Clinical study of different bowel preparations on changes of gut flora in patients undergoing colorectal resection / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To compare the impact of traditional and fast bowel preparation on the changes of gut flora in the patients following colorectal resection.</p><p><b>METHODS</b>Sixty patients undergoing colorectal resection from March 2010 to March 2011 in the Nanfang Hospital were randomly divided into the control group(n=27, 3 days of bowel preparation) and the experimental group(n=33, 1 day of bowel preparation). Fresh feces were collected before bowel preparation and on the first defecation after surgery. The postoperative changes in gut flora and septic complications were observed.</p><p><b>RESULTS</b>Gut flora disturbance was found in both groups. The postoperative population of Bifidobacterium and Lactobacillus decreased significantly(P<0.05), and the decrease was more significant in the experimental group compared to the control group(P<0.05), while E.coli and Staphylococcus were much higher than the preoperative level(P<0.05), which was more significant in the control group. The incidence of postoperative infection was 9.1%(3/33) in the experimental group, which was significantly lower than 29.6%(8/27) in the control group(P<0.05).</p><p><b>CONCLUSION</b>Fast bowel preparation is effective in reducing gut flora disturbance and the incidence of postoperative infection.</p>

MicroRNA-221 promotes colon carcinoma cell proliferation in vitro by inhibiting CDKN1C/p57 expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the regulatory effect of microRNA-221 (MIR221) on CDKN1C/p57 expression in colon carcinoma cells in vitro.</p><p><b>METHODS</b>Caco2 cells were treated with or without anti-p57-siRNA prior to the addition of pre-MIR221 or anti-MIR221. The MIR221 expression pattern was detected by real-time RT-PCR, and the mRNA and protein levels of CDKN1C/p57 expression were detected using semi-quantitative RT-PCR and Western blotting. Caco2 cell proliferation following the treatment was detected with MTT assay. CDKN1C/p57 3'-UTR fragment was amplified by PCR from the genome DNA of human colon and inserted into a luciferase reporter plasmid. The luciferase reporter plasmid construct was then transfected into Caco2 cells along with pre-MIR221 or anti-MIR221, and the luciferase activity in the transfected cells was detected.</p><p><b>RESULTS</b>MIR221-specific inhibitor significantly up-regulated CDKN1C/p57 protein expression in Caco2 cells (P<0.01). Anti-MIR221 could markedly inhibit Caco2 cell proliferation, and the inhibitory effect was obviously abolished by pretreatment with anti-p57-siRNA, suggesting that the inhibition was mediated by CDKN1C/p57 (P<0.01). A significant increase of luciferase activity was detected in Caco2 cells co-transfected with the luciferase reporter plasmid construct and anti-MIR221 (P<0.01).</p><p><b>CONCLUSIONS</b>MIR221 can interact with the target site on the 3'-UTR of CDKN1C/p57 mRNA to inhibit CDKN1C/p57 expression by post-transcriptional gene silencing to promote colon carcinoma cell proliferation, suggesting the value of MIR221 as a potential target for treatment of colon carcinoma.</p>

MicroRNA-221 controls CDKN1C/P57 expression in human colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of microRNA-221 (miR-221) and CDKN1C/P57 in colorectal carcinoma (CRC) and adjacent non-cancerous tissues. The effect of miR-221-specific inhibitor on cell proliferation and apoptosis in CRC cells was also assessed.</p><p><b>METHODS</b>The expression of miR-221 was detected by real-time RT-PCR. CDKN1C/P57 mRNA and corresponding protein expression pattern were detected by semi-quantitative RT-PCR and Western-blot. The specific 2'-methoxy-modified RNA oligonucleotide of miR-221(miRNA inhibitor,anti-miR-221) was designed, synthesized and transfected into Caco2 cell by liposome. Finally, the status of CRC cell proliferation and apoptosis were detected by MTT assay and flow cytometry.</p><p><b>RESULTS</b>The expression of miR-221 was significantly up-regulated in CRC tissues as compared to the adjacent non-cancerous tissues(2.041±1.401 vs. 0.806±0.341, P<0.01). There was no significant difference in CDKN1C/P57 mRNA expression between CRC and non-cancerous tissues, whereas CDKN1C/P57 protein markedly decreased in CRC (3.019±1.708 vs. 0.972±0.316, P<0.01). miR-221-specific inhibitor significantly enhanced CDKN1C/P57 protein expression, inhibited proliferation of CRC cells and induced apoptosis of CRC cells(P<0.01).</p><p><b>CONCLUSIONS</b>miR-221 inhibits CDKN1C/P57 expression by post-transcriptional gene silencing to promote CRC development and progression. miR-221-specific inhibitor potentially inhibits the growth of CRC cells. Therefore, it may be a new target for the biologic therapy for CRC.</p>

