LKB1 regulates epithelial-mesenchymal transition in Peutz-Jeghers hamartoma and intestinal epithelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the molecular mechanism by which LKB1 regulates epithelial-mesenchymal transition (EMT) in Peutz-Jeghers hamartoma and intestinal epithelial cells.</p><p><b>METHODS</b>Immunohistochemistry was used to detect gene expression of LKB1, E-cadherin, and vimentin in 20 hamartoma tissues and 10 normal intestinal tissues, and collagen fiber deposition was analyzed using Masson trichrome staining. Normal intestinal epithelial NCM460 cells were transfected with LKB1 shRNA plasmid or negative control via lentiviral vectors, and the role of LKB1 in cell polarization and migration were determined using CCK8 and Transwell assays. Western blotting, quantitative real-time PCR (qPCR) and immunofluorescence were used to assess the alterations of EMT markers in the cells with LKB1 knockdown.</p><p><b>RESULTS</b>Compared with normal intestinal tissues, hamartoma polyps showed significantly decreased LKB1 and E-cadherin expressions and increased vimentin expression with increased collagen fiber deposition. The cells with LKB1 knockdown exhibited enhanced cell proliferation and migration activities (P<0.01). Western blot analysis, qPCR and immunofluorescence all detected decreased E-cadherin and increased N-cadherin, vimentin, Snail, and Slug expressions in the cells with LKB1 knockdown.</p><p><b>CONCLUSION</b>s LKB1 deficiency triggers EMT in intestinal epithelial cells and Peutz-Jeghers hamartoma, suggesting that EMT can serve as the therapeutic target for treatment of Peutz-Jeghers syndrome.</p>

Reply: The Characteristics about Our Study in Irritable Bowel Syndrome

No abstract available.

Risk factors of pain during colonoscopic examination / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the risk factorsthat predict pain during colonoscopy for decision of sedation or analgesia before the examination.</p><p><b>METHODS</b>A total of 283 consecutive patients undergoing colonoscopicexamination at Nanfang Hospital between July, 2016 and September, 2016were retrospectively analyzed. The clinical data and visual analogue scale after the examination were analyzed to identify the risk factors for pain during colonoscopy using univariate analysis and multivariate logistic regression. A risk stratification model for predicting pain in colonoscopy was established.</p><p><b>RESULTS</b>The completion rate of the procedure was significantly lower in patients with a visual analogue scale ≥5 (P<0.000). Univariate analysis showed that female patients, previous abdominal surgery, no previous experience with colonoscopy, complaint of abdominal pain before colonoscopy, insufficient experience of the endoscopists, patient's anticipation of high painlevelbefore examination, and a low body mass index (BMI) were all associated with the experience of pain in colonoscopy (P<0.05). Multivariate logistic regressionanalysis identified BMI index (X), level of experience of the endoscopist (A, A, A) and the patient's anticipation of painlevel (X) as the risk factors of pain in colonoscopy(P<0.05), and the establishedmodel with the 3 variables was: P=e/(1+e),Y=0.049-0.124×X-0.97×X+1.713×A+0.781×A+0.147×A, which showed a sensitivity of 70.3% and a specificity of 67.5%for predicting pain in colonoscopy.</p><p><b>CONCLUSION</b>The patient's anticipation of a high pain level in colonoscopy, insufficient experience of the endoscopist, and a low BMI are the independent risk factors for pain in colonoscopy, and evaluation of these factors can help in the decision-making concerning the use of sedation or analgesia before colonoscopy.</p>

