Research and application of tongue and face diagnosis based on deep learning.

Objective: To explore the technical research and application characteristics of deep learning in tongue-facial diagnosis. Methods: Through summarizing the merits and demerits of current image processing techniques used in the traditional medical tongue and face diagnosis, the research status of deep learning in tongue image preprocessing, segmentation, and classification was analyzed and reviewed, and the algorithm was compared and verified with the real tongue and face image. Images of the face and tongue used for diagnosis in conventional medicine were systematically reviewed, from acquisition and pre-processing to segmentation, classification, algorithm comparison, result from analysis, and application. Results: Deep learning improved the speed and accuracy of tongue and face diagnostic image data processing. Among them, the average intersection ratio of U-net and Seg-net models exceeded 0.98, and the segmentation speed ranged from 54 to 58 ms. Conclusion: There is no unified standard for lingual-facial diagnosis objectification in terms of image acquisition conditions and image processing methods, thus further research is indispensable. It is feasible to use the images acquired by mobile in the field of medical image analysis by reducing the influence of environmental and other factors on the quality of lingual-facial diagnosis images and improving the efficiency of image processing.

[Structural changes of gut microbiota after gastric bypass in obese patients with type 2 diabetes].

OBJECTIVE: To investigate the structural changes inintestinal flora and metabolic changes in type 2 diabetic patients with obesity(BMI≥40 kg/m2)by sequencing the 16S rRNA genes. METHODS: Stool samples were collected from 4 diabetic patients before and after gastric bypass surgery for extraction of the total DNA. The diversity of the intestinal flora in the samples was investigated by 16S rRNA sequencing. After surgery, the changes in glucose and lipid metabolism were evaluated in the patients, and the changesin body mass index (BMI) and waist to hip ratio were assessed at 3 month intervals. RESULTS: After gastric bypass, the patient's BMI, waist to hip ratio, glucose metabolism and lipid metabolism gradually recovered the normal levels. The proportion of Bacteroidetesis increased and the proportions of Firmicutes and Proteobacteria decreased in the intestinal bacteria after the surgery. CONCLUSION: Gastric bypass surgery can effectively alleviate the condition of obese patients with type 2 diabetes and improve the composition of the intestinal flora.

[Efficacy of three-dimensional laparoscopic total thyroidectomy combined with central lymph node dissection for thyroid cancer and its effect on inflammatory responses of the patients].

OBJECTIVE: To analyze the effect of three-dimensional (3D) laparoscopic total thyroidectomy combined with central lymph node dissection for thyroid cancer and its effect on the inflammatory response of the patients. METHODS: The clinical data were analyzed in 90 patients with thyroid cancer undergoing radical thyroidectomy at our hospital between September, 2013 to April, 2016, including 30 receiving 3D laparoscopic surgeries, 30 with 2D laparoscopic surgeries and 30 with open surgeries. The surgical data, postoperative adverse reactions and the impact of the surgeries on the inflammatory responses of the patients were compared among the 3 groups. RESULTS: Compared with the open surgery and 2D laparoscopic surgery, 3D laparoscopic surgery was associated with lowered blood loss during the surgery and a lowered incidence of adverse reactions. The operation time in 3D group was significantly shorter than that in 2D group (P<0.05), but the total hospitalization expenses were similar between the two groups. The postoperative drainage volume did not differ significantly between the 3D group and the other two groups. The postoperative hospital stay, number of lymph nodes dissected, positivity rate of lymph nodes and the inflammatory response showed no significant differences among the 3 groups (P>0.05). CONCLUSION: 3D laparoscopic total thyroidectomy combined with central lymph node dissection is safe and effective and reduces intraoperative blood loss and perioperative adverse reactions without significant influence on inflammatory response in patients with thyroid cancer.

Gap junction composed of connexin43 modulates 5­fluorouracil, oxaliplatin and irinotecan resistance on colorectal cancers.

