Paneth Cell Alertness to Pathogens Maintained by Vitamin D Receptors.

BACKGROUND AND AIMS: Vitamin D exerts a regulatory role over mucosal immunity via the vitamin D receptor (VDR). Although Paneth cells and their products are known to regulate the commensal and pathogenic microbiota, the role that VDRs in Paneth cells play in these responses is unknown. METHODS: We identified the decreased intestinal VDR significantly correlated with reduction of an inflammatory bowel disease risk gene ATG16L1 and Paneth cell lysozymes in patients with Crohn's disease. We generated Paneth cell-specific VDR knockout (VDRΔPC) mice to investigate the molecular mechanisms. RESULTS: Lysozymes in the Paneth cells were significantly decreased in the VDRΔPC mice. Isolated VDRΔPC Paneth cells exhibited weakened inhibition of pathogenic bacterial growth and displayed reduced autophagic responses. VDRΔPC mice had significantly higher inflammation after Salmonella infections. VDRΔPC mice also showed high susceptibility to small intestinal injury induced by indomethacin, a nonsteroidal anti-inflammatory drug. Co-housing of VDRΔPC and VDRlox mice made the VDRΔPC less vulnerable to dextran sulfate sodium colitis, suggesting the transmission of protective bacterial from the VDRlox mice. Thus, a lack of VDR in Paneth cells leads to impaired antibacterial activities and consequently increased inflammatory responses. Genetically and environmentally regulated VDRs in the Paneth cells may set the threshold for the development of chronic inflammation, as observed in inflammatory bowel diseases. CONCLUSIONS: We provide new insights into the tissue-specific functions of VDRs in maintaining Paneth cell alertness to pathogens in intestinal disorders. Targeting the VDR affects multiple downstream events within Paneth cells that inhibit intestinal inflammation and establish host defense against enteropathogens.

Imbalance of autophagy and apoptosis in intestinal epithelium lacking the vitamin D receptor.

Apoptosis and autophagy are dynamic processes that determine the fate of cells. Vitamin D receptor (VDR) deficiency in the intestine leads to abnormal Paneth cells and impaired autophagy function. Here, we will elucidate the mechanisms of the intestinal epithelial VDR regulation of autophagy and apoptosis. We used in vivo VDRlox and VDR∆IEC mice and ex vivo organoids generated from small intestine and colon tissues. We found that VDR deficiency induced more apoptotic cells and significantly increased cell death in the small intestine and colon of VDR∆IEC mice. The proapoptotic protein B-cell lymphoma 2 (BCL-2) associated X protein (Bax) was enhanced, whereas autophagy related 16 like 1 (ATG16L1) and Beclin-1 were decreased in the intestines of VDRΔIEC mice. Apoptosis induced by Bax reduced autophagy by decreasing Beclin-1. Physical interactions between Beclin-1 and Bcl-2 were increased in the VDR-deficient epithelia from mice. The growth of VDR∆IEC organoids was significantly slower with fewer Paneth cells than that of VDR+/+ organoids. The expression levels of Beclin-1 and lysozyme were decreased in VDR∆IEC organoids. Bacterial endotoxin levels were high in the serum from VDR∆IEC mice and made mice susceptible to colitis. In the organoids and colitis IL-10-/- mice, vitamin D3 treatment increased VDR and ATG16L1 protein expression levels, which activated autophagic responses. In summary, intestinal epithelial VDR regulates autophagy and apoptosis through ATG16L1 and Beclin-1. Our studies provide fundamental insights into the tissue-specific function of VDR in modulating the balance between autophagy and apoptosis.-Lu, R., Zhang, Y.-G., Xia, Y., Sun, J. Imbalance of autophagy and apoptosis in intestinal epithelium lacking the vitamin D receptor.

Salmonella enteritidis Effector AvrA Stabilizes Intestinal Tight Junctions via the JNK Pathway.