Effect of miR-221-specific inhibitor on the proliferation and apoptosis of human colorectal carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate miRNA-221 expression in human colorectal carcinoma (CRC) cells and the effects of miR-221-specific inhibitor on the proliferation and apoptosis of CRC cells.</p><p><b>METHODS</b>Four human CRC cell lines (HT-29, Lovo, SW-480, and CaCO2) were examined for miRNA-221 expression using real-time Q-PCR. The specific 2,-methoxy-modified RNA oligonucleotides of miR-221 (anti-miR-221) were synthesized and transfected into Caco2 cells via liposome, and the changes in the expression of miR-221 in the cells were detected by real-time Q-PCR. The proliferation and apoptosis of the transfected CRC cells were detected using MTT assay and flow cytometry.</p><p><b>RESULTS</b>The 4 human CRC cells showed significantly upregulated expression of miR-221 compare with HUVECs (P<0.01). The miR-221-specific inhibitor, anti-miR-221, significantly inhibited the expression of miR-221 in Caco2 cells and suppressed the cell proliferation, causing also obvious cell apoptosis (P<0.01).</p><p><b>CONCLUSION</b>The miR-221-specific inhibitor shows potent inhibitory effect on the growth of CRC cells, suggesting its value as a potential anti-tumor candidate for treatment of CRC.</p>

Effects of FOLFOX4 neoadjuvant chemotherapy on the non-tumoral liver in patients with metastatic colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of FOLFOX4 neoadjuvant chemotherapy on the non-tumoral liver in patients with metastatic colorectal carcinoma.</p><p><b>METHODS</b>A large series of surgically resected liver metastases(n=42) was selected and the morphological changes were examined by light and electron microscope. The mRNA and protein levels of connective tissue growth factor (CTGF) expression were detected by semi-quantitative RT-PCR and Western blotting analysis.</p><p><b>RESULTS</b>Twelve (63.2%) of the 19 post-chemotherapy liver resection specimens had sinusoidal dilatation and hemorrhage. In contrast, 23 livers treated by surgery alone remained normal. Neoadjuvant chemotherapy could significantly enhance the mRNA and protein levels of CTGF expression in hepatic stellate cells.</p><p><b>CONCLUSION</b>Systemic FOLFOX4 neoadjuvant chemotherapy in metastatic colorectal carcinoma frequently causes morphological injuries involving hepatic microvasculature and induces CTGF expression in hepatic stellate cells to participate in hepatic fibrosis.</p>

Expression of R-spondin1 in intestinal epithelium of mice with intestinal ischemia-reperfusion injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of R-spondin1 (RSpo1) in the intestinal epithelium of mice with intestinal ischemia-reperfusion injury and explore its significance.</p><p><b>METHODS</b>Fifty normal male Kunming mice were randomized into sham-operated group (n=10) and intestinal ischemia-reperfusion injury group (n=40), and in the latter group, the mice were subjected to 20-min intestinal mesenteric artery occlusion followed by reperfusion for 6, 12, 24, or 48 h. Enzyme-linked immunosorbent assay (ELISA) and RT-PCR were used to detect intestinal RSpo1 expression of the mice.</p><p><b>RESULTS</b>The results of RT-PCR and ELISA showed that RSpo1 expression was significantly decreased in mice at 6 h of reperfusion following the intestinal ischemia (P<0.05), and increased gradually with prolonged repersuion time, reaching the peak level at 24 h (P<0.05). The expression underwent rapid decrease afterwards to a significantly lower level than that in the control group at 48 h (P<0.05).</p><p><b>CONCLUSION</b>Intestinal ischemia-reperfusion injury may inhibit expression of RSpo1 in the early stage, and enhance its expression in the middle stage. RSpo1 can promote proliferation and differentiation of intestinal epithelial stem cells and plays an important role in the repair intestinal mucosal damage.</p>

Screening peptides binding specifically to large intestinal cancer LoVo cells from phage random peptide library / 南方医科大学学报