Chemotherapy is one of the most commonly used therapeutic strategies for metastatic colon cancer. However, the development of resistance to chemotherapeutic agents limits their application in clinical use. The underlying mechanisms of this resistance development require further elucidation. The current study investigated the effects of connexin43 (Cx43) gap junctions on 5­fluorouracil (5­FU), oxaliplatin and irinotecan in colon cancer cells. Three different methods were used to manipulate Cx43 gap junction function: i) Cell culture at different densities; ii) pretreatment with a Cx43 specific inhibitor or enhancer; and iii) Cx43 gene knock­down. Results indicated that the cell toxicity of 5­FU, oxaliplatin and irinotecan was cell density­dependent, which was mediated by gap junctions. Downregulation of Cx43 gap junction functioning attenuated 5­FU, oxaliplatin and irinotecan toxicity in colon cancer cells, which was increased in cells treated with a Cx43 gap junction function enhancer. Thus, the results of the present study suggest that resistance to 5­FU, oxaliplatin and irinotecan in colon cancer cells was relative to Cx43 expression loss as cancer developed, which may indicate a novel basis for therapeutic strategy development to combat drug resistance in numerous cell types, in addition to colon cancer cells.

Preoperative platelet to lymphocyte ratio is a valuable prognostic biomarker in patients with colorectal cancer.

OBJECTIVES: Recent studies suggest that an elevated preoperative platelet to lymphocyte ratio (PLR) may be considered a poor prognostic biomarker in patients with colorectal cancer (CRC). The aim of this study was to evaluate the prognostic impact of PLR in patients with CRC. METHODS: We enrolled 1314 patients who underwent surgery for CRC between 2005 and 2011. Preoperative PLR level was stratified into quintiles for Kaplan-Meier analysis and multivariable Cox proportional hazard regression models. RESULTS: Higher PLR quintiles were significantly associated with poorer overall survival (P = 0.002). Multivariate analysis showed that PLR was an independent risk factor for overall survival (OS) (P = 0.034). Patients in PLR quintile 5 had lower overall survival than in quintile 1 (hazard ratio (HR) = 1.701, 95% confidence interval (CI): 1.267-2.282, P < 0.001). Although patients in PLR quintile 5 had significantly lower disease-free survival (DFS) than in quintile 1 (HR = 1.522, 95% CI: 1.114-2.080, P = 0.008), this association was not significant after multivariable adjustment (P = 0.075). In the subgroup analysis, PLR remained an independent factor in terms of advanced tumor stage (III, IV), male sex, carcinoembryonic antigen (≤ 5 ng/ml), age (> 65 years) and body mass index (≤ 25) (P < 0.05 for all measurements). The results remained unchanged when the PLR was analyzed as a dichotomous variable by applying different cut-off values of 150, 185, 220. CONCLUSIONS: Elevated preoperative PLR was independently associated with an increased risk of mortality in patients with CRC. The utility of PLR may help to improve prognostic predictors.

Neoadjuvant chemotherapy (NCT) plus targeted agents versus NCT alone in colorectal liver metastases patients: A systematic review and meta-analysis.

PURPOSE: To assess the efficacy of neoadjuvant chemotherapy (NCT) plus targeted agents versus NCT alone for the treatment of colorectal liver metastases (CRLM) patients. METHODS: Trials published between 1994 and 2015 were identified by an electronic search of public databases (MEDLINE, EMBASE, Cochrane library). All clinical studies were independently identified by two authors for inclusion. Demographic data, treatment regimens, objective response rate (ORR), hepatic resection and R0 hepatic resection rate were extracted and analyzed using Comprehensive MetaAnalysis software (Version 2.0). RESULTS: A total of 40 cohorts with 2099 CRLM patients were included: 962 patients were treated with NCT alone, 602 with NCT plus anti-epidermal growth-factor receptor (EGFR)-monoclonal antibodies (MoAbs) and 535 with NCT plus bevacizumab. Pooled ORR was significantly higher for NCT plus bevacizumab or anti-EGFR-MoAbs than NCT alone [relative risk (RR) 1.53, 95% CI 1.30-1.80; p < 0.001; RR 1.53, 95% CI: 1.27-1.83, p < 0.001; respectively]. NCT plus bevacizumab significantly improved R0 hepatic resection rate (RR 1.61, 95% CI: 1.27-2.04, p < 0.001), but not for overall hepatic resection rate (RR 1.26, 95% CI: 0.81-1.94, p = 0.30). While hepatic resection and R0 hepatic resection rate was comparable between NCT plus anti-EGFR-MoAbs and NCT alone (p = 0.42 and p = 0.37, respectively). CONCLUSIONS: In comparison with NCT alone, NCT plus bevacizumab significantly improve ORR and R0 hepatic resection rate but not for hepatic resection rate. Our findings support the need to compare NCT plus bevacizumab with NCT alone in the neoadjuvant setting in large prospective trials due to its higher hepatic resection rate and R0 hepatic resection rate in CRLM patients.