Salmonella pathogenesis studies to date have focused on Salmonella typhimurium, and the pathogenesis of a second major serotype, Salmonella enteritidis, is poorly understood. Salmonella spp. possess effector proteins that display biochemical activities and modulate host functions. Here, we generated a deletion mutant of the effector AvrA, S.E-AvrA-, and a plasmid-mediated complementary strain, S.E-AvrA-/pAvrA+ (S.E-AvrA+), in S. Enteritidis. Using in vitro and in vivo infection models, we showed that AvrA stabilizes epithelial tight junction (TJ) proteins, such as ZO-1, in human intestinal epithelial cells. Transepithelial electrical resistance was significantly higher in cells infected with S.E-AvrA+ than in cells infected with S.E-AvrA- Inhibition of the JNK pathway suppresses the disassembly of TJ proteins; we found that enteritidis AvrA inhibited JNK activity in cells infected with wild type or S.E-AvrA+ strains. Therefore, Enteritidis AvrA-induced ZO-1 stability is achieved via suppression of the JNK pathway. Furthermore, the S.E-AvrA- strain led to enhanced bacterial invasion, both in vitro and in vivo Taken together, our data reveal a novel role for AvrA in S. Enteritidis: Enteritidis AvrA stabilizes intestinal TJs and attenuates bacterial invasion. The manipulation of JNK activity and TJs in microbial-epithelial interactions may be a novel therapeutic approach for the treatment of infectious diseases.

Intestinal epithelial vitamin D receptor deletion leads to defective autophagy in colitis.

OBJECTIVE: Vitamin D and the vitamin D receptor (VDR) appear to be important immunological regulators of inflammatory bowel diseases (IBD). Defective autophagy has also been implicated in IBD, where interestingly, polymorphisms of genes such as ATG16L1 have been associated with increased risk. Although vitamin D, the microbiome and autophagy are all involved in pathogenesis of IBD, it remains unclear whether these processes are related or function independently. DESIGN: We investigated the effects and mechanisms of intestinal epithelial VDR in healthy and inflamed states using cell culture models, a conditional VDR knockout mouse model (VDR(ΔIEC)), colitis models and human samples. RESULTS: Absence of intestinal epithelial VDR affects microbial assemblage and increases susceptibility to dextran sulfate sodium-induced colitis. Intestinal epithelial VDR downregulates expressions of ATG16L1 and lysozyme, and impairs antimicrobial function of Paneth cells. Gain and loss-of-function assays showed that VDR levels regulate ATG16L1 and lysozyme at the transcriptional and translational levels. Moreover, low levels of intestinal epithelial VDR correlated with reduced ATG16L1 and representation by intestinal Bacteroides in patients with IBD. Administration of the butyrate (a fermentation product of gut microbes) increases intestinal VDR expression and suppresses inflammation in a colitis model. CONCLUSIONS: Our study demonstrates fundamental relationship between VDR, autophagy and gut microbial assemblage that is essential for maintaining intestinal homeostasis, but also in contributing to the pathophysiology of IBD. These insights can be leveraged to define therapeutic targets for restoring VDR expression and function.

Vitamin D receptor pathway is required for probiotic protection in colitis.