<p><b>OBJECTIVE</b>To screen the polypeptides specifically binding to human large intestinal cancer LoVo cells from a phage-displayed peptide library for potential use as targeting vectors for large intestinal cancer therapy.</p><p><b>METHODS</b>With the LoVo cells as the target cells and human normal large intestinal mucosal epithelial cells as the absorber cells for subtraction biopanning from a c7c phage-display peptide library, the positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence detection. The amino acid sequences of the identified peptides were deduced by DNA sequencing.</p><p><b>RESULTS</b>After 3 rounds of screening, 5 positive phage clones showing specific binding to LoVo cells and containing conserved motif RPMP were obtained from the 20 randomly selected clones.</p><p><b>CONCLUSION</b>Specific peptide against large intestinal cancer cells can be obtained from a phage-display peptide library for use as potential vectors for targeting therapy of large intestinal cancer.</p>

Dynamic observation of intestinal epithelial stem cells of small intestine during the injured-repaired progress induced by 5-FU / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes of intestinal epithelial stem cells during the injured-repaired progress induced by 5-FU.</p><p><b>METHODS</b>Fifty adult C57BL/6J mice were enrolled in this study, 40 of them were intraperitoneally injected with 5-FU (30 mg per kg of body weigh) for five days, and 10 of them intraperitoneally injected with PBS as control. At day 1, 3, 5, 7 after treatment, the mice were killed and middle intestine was taken. Pathology was examined by HE staining. Musashi-1 (msi-1) expression was detected by immunohistochemical technique. The percentage of Rho low staining cells was detected by flow cytometry.</p><p><b>RESULTS</b>After treatment with 5-FU, the intestinal mucosa was damaged. The Rho low staining cells were increasing, and at day 1 after treatment, the percentage of Rho low staining cells reached the highest level (P<0.01). The number of cells expressing msi-1 did not change significantly (P>0.05), but the percentage of positive msi-1 cells increased significantly (P<0.01). There was positive correlation between the percentage of Rhodamine 123 low staining cells and positive msi-1 cells in each group (r=0.867, P<0.01).</p><p><b>CONCLUSIONS</b>The Rho low staining cells may contain rich intestinal epithelial stem cells. The intestinal epithelial stem cells expressing msi-1 can regenerate the damage of intestinal mucosa induced by 5-FU.</p>

L-arginine reduces intestinal epithelial cell apoptosis in rats with severe abdominal infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of L-arginine (L-Arg) on intestinal mucosal cell apoptosis in rats with severe abdominal infection.</p><p><b>METHODS</b>Eighteen Wistar rats were randomized into 3 groups, namely the CLP group (n=6) in which the rats were subjected to cecal ligation plus puncture (CLP) to induce severe abdominal infection, L-Arg group (n=6) where the rats received 300 mg/kg peritoneal L-Arg injection following CLP establishment, and the control group (n=6) where the rats underwent ventrotomy only. Intestinal epithelial apoptotic cells were quantified in each group using TUNEL assay 24 h after the operation.</p><p><b>RESULTS</b>Compared with the control group, the rats in CLP and L-Arg groups showed significantly increased number of apoptotic cells in the intestinal epithelium 24 h after the operation (P<0.001). The apoptotic index (AI) in the L-Arg group (18.1-/+2.2) was significantly lower than that in CLP group (20.8-/+2.3, P=0.038).</p><p><b>CONCLUSION</b>Severe abdominal infection results in increased apoptosis of the intestinal epithelial cells in rats, and L-Arg treatment may reduce the cell apoptosis.</p>

Expression of proliferating cell nuclear antigen in severely damaged small intestinal mucosa due to high-dose 5-FU exposure / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the expression of proliferating cell nuclear antigen (PCNA) in severely damaged intestinal mucosa due to high-dose 5-FU exposure.</p><p><b>METHODS</b>Thirty-two adult C57BL/6J mice were subjected to daily intraperitoneal high-dose 5-FU injection at 150 mg/kg for 5 consecutive days, and on days 1, 3, and 5, the mice were sacrificed to obtain the small intestinal tissue for HE straining and immunohistochemistry for detecting PCNA expression. Another 8 mice with intraperitoneal PBS injection served as the control group.</p><p><b>RESULTS</b>High-dose 5-FU exposure of the mice resulted in severe intestinal mucous damage, with complete destruction of the villi and crypts and significantly increased cells positive for PCNA expression (P<0.01).</p><p><b>CONCLUSION</b>High-dose 5-FU treatment can significantly increase the PCNA index, and the cells expressing PCNA can be closely associated with regeneration of the severely damaged mucosa due to the exposure.</p>