Association between the receptor for advanced glycation end products gene polymorphisms and cancer risk: a systematic review and meta-analysis.

PURPOSE: Polymorphisms in the receptor for advanced glycation end products (RAGE) gene may influence the risk of cancer, but the results are inconsistent. Therefore, we performed a systematic review to identify statistical evidence of the association between the 3 polymorphisms rs2070600 G/S (82G>S), rs1800624 T/A ( -374 T>A) and rs1800625C/T (-429 C>T) and the risk of cancer. METHODS: We searched PubMed database (http://www.ncbi. nlm.nih.gov/pubmed/), EMBASE database (http://www.elsevier.com/online-tools/embase ) and China National Knowledge Infrastructure (CNKI) database (http://www.cnki.net/) until Aug 30, 2014 to identify eligible studies. RESULTS: The pooled analysis revealed positive association between RAGE rs2070600 polymorphism and cancer risk in all genetic models (homozygous: OR=1.831, 95%CI: 1.548-2.166, p<0.001, allele: OR=1.321, 95%CI: 1.164-1.499, p<0.001, heterozygous: OR=1.42, 95%CI:1.126-1.792, p=0.003, dominant: OR=1.499, 95%CI: 1.200-1.874 ; p<0.001, recessive: OR=1.376, 95%CI: 1.197-1.583, p<0.001). We failed to get an effective conclusion about the association between the rs1800624 and rs1800625 polymorphisms and cancer risk in overall comparison. But in subgroup analysis, the rs1800624 polymorphism significantly increased lung cancer susceptibility in the homozygous model (OR=1.486, 95%CI:1.147-1.924, p=0.003) and the allele model (OR=1.15, 95%CI:1.029-1.285, p=0.014), but most likely contributed to decreased susceptibility to breast cancer in the allele model (OR=0.791 95%CI: 0.648-0.965, p=0.021), the heterozygous model (OR=0.733, 95%CI:0.577-0.931, p=0.011) and the dominant model (OR=0.741, 95%CI:0.588-0.934, p=0.011). No significant association was found between RAGE rs1088625 polymorphism and cancer risk in Caucasians, but these results should be interpreted with caution. CONCLUSION: The polymorphism of rs2070600 in the RAGE gene may increase the susceptibility to several human cancers, especially to lung cancer and to Asians. The rs1800264 most likely contributes to decreased susceptibility to breast cancer but increased susceptibility to lung cancer. However, large-scale studies involving various cancer types and different populations are needed for a precise conclusion.

A novel, intelligent, pressure-sensing colostomy plug for reducing fecal leakage.

This study aims to describe and report the effectiveness of a novel, pressure-sensing colostomy plug for reducing fecal leakage. Nine miniature Tibetan pigs, aged 6-8 months, were given colostomies and divided into three groups (n = 3 each group). A novel pressure-sensing colostomy plug was placed in each pig and set to indicate when intestinal pressures of either 5, 10, or 15 mm Hg, respectively, were reached. When the pressure thresholds were reached, the animals' bowels were examined for the presence of stool and/or stomal leakage, and the data were recorded at weeks 1, 4, and 8 after surgery. The colostomy plug calibrated to 15 mm Hg pressure demonstrated the greatest accuracy in predicting the presence of stool in the bowels of study animals, averaging >90% sensitivity. In general, the sensitivity for predicting the presence of stool did not vary significantly over time, though there was a slight increase in accuracy in the 5 mm Hg group at later time-points. The sensitivity for predicting stool in the bowel did not change significantly over time in any of the three groups. Stomal leakage was found to be inversely proportional to the pressure-sensor setting, in that the 15 mm Hg group exhibited the greatest amount of leakage. This difference, however, was found to be significant only at week 1 postsurgery. The intelligent, pressure-sensing colostomy plug was able to accurately predict the presence of stool in the bowel and maintain continence, allowing negligible leakage.

Polyamidoamine dendrimer liposome-mediated survivin antisense oligonucleotide inhibits hepatic cancer cell proliferation by inducing apoptosis.