Low expression of vitamin D receptor (VDR) and dysfunction of vitamin D/VDR signaling are reported in patients with inflammatory bowel disease (IBD); therefore, restoration of VDR function to control inflammation in IBD is desirable. Probiotics have been used in the treatment of IBD. However, the role of probiotics in the modulation of VDR signaling to effectively reduce inflammation is unknown. We identified a novel role of probiotics in activating VDR activity, thus inhibiting inflammation, using cell models and VDR knockout mice. We found that the probiotics Lactobacillus rhamnosus strain GG (LGG) and Lactobacillus plantarum (LP) increased VDR protein expression in both mouse and human intestinal epithelial cells. Using the VDR luciferase reporter vector, we detected increased transcriptional activity of VDR after probiotic treatment. Probiotics increased the expression of the VDR target genes, such as antimicrobial peptide cathelicidin, at the transcriptional level. Furthermore, the role of probiotics in regulating VDR signaling was tested in vivo using a Salmonella-colitis model in VDR knockout mice. Probiotic treatment conferred physiological and histologic protection from Salmonella-induced colitis in VDR(+/+) mice, whereas probiotics had no effects in the VDR(-/-) mice. Probiotic treatment also enhanced numbers of Paneth cells, which secrete AMPs for host defense. These data indicate that the VDR pathway is required for probiotic protection in colitis. Understanding how probiotics enhance VDR signaling and inhibit inflammation will allow probiotics to be used effectively, resulting in innovative approaches to the prevention and treatment of chronic inflammation.

Conditional Vitamin D Receptor Deletion Induces Fungal and Archaeal Dysbiosis and Altered Metabolites.

A vitamin D receptor (VDR) deficiency leads to the dysbiosis of intestinal bacteria and is associated with various diseases, including cancer, infections, and inflammatory bowel disease. However, the impact of a VDR deficiency on fungi and archaea is unknown. We conditionally deleted the VDR in Paneth cells (VDRΔPC), intestinal epithelial cells (VDRΔIEC), or myeloid cells (VDRΔLyz) in mice and collected feces for shotgun metagenomic sequencing and untargeted metabolomics. We found that fungi were significantly altered in each knockout (KO) group compared to the VDRLoxp control. The VDRΔLyz mice had the most altered fungi species (three depleted and seven enriched), followed by the VDRΔPC mice (six depleted and two enriched), and the VDRΔIEC mice (one depleted and one enriched). The methanogen Methanofollis liminatans was enriched in the VDRΔPC and VDRΔLyz mice and two further archaeal species (Thermococcus piezophilus and Sulfolobus acidocaldarius) were enriched in the VDRΔLyz mice compared to the Loxp group. Significant correlations existed among altered fungi, archaea, bacteria, and viruses in the KO mice. Functional metagenomics showed changes in several biologic functions, including decreased sulfate reduction and increased biosynthesis of cobalamin (vitamin B12) in VDRΔLyz mice relative to VDRLoxp mice. Fecal metabolites were analyzed to examine the involvement of sulfate reduction and other pathways. In conclusion, a VDR deficiency caused the formation of altered fungi and archaea in a tissue- and sex-dependent manner. These results provide a foundation about the impact of a host factor (e.g., VDR deficiency) on fungi and archaea. It opens the door for further studies to determine how mycobiome and cross-kingdom interactions in the microbiome community and metabolites contribute to the risk of certain diseases.

The first complete genomic characterization of an Amur virus isolate from China.

Amur virus (AMRV) is a member of the genus Hantavirus in the family Bunyaviridae. In this study, we determined for the first time the complete genome sequence of the AMRV H8205 strain, which was isolated from a patient with hemorrhagic fever with renal syndrome (HFRS) in China. The complete nucleotide sequence of the S segment of AMRV H8205 is 1699 nt long, with a 5' noncoding region (5'NC) of 36 nt, followed by a coding sequence of 1290 nt and a 3'NC of 373 nt. The complete sequence of the M segment is 3615 nt long, with a 5'NC of 40 nt, followed by a coding sequence of 3408 nt and a 3'NC of 167 nt. The complete sequence of the L segment is 6536 nt long, with a 5'NC of 37 nt, followed by a coding sequence of 6453 nt and a 3'NC of 40 nt. The major open reading frame (ORF) of each of the three segments (S, nt 37-1326; M, nt 41-3445; L, nt 38-6490) has a coding capacity of 430 aa, 1135 aa, 2151 aa, respectively. Phylogenetic analysis of the nucleotide sequences using the NJ method indicated that H8205 virus, together with the Amur strains isolated from Far-Eastern Russia and Korea, forms a well-supported lineage. Our results will provide insights into the genetic diversity of hantaviruses (HNTV).