Intestinal mucosal pathology in rats with severe abdominal infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the pathological changes of the intestinal mucosa in rats with severe abdominal infection.</p><p><b>METHOD</b>A total of 60 SD rats were divided randomly into control group and experimental group (n=30), and in the latter group, the rats underwent cecal ligation and puncture (CLP) while those in the former had only laparotomy. The jejunum and ileum were sampled on postoperative days 1, 2 and 4 for optical and electron microscopic observations. The positivity rate of blood bacterial culture and plasma level of endotoxin were determined in the rats.</p><p><b>RESULTS</b>No abnormal changes were observed with either optical and electron microscope in the small intestinal mucous membrane of rats in the control group, but in rats of the experimental group, microscopic examination revealed interstitial edema, vascular engorgement and neutrophil infiltration in the small intestine mucous membrane and the submucosa, and electron microscopy demonstrated loose and disorderly arrangement of the microvilli of the intestinal epithelium. Plasma endotoxin level in rats in the experimental group was 5- to 12-fold higher than that in the control group. The positivity rates of blood bacterial culture were 20%, 30% and 10% on postoperative days 1, 2 and 4 respectively in the experimental group, but were all zero in the control group.</p><p><b>CONCLUSION</b>Pathologic lesions in the intestinal mucosa occur during the early stage of severe abdominal infection in rats as the result of bacteria and endotoxin translocation.</p>

Beta-catenin expression in intestinal mucosa of rats with severe abdominal infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of beta-catenin in the intestinal mucosa of rats with severe abdominal infection.</p><p><b>METHODS</b>Forty healthy adult Wistar rats were randomly divided into a control group (n=10, with celiotomy only) and 3 abdominal infection groups (n=10) sacrificed at 12, 24, 48 h after cecal ligation plus puncture for inducing severe abdominal infection, respectively. Immunohistochemistry and RT-PCR were performed to detect beta-catenin expression in the crypt of the small intestine during severe abdominal infection and in normal conditions.</p><p><b>RESULTS</b>Rats with severe abdominal infection showed stronger beta-catenin expression in the crypt of the small intestine than normal rats, and the transcription level of beta-catenin was associated with the stages of severe abdominal infection. RT-PCR showed that beta-catenin mRNA increased rapidly 12 h after the infection (0.74-/+0.10 vs 0.52-/+0.06, P<0.01), reaching the peak level at 24 h (0.90-/+0.09, P<0.01), followed then by gradual decrease but remained still obviously higher than the control level at 24 h (0.80-/+0.09, P<0.01).</p><p><b>CONCLUSIONS</b>Severe abdominal infection may induce beta-catenin expression which might be related with the proliferation and differentiation of intestinal stem cells in such condition and play an important role in intestinal mucosa damage and repair.</p>

The expression of musashi-1 in small intestinal mucosa severely damaged by high dose 5-FU / 中国普通外科杂志

Objective To investigate the expression of musashi-1(msi-1)and its significances in small intestinal mucous severely damaged by high close 5-FU.Methods Total 40 adult C57BL/6J mice were divided into control group(n= 8,group D)and experimental group(n=32).Mice in control group received intraperitoneal injection of PBS as control,and mice in experimental group were intraperitoneally injected high dose 5-FU(150 mg per kg of body weigh for five days).After treatment 1 day(group A),3 days(group B)and 5 days( group C),the dying mice were killed,HE straining and immunohistochemical technique were carried out for detecting the expression of putative marker of intestinal epithelial stem cells——musashi-1(msi-1)in the samples of the meddle intestine,and the percentage of the msi-1 positive cells from the intestinal mucosal cells of the mice in group A was detected by flow cytometry.Results After the treatment of high dose 5-FU,the intestinal mucous was damaged severely;the number of msi-1 positive cells increased markedly;The intestinal mucosal cells can be divided into two groups by flow cytometry,and in the group in which the value of FSC was higher,the percentage of msi-1 positive cells increased to 67.75 %.Conclusions After the treatment of high dose of 5-FU,the percentage of intestinal stem cells increased significantly;this model may be useful for further isolation and enrichment of intestinal epithelial stem cells.