Value of urgent colonoscopy in diagnosis of severe acute lower gastrointestinal bleeding in patients with different bowel cleanliness / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the value of urgent colonoscopy in the diagnosis of severe acute lower gastrointestinal bleeding and the optimal bowel preparation before examination.</p><p><b>METHODS</b>The clinical data were collected from 188 patients undergoing wither urgent or elective colonoscopy for severe acute lower gastrointestinal bleeding in Nanfang Hospital. Univariate analysis was used to assess the effect of the timing of colonoscopy on the diagnostic rate of hemorrhage, and a multivariate model which stratified bowel cleanliness was used to analyze the impact of bowel cleanliness on the diagnostic rate of urgent colonoscopy.</p><p><b>RESULTS</b>Of the 188 patients, 118 underwent urgent colonoscopy and 70 underwent elective colonoscopy examinations. The diagnostic rates were comparable between the two groups (44.1% vs 41.4%, P=0.724), but urgent colonoscopy resulted in a significantly higher diagnostic rate for identifying the bleeding source (32.2% vs 18.6%, P=0.041). The proportion of the patients taking oral laxatives was significantly lower in urgent colonoscopy group (P<0.001). Oral laxatives versus enema resulted in good, moderate, and poor bowel cleanliness in 63.6% vs 13.5%, 28.6% vs 24.3%, and 7.8% vs 62.2% of the patients (P<0.001). Univariate analysis indicated that good bowel cleanliness was associated with a significantly higher diagnostic rate of colonoscopy than poor bowel cleanliness (P=0.012). Multivariate analysis showed that with good bowel cleanliness, urgent colonoscopy yielded a significantly higher diagnostic rate than elective colonoscopy (P=0.030); subgroup analyses suggested that good bowel cleanliness improved the diagnostic rate of urgent colonoscopy as compared with poor bowel cleanliness (P=0.015).</p><p><b>CONCLUSION</b>In patients with good bowel cleanliness, urgent colonoscopy yields a higher diagnostic rate than elective colonoscopy for severe acute lower gastrointestinal bleeding. Poor bowel cleanliness resulting from bowel preparation by enema significantly lowers the diagnostic performance of urgent colonoscopy. Oral laxatives are recommended over enemas for bowel preparation before urgent colonoscopy when the patients have stable hemodynamics.</p>

Palmitic acid induces hepatocellular oxidative stress and activation of inflammasomes / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of palmitic acid (PA) on oxidative stress and activation of inflammasomes in hepatocytes.</p><p><b>METHODS</b>To test the dose-dependent effect of PA on normal murine hepatocytes AML12, the cells were treated with 0, 0.15, 0.25 and 0.4 mmol/L of palmitic acid (PA). The cells were also divided into blank control group, 0.25 mmol/L PA group and 0.25 mmol/L PA+N-acetylcysteine (NAC) group to examine the effect of reactive oxygen species (ROS) on the activation of inflammasomes. After 24 h of treatment, lipid accumulation, total ROS, mitochondrial ROS, expression and localization of NOX4, and expressions of inflammasomes and IL-1β were detected in the hepatocytes.</p><p><b>RESULTS</b>Compared with the control cells, PA treatment of the cells significantly increased cytoplasmic lipid accumulation, concentrations of total ROS (12 463.09±2.72 vs 6691.23±2.45, P=0.00) and mitochondrial ROS (64.98±0.94 vs 45.04±0.92, P=0.00), and the expressions of NOX4, NLRP3, ASC, caspase-1, and IL-1β (1603.52±1.32 vs 2629.33±2.57, P=0.00). The mitochondria and NOX4 were found to be co-localized in the cytoplasm. NAC obviously reduced cellular ROS level stimulated by PA (7782.15±2.87 vs 5445.6±1.17, P=0.00) and suppressed the expressions of NLRP3, ASC and caspase-1.</p><p><b>CONCLUSION</b>PA treatment can stimulate lipid accumulation in hepatocytes and induce oxidative stress through NOX4 and mitochondria pathway to activate inflammasomes and stimulate the secretion of IL-1β.</p>

Association between Diet and Lifestyle Habits and Irritable Bowel Syndrome: A Case-Control Study