Polyamidoamine dendrimer (PAMAM) is a new nanometer material, which can transfer the target genes to cells with high efficiency and lower toxicity. This study aims to evaluate antitumor effects of survivin antisense oligonucleotide (survivin-asODN) (carried by polyamidoamine dendrimer liposome) on hepatic cancer in nude mice. Hepatic cancer model was established by injecting SMMC-7721 cells subcutaneously into flanks of nude mice. Polyamidoamine dendrimer and liposome were mixed with survivin-asODN, respectively. The shape and size of complex were observed by transmission electron microscope, and zeta potential was measured by an analytical tool. Encapsulation efficiency and DNA loading level were determined by an ultraviolet spectrophotometer in centrifuging method. Expression of survivin in transplant tumor was measured by Western blotting. No significant difference appeared for diameter and envelopment ratio between PAMAM liposome-survivin-asODN and PAMAM-survivin-asODN (P > 0.05). Both zeta potential and transfection efficiency in PAMAM liposome-survivin-asODN were higher than that in PAMAM-survivin-asODN complex (P < 0.05). Expression of survivin protein and weight of tumors in transplanted tumors in PAMAM liposome-survivin-asODN group was less than that in PAMAM-survivin-asODN group (P < 0.05). Cell apoptosis rate in PAMAM liposome-survivin-asODN group was higher than that of PAMAM-survivin-asODN group (P < 0.05). In conclusion, polyamidoamine dendrimer liposome can deliver survivin-asODN into hepatic transplanted tumor cells effectively. Ployamidoamine dendrimer liposome-mediated survivin-asODN can inhibit hepatic cell proliferation by inducing apoptosis.

Asiatic acid promotes p21(WAF1/CIP1) protein stability through attenuation of NDR1/2 dependent phosphorylation of p21(WAF1/ CIP1) in HepG2 human hepatoma cells.

Previous studies have suggested anti-tumor effects of asiatic acid in some human cancer cell lines. This agent is reported to increase the levels of p21WAF1/CIP1 in human breast cancer cell lines. However, the molecular mechanisms have not been established. Here we report that asiatic acid up-regulates p21WAF1/CIP1 protein expression but not the level of p21WAF1/CIP1 mRNA in HepG2 human hepatoma cells. Furthermore, we found that the asiatic acid induced increase of p21WAF1/CIP1 protein was associated with decreased phosphorylation (ser-146) of p21WAF1/CIP1. Knockdown of NDR1/2 kinase, which directly phosphorylates p21WAF1/CIP1 protein at ser-146 and enhances its proteasomal degradation, increased the levels of p21WAF1/CIP1 protein and eliminated the regulation of p21WAF1/ CIP1 stability by asiatic acid. At the same time, the expression of NDR1/2 kinase decreased during treatment with asiatic acid in HepG2 cells. Moreover, asiatic acid inhibited the proliferation of HepG2 cells, this being attenuated by knockdown of p21WAF1/CIP1. In conclusion, we propose that asiatic acid inhibits the expression NDR1/2 kinase and promotes the stability of p21WAF1/CIP1 protein through attenuating NDR1/2 dependent phosphorylation of p21WAF1/CIP1 in HepG2 cells.

Adenovirus-mediated tissue-targeted expression of the CDglyTk gene for the treatment of breast cancer.

The aim of this study was to evaluate the selective killing efficacy of adenovirus (Ad)-mediated double suicide genes driven by the kinase domain-containing receptor (KDR) promoter in human breast cancer cells and vascular endothelial cells. Two Ad-mediated double suicide gene systems [with the two suicide genes, thymidine kinase (TK) and cytosine deaminase (CD)] with the KDR promoter (Ad-KDRP-CDglyTK) and the cytomegalovirus (CMV) promoter (Ad-CMV-CDglyTK) were established and transfected into the KDR-expressing MCF7 human breast cancer, EC304 human vascular endothelial and LS174T human colon carcinoma, which does not express KDR, cell lines. The selective killing efficiency and specificity of the double suicide gene system were measured in vitro by the analysis of cellular proliferation and assayed in vivo by subcutaneous injection of MCF7 cells into nude mice. The microvessel density (MVD) in the transplanted tumor was determined by immunohistochemical staining of CD34 cells. Our results showed that the transgenic CDglyTK genes were expressed in three cell lines (MCF7, ECV304 and LS174T) infected with Ad-CMV-CDglyTK. However, of the cells infected with Ad-KDRP-CDglyTK, the transgenic CDglyTK gene was only expressed in the KDR-expressing MCF7 and ECV304 cells, but not in the KDR-deficient LS174T cells. Cell proliferation was significantly reduced in a dose-dependent manner by pre-treatment with ganciclovir (GCV) and 5-fluorocytosine (5-FC) in MCF7 and ECV304 cells with transfected KDRP-CDglyTK genes and the three cell lines transfected with the CMV-CDglyTK genes. Similar results were not observed in the LS174T cells with transfected KDRP-CDglyTK genes. The results of this study show that the tumor-targeted expression of CDglyTK driven by the KDR promoter has a high specificity and performance. The killing effect of the CD/TK fusion gene in the target cells was significantly increased compared with the single suicide gene. The cell cycle of MCF7 and ECV304 cells transfected with KDRP-CDglyTK genes was arrested at the S phase following treatment with the prodrugs. The tumors formed by the MCF7 cells with the double suicide gene system were much smaller and the MVD of the tumor tissue was significantly decreased compared with the control. This study demonstrates that tumor­targeted expression of the CDglyTK gene driven by the KDR promotor may be a novel strategy for the gene therapy of human breast cancer.

