dai
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- 2015
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13. Improved Particle Swarm Optimization Using Wolf Pack Search.
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Hao-ran Chen, Li-jie Cui, Qing Guo, and Jia-kui Zhang
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- 2019
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14. Up-regulation of CRKL by microRNA-335 methylation is associated with poor prognosis in gastric cancer
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Dong-Qiu Dai, Yongshuang Li, Chun-Dong Zhang, and Jia-kui Zhang
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0301 basic medicine ,Cancer Research ,Biology ,medicine.disease_cause ,Methylation ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,microRNA ,medicine ,Genetics ,MiR-335 ,Cell growth ,MicroRNA ,Cell cycle ,Prognosis ,Demethylating agent ,CRKL ,030104 developmental biology ,chemistry ,Oncology ,Tumor progression ,030220 oncology & carcinogenesis ,DNA methylation ,Cancer research ,Carcinogenesis ,Primary Research ,Gastric cancer - Abstract
Background MicroRNAs have been suggested to play a vital role in regulating carcinogenesis, tumor progression and invasion. MiR-335 is involved in suppressing metastasis and invasion in various human cancers. However, the mechanisms responsible for the aberrant expression of miR-335 in gastric cancer (GC) remain unknown. Methods Expression of miR-335 in four GC cell lines and 231 GC tissues was determined by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). DNA methylation status in the CpG islands upstream of miR-335 in GC cell lines and tissues was determined by methylation-specific PCR and bisulfite sequence-PCR. The effects of the demethylating agent 5-aza-2′-deoxycytidine on cell proliferation, apoptosis, cell cycle, migration, and invasion were investigated in GC cell lines. Results Cancer-specific methylation was detected in the upstream CpG-rich regions of miR-335, which dramatically silenced its transcriptional activity in GC cell lines and tissues. Low levels of miR-335 expression and high levels of miR-335 methylation in GC tissues were associated with poor clinical features and prognosis. Restoration of miR-335 expression in GC cells promoted cell apoptosis, inhibited tumor cell migration, invasion, and proliferation, and arrested the cell cycle at G0/G1 phase. Overexpression of miR-335 significantly reduced the activity of a luciferase reporter containing the 3′ untranslated region of V-crk avian sarcoma virus CT10 oncogene homolog-like (CRKL). Conclusions MiR-335 functions as a tumor suppressor and may be silenced by promoter hypermethylation. It plays a role in inhibiting tumor cell migration, invasion, and proliferation, arresting the cell cycle at G0/G1 phase, and promoting apoptosis in GC cells through targeting CRKL.
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