[Effects of anti-osteopontin antibody on expression of MMP-2 and TGF-beta1 in hepatic alveolar hydatid tissue of gerbil].

OBJECTIVE: To observe the effect of anti-osteopontin antibody on the level of matrix metalloproteinase (MMP-2) and TGF-beta1 in gerbils infected with Echinococcus multilocularis. METHODS: One hundred and eighty gerbils were infected with Echinococcus protoscoleces (approximately 400 for each gerbil) by abdominal opening inoculation in liver. The gerbils were randomly divided into three groups: anti-osteopontin antibody experiment group (group A), rabbit serum injection group (group B), and model group (group C). Gerbils in groups A and B were injected with antiosteopontin antibodies and rabbit serum (0.15 mi/gerbil) via tail vein, respectively. Ten gerbils from each group were sacrificed at 20, 60, 100, 140, 180, and 220 days post-infection, respectively. The liver tissue with hydatid cysts were collected and the expression of MMP-2 and TGF-beta1 was observed by immunohistochemistry staining (SP method). RESULTS: E. multilocularis hydatid tissue spreader over the liver and abdominal cavity. There was no significant difference in the number of MMP-2-positive gerbils among the three groups (P > 0.05). At 100, 140, and 180 days post-infection, the number of TGF-beta1-positive gerbils in group A (3, 2, and 2) was considerably less than that of group B (8, 8, and 9) and group C (8, 9, and 9) (P < 0.05). CONCLUSION: Anti-osteopontin antibody can reduce the expression of TGF-beta1 in hepatic alveolar hydatid tissue of gerbils at certain time, but have no effect on MMP2.

Intestinal vitamin D receptor protects against extraintestinal breast cancer tumorigenesis.

The microbiota plays critical roles in regulating the function and health of the intestine and extraintestinal organs. A fundamental question is whether an intestinal-microbiome-breast axis exists during the development of breast cancer. If so, what are the roles of host factors? Vitamin D receptor (VDR) involves host factors and the human microbiome. Vdr gene variation shapes the human microbiome, and VDR deficiency leads to dysbiosis. We hypothesized that intestinal VDR protects hosts against tumorigenesis in the breast. We examined a 7,12-dimethylbenzanthracene (DMBA)-induced breast cancer model in intestinal epithelial VDR knockout (VDRΔIEC) mice with dysbiosis. We reported that VDRΔIEC mice with dysbiosis are more susceptible to breast cancer induced by DMBA. Intestinal and breast microbiota analysis showed that VDR deficiency leads to a bacterial profile shift from normal to susceptible to carcinogenesis. We found enhanced bacterial staining within breast tumors. At the molecular and cellular levels, we identified the mechanisms by which intestinal epithelial VDR deficiency led to increased gut permeability, disrupted tight junctions, microbial translocation, and enhanced inflammation, thus increasing tumor size and number in the breast. Furthermore, treatment with the beneficial bacterial metabolite butyrate or the probiotic Lactobacillus plantarum reduced breast tumors, enhanced tight junctions, inhibited inflammation, increased butyryl-CoA transferase, and decreased levels of breast Streptococcus bacteria in VDRΔIEC mice. The gut microbiome contributes to the pathogenesis of diseases not only in the intestine but also in the breast. Our study provides insights into the mechanism by which intestinal VDR dysfunction and gut dysbiosis lead to a high risk of extraintestinal tumorigenesis. Gut-tumor-microbiome interactions represent a new target in the prevention and treatment of breast cancer.

The Incidence of Acute Pancreatitis After Device Assisted Enteroscopy: a Systematic Review and Meta-analysis.