[Clinical application of 64-slice computed tomographic angiography-based virtual colonoscopy in the diagnosis of colonic tumors].

OBJECTIVE: To investigate the clinical value of 64-slice computed tomographic angiography (CTA)-based virtual colonoscopy in the diagnosis of colonic tumors. METHODS: Philips/Brilliance 64 CT volumetric scanning was performed in 8 patients with colonic cancer and 2 with colonic polypi identified by postoperative pathological examination. Mimics software was used for surface rendering of the intestine with the Marching Cubes algorithm for 3-dimensional (3D) virtual endoscope (VE) reconstruction and CTA-based 3D reconstruction of the large intestine and the surrounding structures. The location, volume and appearance of the lesions displayed by the virtual techniques were compared with the pathological results. RESULTS: The 3D reconstruction was successfully completed in all the 10 cases, and the imaging diagnoses showed a total match with the pathological diagnoses. No significant differences were found between virtual endoscopy and CT virtual endoscopy. Virtual colonoscopy combined with digital model reconstruction provided valuable information for accurate identification of the position of the lesions and the complex adjacent anatomical structures. CONCLUSION: Virtual colonoscopy based on 64-slice CTA, when combined with 3D reconstruction technique, allows accurate display of the colonic lesions and potential metastasis, which can be crucial for clinical staging and surgical planning of colonic cancer.

[Colonic sac duct for first-stage repair of colon anastomotic leakage in miniature pigs].

OBJECTIVE: To study the efficacy, safety and reliability of colonic sac duct for first-stage repair of colorectal anastomotic leakage. METHODS: An animal model of colon anastomotic leakage was established in 30 Tibet miniature pigs, which were randomly divided into treatment group and control group (n=15). Colon anastomotic leakage in the treatment group was repaired using the colonic sac duct, while the control group received conventional surgical repair. At 7, 14, and 21 days after the surgery, the healing of the anastomotic leakage was evaluated by examining the bursting pressure, tissue microvessel density and hydroxyproline content at the anastomosis. RESULTS: Using the colonic sac duct, the anastomotic leakage was successfully repaired without death of the pigs or the occurrence of intestinal stenosis or necrosis. At 7 and 14 days after the surgery, the bursting pressure, hydroxyproline contents, and microvessel density in the treatment groups were higher than those in the control group, but such difference was not found at 21 days. CONCLUSION: Colonic sac duct allows effective repair of colon anastomotic leakage, and is especially useful for leakage lasting for 48-72 h complicated by severe abdominal infection.

In vitro and in vivo assessment of an intelligent artificial anal sphincter in rabbits.

Artificial sphincters have been developed for patients with fecal incontinence, but finding a way to make such sphincters more "intelligent" remains a problem. We assessed the function of a novel intelligent artificial anal sphincter (IAAS) in vitro and in vivo in rabbits. After the prosthesis was activated, rabbits were continent of feces during 81.4% of the activation time. The fecal detection unit provided 100% correct signals on stool in vitro and 65.7% in vivo. The results indicated that the IAAS could efficiently maintain continence and detect stool; however, the IAAS is still in the preliminary experimental stage and more work is needed to improve the system.

[Inhibitory effect of recombinant adenovirus containing CDglyTK double suicide gene driven by KDR promoter on human stomach adneocarcinoma SCG7901 cells in vitro].