BACKGROUND/AIMS: Recent papers have highlighted the role of diet and lifestyle habits in irritable bowel syndrome (IBS), but very few population-based studies have evaluated this association in developing countries. The aim of this study was to evaluate the association between diet and lifestyle habits and IBS. METHODS: A food frequency and lifestyle habits questionnaire was used to record the diet and lifestyle habits of 78 IBS subjects and 79 healthy subjects. Cross-tabulation analysis and logistic regression were used to reveal any association among lifestyle habits, eating habits, food consumption frequency, and other associated conditions. RESULTS: The results from logistic regression analysis indicated that IBS was associated with irregular eating (odds ratio [OR], 3.257), physical inactivity (OR, 3.588), and good quality sleep (OR, 0.132). IBS subjects ate fruit (OR, 3.082) vegetables (OR, 3.778), and legumes (OR, 2.111) and drank tea (OR, 2.221) significantly more frequently than the control subjects. After adjusting for age and sex, irregular eating (OR, 3.963), physical inactivity (OR, 6.297), eating vegetables (OR, 7.904), legumes (OR, 2.674), drinking tea (OR, 3.421) and good quality sleep (OR, 0.054) were independent predictors of IBS. CONCLUSIONS: This study reveals a possible association between diet and lifestyle habits and IBS.

Observation of special staining of human colorectal carcinoma cell lines cultured on nitrocellulose membrane / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the special staining of cells cultured on nitrocellulose (NC) membrane and evaluate the application of the novel method for cell culture and pathological staining.</p><p><b>METHODS</b>Human colorectal carcinoma SW1116 cell line and SW480 cell line were cultured using nitrocellulose membrane as the culture matrix, with the same cells cultured on slides serving as the control.</p><p><b>RESULTS</b>The cells cultured on NC membrane appeared transparent with sharp edge and purple background by macroscopic observation, showing on obvious difference in terms of cell morphology and number from the cells cultured on glass slides. Irregular polygonal SW1116 cells and SW480 cells were found on the NC membrane, on which the cells grew in colony and showed blue nucleus and red cytoplasm.</p><p><b>CONCLUSIONS</b>NC membrane produces no cytotoxicity and can be used for cell culture without affecting the normal cell morphology and number during cell culture, thus providing a new means for cell culture and pathological staining.</p>

Intrasplenic heterotransplantation of in vitro cultured human fetal hepatic stem cells for treatment of acute liver injury in mice with severe combined immunodeficiency / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the in vivo colonization, migration, and differentiation of in vitro cultured human fetal hepatic stem cells (HSCs) following intrasplenic transplantation for treatment of acute liver injury in mice with severe combined immunodeficiency (SCID).</p><p><b>METHODS</b>Human fetal HSCs were isolated from the normal fetal liver (16-24 weeks) and purified, and the morphology of HSCs was observed under optical and transmission electron microscopes. The expressions of stem cell markers were examined in these HSCs by means of immunocytochemistry and flow cytometry. The passaged human fetal HSC suspension (0.2 ml) were injected into the spleen of SCID mice with acute liver injury induced by two-third partial hepatectomy, and 15, 30, 60, and 90 days after cell transplantation, immunohistochemistry was performed to examine the location and expressions of human hepatocytes, alpha1-AT and AFP antigen in the spleen and liver of the recipient SCID mice. PAS staining was used to examine the expression of glycogen and RT-PCR employed for detection of the expressions of AFP and albumin mRNA in the spleen of the mice on the scheduled time points.</p><p><b>RESULTS</b>Under optical microscope and transmission electron microscope, most of the HSCs were small, about 1/6 to 1/3 of the size of the hepatocyte, with relatively large nucleus-cytoplasm ratio and only small quantities of endocytoplasmic reticulum, chondriosome, and ribosome. Immunohistochemistry and flow cytometry identified positive expressions of AFP, Thy-1, C-kit, CD34 and CK19 in the HSCs, and after cell transplantation, positive expressions of human hepatocyte, alpha1-AT, and AFP antigen occurred in the liver and spleen of the recipient SCID mice. PAS staining confirmed the presence of glycogenosome in the spleen of the mice following cell transplantation. RT-PCR on days 30, 60, and 90 showed positive expressions of human AFP and albumin mRNA in the spleen of the mice.</p><p><b>CONCLUSION</b>Human fetal HSCs can survive and settle in the spleen and liver, and migrate to the damaged liver of the recipient mice after intrasplenic transplantation, with the capacity of proliferation and differentiation into hepatocytes in the recipient target organs.</p>