Background: The diagnosis of small bowel diseases is challenging and device assisted enteroscopy (DAE) is a technique for visualizing the entire small bowel. DAE is considered as a safe procedure and the reported rate of adverse events associated with DAE in the literature is low. Objective: The present study tried to investigate the actual incidence of AP after DAE with a systematic review and meta-analysis of available relevant studies. Methods: Studies were searched through the PubMed, EMBASE, and Cochrane library databases. The following data were extracted from all eligible studies: author, country, publication year, publication type, study design, type of DAE used, route of DAE, number of patients with AP after DAE, and number of patients with hyperamylasemia after DAE.A random-effects model with RStudio version 4.2.0 was performed in all analyses. Heterogeneity was assessed using the I2 test. The risk of bias was assessed by the Newcastle-Ottawa Scale criteria and the publication bias was assessed by the Egger test. Results: Twenty three studies involving a total of 11145 patients were included in the analysis. The overall, pooled AP rate after DAE was 1% (95% CI:0-1%). There was significant heterogeneity among the studies (I2 = 65%; P < 0.01).The pooled AP rate was 1% (95% CI:0-2 %)in peroral route group. The pooled proportion of patients having hyperamylasemia after DAE was 29% (95% CI: 16-46%).Among the patients who had hyperamylasemia AP were identified in 2% (95% CI: 0-6%) of patients. Conclusion: The incidence of AP after DAE is about 1%. Hyperamylasemia is a common change in the patients undergoing DAE and only 2% of the patients with hyperamylasemia present with AP.

The Impact of Maternal Probiotics on Intestinal Vitamin D Receptor Expression in Early Life.

Vitamin D signaling via the Vitamin D Receptor (VDR) has been shown to protect against intestinal inflammation. Previous studies have also reported the mutual interactions of intestinal VDR and the microbiome, indicating a potential role of probiotics in modulating VDR expression. In preterm infants, although probiotics have been shown to reduce the incidence of necrotizing enterocolitis (NEC), they are not currently recommended by the FDA due to potential risks in this population. No previous studies have delved into the effect of maternally administered probiotics on intestinal VDR expression in early life. Using an infancy mouse model, we found that young mice exposed to maternally administered probiotics (SPF/LB) maintained higher colonic VDR expression than our unexposed mice (SPF) in the face of a systemic inflammatory stimulus. These findings indicate a potential role for microbiome-modulating therapies in preventing diseases such as NEC through the enhancement of VDR signaling.

Effects of postoperative use of proton pump inhibitors on gastrointestinal bleeding after endoscopic variceal treatment during hospitalization.

BACKGROUND: Endoscopic variceal treatment (EVT) is recommended as the mainstay choice for the management of high-risk gastroesophageal varices and acute variceal bleeding in liver cirrhosis. Proton pump inhibitors (PPIs) are widely used for various gastric acid-related diseases. However, the effects of PPIs on the development of post-EVT complications, especially gastrointestinal bleeding (GIB), remain controversial. AIM: To evaluate the effects of postoperative use of PPIs on post-EVT complications in patients with liver cirrhosis during hospitalization. METHODS: Patients with a diagnosis of liver cirrhosis who were admitted to the Department of Gastroenterology of the General Hospital of Northern Theater Command, treated by an attending physician between January 2016 and June 2020 and underwent EVT during their hospitalization were included. Logistic regression analyses were performed to explore the effects of postoperative use of PPIs on the development of post-EVT complications during hospitalization. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: A total of 143 patients were included. The incidence of post-EVT GIB and other post-EVT complications was 4.90% and 46.85%, respectively. In the overall analyses, postoperative use of PPIs did not significantly reduce the risk of post-EVT GIB (OR = 0.525, 95%CI = 0.113-2.438, P = 0.411) or other post-EVT complications (OR = 0.804, 95%CI = 0.413-1.565, P = 0.522). In the subgroup analyses according to the enrollment period, type and route of PPIs after the index EVT, use of PPIs before the index EVT, use of vasoactive drugs after the index EVT, indication of EVT (prophylactic and therapeutic), and presence of portal venous system thrombosis, ascites, and hepatocellular carcinoma, the effects of postoperative use of PPIs on the risk of post-EVT GIB or other post-EVT complications remain not statistically significant. CONCLUSION: Routine use of PPIs after EVT should not be recommended in patients with liver cirrhosis for the prevention of post-EVT complications during hospitalization.