OBJECTIVE: To study the inhibitory effect of adenovirus-mediated fusion gene system driven by KDR promoter on the proliferation of human gastric adneocarcinoma SCG7901 cells and observe the bystander effect in vitro. METHODS: SCG7901, ECV304 and HepG2 cells were infected with Ad-KDR-CDglyTK and Ad-CMV-CDglyTK at a multiplicity of infection (MOI) of 100, and the infection efficiency and the mRNA expressions of the transferred fusion gene were investigated. GCV and/or 5-FC at different concentrations were added into the culture medium of the infected cells to observe the targeted antitumor effect and bystander effect of CDglyTK suicide gene driven by KDR promoter. RESULTS: With the MOI of the adenovirus of 100, the fluorescence emitted by green fluorescent protein (GFP) was observed in 95% of the infected SCG7901, ECV304 and HepG2 cells. All the cells infected by Ad-CMV-CDglyTK and SCG7901 and ECV304 cells infected by Ad-KDR-CDglyTK were highly sensitive to the prodrugs. In comparison, HepG2 cells infected with Ad-KDR-CDglyTK did not show much sensitivity to the two prodrugs. Following treatment with the prodrugs at the same concentration, the infected SCG7901 and ECV304 cells exhibited gradually lowered survival rates as the culture time was prolonged, whereas the transgenic HepG2 cells showed no such time-dependent changes. When the non-infected cells were cocultured with the transgenic cells, the bystander effect of CDglyTK gene was observed, which increased with the ratio of the transgenic cells. In these mixed cell culture systems, GCV and 5-FC showed obvious synergetic effect in suppressing the cell survival. CONCLUSION: The CDglyTK fusion gene system driven by KDR promoter can inhibit the proliferation of SCG7901 and ECV304 cells with obvious bystander effect in vitro. The combination of the prodrugs produces obvious synergetic effect against the cell survival.

[Selective cytotoxic effect of lentivirus-mediated double suicide gene transfer on human gastric adneocarcinoma cells].

OBJECTIVE: To study the selective cytotoxic effect of lentivirus-mediated double suicide gene (CD/TK) against human gastric carcinoma cells SGC-7901 in vitro. METHODS: SGC-7901 cells were infected with FGW-KDRP-CD/TK vector and the infection efficiency was observed under a fluorescence microscope. The morphological changes of the infected cells were observed by Giemsa staining. Flow cytometry (FCM) was employed for cell cycle analysis, and the expression of CD/TK was detected by RT-PCR. The infected cells were then treated with the prodrugs ganciclovir (GCV) and/or 5-fluorocytosine (5-FC) at different concentrations, and the cytotoxic effects were evaluated using MTT method. RESULTS: The infection efficiency of the lentiviral vector in SGC-7901 cells increased with the titer of the virus, which produced no significant effect on the cancer cell morphology in vitro or on the percentages of G0-G1, G2-M and S phase cells (P>0.05). RT-PCR demonstrated the expression of CD/TK gene in SGC-7901 cells infected by FGW-KDRP-CD/TK. The infected cells were highly sensitive to the prodrugs with a dose-dependent cytotoxic effect within a specific concentration range of the drugs, whereas the non-infected cells were not sensitive to the prodrugs. Combined use of the two prodrugs produced an obviously stronger inhibitory effect than either of the them (P<0.05). When combined, GCV and 5-FC at the concentration of 0.1+40, 1+80, 10+160, and 100+320 mg/L demonstrated a synergetic effect with a CDI<1. CONCLUSION: Lentivirus-mediated CD/TK fusion gene system can selectively kill gastric cancer cells, and the two prodrugs show a synergistic cytotoxic effect.

[A double suicide gene system driven by KDR promoter selectively kills human colon adneocarcinoma SW480 cells].

OBJECTIVE: To study the selective killing effect of adenovirus (Ad)-mediated double suicide gene system driven by the KDR promoter (KDR-CDglyTK) on human colon adneocarcinoma SW480 cells. METHODS: KDR-expressing SW480 cells and LS174T cells that did not express KDR were infected by KDR-CDglyTK, and the infection efficiency and the expression of CDglyTK in the cells were detected by RT-PCR. The infected cells were treated with the prodrugs 5-FC and GCV at different concentrations, and the cell-killing effects and bystander effects were evaluated by MTT method. DNA content and the cell cycle changes in SW480 cells were detected by flow cytometry. RESULTS: The expression of green fluorescent protein (GFP) was observed in 95% of the infected SW480 and LS174T cells with a multiplicity of infection (MOI) of 100. RT- PCR demonstrated that the product of CD/TK gene existed in SW480 cells infected by Ad- KDR- CD/TK, but not in infected LS174 cells. The infected SW480 cells exhibited high sensitivity to the prodrugs, but the infected LS174T cells did not (P<0.01). Bystander effects of the double suicide gene system were observed in the coculture of the infected and non-infected SW480 cells. At the MOI of 100, treatment of the infected cells with the prodrugs resulted in increased cell percentage in G(0)-G(1) phase and decreased percentage in S phase and the prodrug-treated cells showed an apoptotic peak in flow cytometry. CONCLUSION: CDglyTK fusion gene system driven by the KDR promoter selectively kills and induces the apoptosis of the KDR-CDglyTK SW480 cells.

[Effect of adenovirus-mediated CD/TK double suicide gene system on colorectal cancer growth and cytokines in the tumor microenvironment in mice].

OBJECTIVE: To evaluate the effect of adenovirus-mediated CD/TK double suicide gene system on tumor growth and cytokine levels in the tumor microenvironment in mice bearing transplanted colorectal cancer. METHODS: CT26 cells were implanted subcutaneously into 30 Balb/c mice, which were subsequently randomized into the control (n=15) and experimental group (n=15). After the tumor formation, CD/TK double suicide gene system was administered for tumor treatment, and the changes in the tumor volume, tumor inhibition rate, and levels of cytokines in the tumor microenvironment were investigated. RESULTS: CD/TK double suicide gene system resulted in a significant inhibition of the tumor growth and significantly increased levels of such cytokines as IL-2, IL-10, TNFalpha and IFNgamma in the tumor microenvironment. CONCLUSION: CD/TK double suicide gene system produces significant tumor inhibition effect and causes obvious cytokine changes in the tumor microenvironment in mice bearing transplanted colorectal cancer.

[Establishment and evaluation of rabbit model of fecal incontinence].

OBJECTIVE: To establish and evaluate a rabbit model of fecal incontinence. METHODS: Twelve normal adult male New Zealand rabbits were randomly divided into experimental group and control group. The nerve innervating the external anal sphincter, namely the fourth sacral nerve, was functionally located and selectively damaged with local injection of 50 g/L ropivacaine in the experimental group, and normal saline injection was administered in the control group. The changes in the resting anal pressure was examined before and after the surgery, and the electromyogram (EMG) of the external anal sphincter was recorded for comparison with the pathological changes of the fourth sacral nerve. RESULTS: Compared with the control group, the experimental group exhibited significantly decreased resting anal pressure after the surgery. The EMG of the experimental group showed abnormal nerve conduction velocity of the fourth sacral nerve, suggesting successful nerve block. Transmission electron microscope revealed irreversible pathological changes in the ultrastructure of the axons of the fourth sacral nerve. CONCLUSION: This method allows successful establishment of fecal incontinence in rabbits, which facilitates further in vivo study of artificial sphincters for treatment of anal incontinence.

[Effect of KDR recombinant adenovirus containing double suicide gene on the proliferation of human colon adneocarcinoma SW620 cells].

OBJECTIVE: To study the effect of adenovirus (Ad)-mediated fusion gene system driven by the KDR promoter on the proliferation of human colon adenocarcinoma SW620 cells. METHODS: The KDR-expressing SW620 cells and LS174T cells not expressing KDR were both infected with AdEasy-KDR-CDglyTK followed by treatment with the prodrugs 5-FC and/or ganciclovir at different concentrations. The effect of the transfection on the cell proliferation was evaluated. RESULTS: The expression of green fluorescent protein (GFP) was observed in 95% of the infected SW620 and LS174T cells with a multiplicity of infection (MOI) of 100. Significant difference was not founded in the growth of SW620 and LS174T cells with or without the transfection. The infected SW620 cells exhibit high sensitivity to the prodrugs, but the infected LS174T cells did not (P<0.01). The CDglyTK fusion gene produced much stronger killing effect of on the target cells than either of the single suicide genes (P<0.01). CONCLUSION: CDglyTK fusion gene system driven by the KDR promoter selectively kills the KDR-CDglyTK SW620 cells and inhibits the cell proliferation.