Thrifty effect of subanesthetic-dose S-ketamine on postoperative opioids and its safety and analgesic effectiveness: A prospective, triple-blind, randomized controlled, polycentric clinical trial.

Aim: To investigate the thrifty effects of subanesthetic-dose S-ketamine on postoperative opioids and its safety and analgesic efficacy. Methods: Four-hundred and twenty patients were divided into the control group (CON group), the S-ketamine 0.2 mg/kg group (ES0.2 group), and the S-ketamine 0.3 mg/kg group (ES0.3 group) randomly. Major indicators include the Visual Analogue Scale (VAS), the times of compression with analgesic pumps after surgery, and analgesic drug consumption from anesthesia induction to 48 h after surgery. Minor records include vital signs, the use of vasoactive drugs, the Ramsay scores, the occurrence of adverse events including nervous system reaction, and the patient's satisfaction with anesthesia. Results: Compared with the CON group, VAS scores decreased in the ES0.2 and ES0.3 groups (p < 0.05). At 10 min after extubation, the VAS scores of the ES0.3 group were lower than that of the ES0.2 group (p < 0.05). The total number of compression with analgesic pumps of the ES0.3 group was lower than that of the CON group (p < 0.05). The opioid consumption after surgery of the ES0.3 group was lower than those of the CON group and the ES0.2 group (p < 0.05). The ES0.3 group's heart rate (HR) was faster but the use of vasoactive, drug consumption was less than the other two groups (p < 0.05). There were no significant differences in the incidence of postoperative adverse events and anesthetic satisfaction among the three groups. Conclusion: Subanesthetic-dose S-ketamine at 0.2-0.3 mg/kg especially the 0.3 mg/kg in general anesthesia induction can safely and effectively reduce postoperative pain and save postoperative opioid consumption.

Consistent activation of the ß-catenin pathway by Salmonella type-three secretion effector protein AvrA in chronically infected intestine.

Salmonella infection is a common public health problem that can become chronic and increase the risk of cancer. Live, mutated Salmonella is used to target cancer cells. However, few studies have addressed chronic Salmonella infection in vivo. AvrA is a Salmonella type-three secretion effector that is multifunctional, inhibiting intestinal inflammation and enhancing proliferation. ß-catenin is a key player in intestinal renewal, inflammation, and tumorigenesis. We hypothesize that in Salmonella-infected intestine, AvrA chronically activates the ß-catenin pathway and increases cell proliferation, thus deregulating the intestinal responses to bacterial infection. We followed mice with Salmonella infection for 27 wk and investigated the physiological effects and role of AvrA on ß-catenin in chronically infected intestine. We found that AvrA persistently regulated ß-catenin posttranslational modifications, including phosphorylation and acetylation. Moreover, the upstream regulator Akt, transcription factors, T cell factors, nuclear ß-catenin, and ß-catenin target genes were enhanced in mice infected with Salmonella-expressing AvrA. AvrA has a chronic functional role in promoting intestinal renewal. In summary, we have uncovered an essential role of Salmonella AvrA in chronically activating ß-catenin and impacting intestinal renewal in small intestine and colon. Our study emphasizes the importance of AvrA in chronic bacterial infection.

[Effect of anti-osteopontin antibody on expression of IL-2 and IL-5 in hepatic alveolar hydatid tissue of gerbil].

OBJECTIVE: To observe the effect of anti-osteopontin antibody on the level of IL-2 and IL-5 in the liver of gerbil infected with Echinococcus multilocularis (Em). METHODS: 180 gerbils were infected with echinococcus protoscoleces (approximately 400 for each gerbil) by abdominal opening inoculation in liver. The gerbils were randomly divided into three groups with 60 each: experiment group (group A, with anti-osteopontin antibody interference), control group (group B, with normal rabbit serum injection) and model group (group C, with no interference). Ten gerbils from each group were sacrificed at 20, 60, 100, 140, 180, and 220 days post-infection respectively. The liver tissue with hydatid cysts was collected and the expression of IL-2 and IL-5 was observed after immunohistochemistry staining (SP method). RESULTS: E. multilocularis hydatid tissue spreaded over the liver and abdominal cavity. The positive expression rate of IL-2 in the tissue showed no statistical difference among the three groups (P > 0.05). On the days 140 and 180, however, the positive expression rate of IL-5 in group A was 40% and 20% respectively, considerably lower than that in group B (100% and 90%) and group C (90% and 80% respectively). CONCLUSION: The anti-osteopontin antibody can reduce Th2 type cytokine response in the Em-infected gerbils, which may strengthen the immunity of the host.

Vitamin D Receptor Influences Intestinal Barriers in Health and Disease.

Vitamin D receptor (VDR) executes most of the biological functions of vitamin D. Beyond this, VDR is a transcriptional factor regulating the expression levels of many target genes, such as genes for tight junction proteins claudin-2, -5, -12, and -15. In this review, we discuss the progress of research on VDR that influences intestinal barriers in health and disease. We searched PubMed and Google Scholar using key words vitamin D, VDR, tight junctions, cancer, inflammation, and infection. We summarize the literature and progress reports on VDR regulation of tight junction distribution, cellular functions, and mechanisms (directly or indirectly). We review the impacts of VDR on barriers in various diseases, e.g., colon cancer, infection, inflammatory bowel disease, and chronic inflammatory lung diseases. We also discuss the limits of current studies and future directions. Deeper understanding of the mechanisms by which the VDR signaling regulates intestinal barrier functions allow us to develop efficient and effective therapeutic strategies based on levels of tight junction proteins and vitamin D/VDR statuses for human diseases.

Clinical Outcomes of Negative Balloon-Assisted Enteroscopy for Obscure Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis.

Background: For patients with obscure gastrointestinal bleeding (OGIB), finding the bleeding site is challenging. Balloon-assisted enteroscopy (BAE) has become the preferred diagnostic modality for OGIB. The long-term outcome of patients with negative BAE remains undefined. The present study aimed to evaluate the long-term outcomes of patients with negative BAE results for OGIB and to clarify the effect of further investigations at the time of rebleeding with a systematic review and meta-analysis of the available cohort studies. Methods: Studies were searched through the PubMed, EMBASE, and Cochrane library databases. The following indexes were analyzed: rebleeding rate after negative BAE, rebleeding rate after different follow-up periods, the proportion of patients who underwent further evaluation after rebleeding, the percentage of patients with identified rebleeding sources, and the percentage of patients with rebleeding sources in the small intestine. Heterogeneity was assessed using the I2 test. Results: Twelve studies that involved a total of 407 patients were included in the analysis. The pooled rebleeding rate after negative BAE for OGIB was 29.1% (95% CI: 17.2-42.6%). Heterogeneity was significant among the studies (I2 = 88%; p < 0.0001). The Chi-squared test did not show a difference in rebleeding rates between the short and long follow-up period groups (p = 0.142). The pooled proportion of patients who underwent further evaluation after rebleeding was 86.1%. Among the patients who underwent further evaluation, rebleeding sources were identified in 73.6% of patients, and 68.8% of the identified rebleeding lesions were in the small intestine. Conclusion: A negative result of BAE in patients with OGIB indicates a subsequently low risk of rebleeding. Further evaluation should be considered after rebleeding.

Effects of Melanized Bacteria and Soluble Melanin on the Intestinal Homeostasis and Microbiome In Vivo.

Radiation damage is associated with inflammation and immunity in the intestinal mucosa, including gut microbiota. Melanin has a unique capacity to coordinate a biological reaction in response to environmental stimuli, such as radiation exposure. Thus, melanin and melanized microbes have potential to be used for mitigation of injury induced by radiation. The purpose of the current study is to examine the safety of these agents for future targeting gut microbiome to prevent radiation-induced injury. We administered mice with soluble allomelanin and observed its effect on the intestinal physiology and body weight. We then established a melanized bacterial strain in probiotic E. coli Nissle. We measured the body weight of the mice treated with melanized E. coli Nissle. We showed the enhanced bacterial abundance and colonization of the melanized bacteria E. coli Nissle in the intestine. Melanized E. coli Nissle colonized the colon in less than 3 h and showed consistent colonization over 24 h post one oral gavage. We did not find significant changes of bodyweight in the mice treated with melanized bacteria. We did not observe any inflammation in the intestine. These results demonstrate the safety of soluble melanin and melanin-producing bacteria and will support the future studies to treat radiation-induced injuries and restore dysbiosis.

[Research progress on the relationship between osteopontin and hepatic echinococcosis].

Osteopontin is a negatively charged, hydrophilic secreted phosphorylated glycoprotein. It is synthesized and secreted by a variety of cells, and is found in various tissues and cells. The protein is similar in structure to matrix proteins, has the characteristics of cytokines in function and involved in a series of pathological processes. Recent studies confirmed that osteopontin is highly expressed in liver hydatid cyst and may play an important role in cyst formation.

[Inhibition of invasive growth and metastasis of hepatic alveolar echinococcosis by anti-osteopontin antibody].

OBJECTIVE: To observe the inhibitive effect on invasive growth and metastasis of Echinococcus multilocularis by exogenous anti-osteopontin (OPN) antibody. METHODS: 180 gerbils were infected with 20% E. multilocularis suspension (approximately 400 protoscoleces in 0.1 ml per gerbil) through abdominal opening injection in liver, and then divided into model group, experiment group and control group. Experiment group and control group each with 60 gerbils were injected via the tail vein with 0.15 ml of anti-OPN antibody (1:32) and rabbit serum, respectively. All gerbils in the two groups received injections, with 2-day interval for the first seven injections, and then at 7-day interval for the remaining injections. Model group were without any treatment. The three groups were subdivided into six groups each with 10 gerbils. The gerbils from each group were sacrificed on day 1, 20, 40, 60, 80, and 100 after infection, respectively. Hepatic echinococcus cyst and metastasis tissue were observed. The expression of OPN was measured by immunohistochemistry staining (SP method). Serum samples were collected at 100 d post-infection, and the content of OPN in sera was measured by ELISA. RESULTS: There were no significant difference in cyst weight and metastatic rate of thoracic lymph node among the three groups at 1, 20, 40, 60, and 80d post-infection (P > 0.05), while at 100 d postinfection, cyst weight and metastatic rate of thoracic lymph node in experiment group [(7.28 +/- 0.38) g, 20%] were lower than that of control group [(9.70 +/- 0.61) g, 70%] and model group [(932 +/- 0.73) g, 70%] (P < ). Expression of OPN was found at different levels in echinococcus cysts. OPN was located in the cytoplasm, and mainly distributed in the germinal layer. The OPN positive expression levels were not significantly different between experiment group and other groups on day 1, 20, 40, 60, and 80 afer infection ( >0 . 05). At 100d post-infection, OPN positive expression rate and serum OPN content in experimental group [20% and (30.90 +/- 2.25) ng/.l micro respectively] was lower than that of control group [80% and (41.03.2 +/- 76) nWng/micro and model group [80% and (42.39 +/- 2.85) nWng/micro (PdL < 0.). CONCLUSION: Anti-osteopontin antibody can reduce OPN concentration in hepatic echinococcus cyst and serum, and inhibit the invasive growth and metastasis of E. multilocularis.