The primary prevention of pancreatic fistula using a vascularised rectus abdominis muscle flap - A porcine model.

Background: A pancreatic fistula is one of the most devastating complications following a Whipple's procedure. Fistula rates remain high despite various modifications to surgical techniques. We propose the use of a vascularised muscle flap in the primary prevention of pancreatic fistulas. Method: A distal pancreatectomy was performed on 5 pigs in our porcine model. A pancreaticojejunal (PJ) anastomotic leak was simulated. The pigs were divided into treatment (4 pigs) and control groups (1 pig). A left pedicled rectus abdominis flap was wrapped around the PJ anastomosis for the treatment group and omitted for the control group. Serum and drain amylase levels were recorded. The PJ-rectus abdominis flap complex was evaluated histologically. Results: There was no biochemical evidence of anastomotic leak in the treatment group. The drain-serum amylase ratio was less than 1.5 in the treatment group (p=0.006). Microscopically, the muscle adjacent to the anastomotic leak showed mild necrotic changes with an affected muscle depth of less than 10%. Conclusion: The vascularised rectus abdominis muscle is a durable flap to withstand proteolytic pancreatic enzymes. It is able to provide a water-tight seal around the PJ anastomosis and mitigate intraperitoneal haemorrhage and infection caused by erosion from the pancreatic fistula.

Comparison of pharmacological thrombolysis with mechanical thrombectomy in thrombosed arteriovenous fistulas and grafts: a systemic review and meta-analysis.

AIM: To compare the effectiveness and safety of pharmacological thrombolysis and mechanical thrombectomy. MATERIAL AND METHODS: This review was conducted in accordance with the PRISMA guidelines. Pooled proportions and subgroup analysis were calculated for primary and secondary patency rates, technical success, clinical success, major and minor complications rates. RESULTS: This systematic review identified a total of 6,492 studies of which 17 studies were included for analysis. A total of 1,089 patients comprising 451 (41.4 %) and 638 (58.6 %) patients who underwent thrombolysis and mechanical thrombectomy procedures, respectively, were analysed. No significant differences were observed between thrombolysis and mechanical thrombectomy procedures in terms of technical success, clinical success, major and minor complications rates, primary and secondary patency rates; however, subgroup analysis of overall arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) demonstrated a significantly higher rate of major complications within the AVF group (p=0.0248). CONCLUSION: The present meta-analysis suggests that pharmacological thrombolysis and mechanical thrombectomy procedures are similarly effective and safe; however, AVFs are subject to higher major complications compared to AVGs.

Apparent diffusion coefficient and its standard deviation from diffusion-weighted imaging in preoperative predicting liver invasion by T3-staged resectable gallbladder carcinoma.

AIM: To evaluate apparent diffusion coefficient (ADC) and its standard deviation (SDADC) in preoperative predicting liver invasion by T3-staged gallbladder carcinoma (GBC). MATERIALS AND METHODS: Forty-one consecutive patients with T3-staged resectable GBC were included and divided into two sets with (n=27) and without (n=14) liver invasion. All patients underwent DWI at b-values of 0, 20, 50, 80, 100, 200, 400, 600, 800, and 1,000 s/mm2 with a 3 T magnetic resonance imaging scanner before surgery. ADC and SDADC of tumour-adjacent and tumour-distant liver tissues were measured on DWI, and were compared by Mann-Whitney U-tests. If there was a significant difference in any derived parameter, the area under the receiver operating characteristic curve (AUC) was used to assess performance of this parameter to predict liver invasion. RESULTS: DWI could differentiate between patients with and without liver invasion when b = 0, 1,000 s/mm2 (AUCs of ADC and SDADC were 0.697 and 0.714, respectively). In patients with liver invasion, mean ADC and SDADC of tumour-adjacent liver tissue were lower than of tumour-distant liver tissue when b = 0, 800 s/mm2, and = 0, 1,000 s/mm2 (all p-values <0.05). To differentiate tumour-adjacent from tumour-distant liver tissues in patients with liver invasion, AUCs of ADC were 0.687 (b = 0, 800 s/mm2) and 0.680 (b = 0, 1,000 s/mm2), and AUCs of SDADC were 0.673 (b = 0, 800 s/mm2) and 0.731 (b = 0, 1,000 s/mm2). CONCLUSIONS: DWI could have potential value in preoperative predicting liver invasion by T3-staged GBC.

[Clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors].

Objective: Cancer immunotherapy can lead to various side effects, termed immune-related adverse events (irAE). This study summarized and analyzed the clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI). Methods: This is a retrospective case series study involving 11 patients diagnosed with ILICI at the Peking Union Medical College Hospital from November 2019 to November 2021. Patient demographic information and clinical data, including gender, age, ILICI onset, clinical and radiological manifestations, pathological features, treatment, and resumption of ICI were retrospectively collected and analyzed. Results: The patients were primarily males (9/11) with a median age of 65 (range: 32-73) years. ICI mainly resulted in either partial remission (4/11) or stable disease (3/11). ILICI occurred after a median of two cycles of anti-programmed cell death-1 (PD-1) therapy, with a median time from the initial and last anti-PD-1 therapy to ILICI onset of 57 days and 17 days, respectively. ILICI was mostly severe (3/11) or very severe (6/11). While the clinical and radiological manifestations were non-specific, the pathological features were active lobular hepatitis and portal inflammation, with prominent CD8+T lymphocyte infiltration. The basic treatment was hepatoprotective drugs (10/11). Glucocorticoids were used as the primary therapy (9/11) but were ineffective in 4 of 9 cases. Of these, 3 of 9 cases received combined treatment with mycophenolate mofetil (MMF), only one of whom achieved remission. By the end of the study, 2 of 11 cases had resumed ICI and neither had experienced an ILICI relapse. Conclusion: The ILICI patients in this study had a corresponding history of ICI treatment and pathological features. The main treatment included hepatoprotective drugs and glucocorticoids. Immunosuppressive drugs were added for some cases but had poor efficacy.

[Application of acellular dermal matrix in periodontal soft tissue augmentation surgery].

The substitute materials of autologous tissue graft for periodontal soft tissue augmentation surgery develop rapidly. The use of substitute material can avoid the second operation area, shorten the operation time, reduce the postoperative reaction and pain, and is not limited by the quantity, suitable for a wide range of cases. In this paper, the characteristics, histological study, clinical application and therapeutic effect of acellular dermal matrix as a substitute material for autologous tissue transplantation were introduced to provide reference for clinical work.

Global Health System Resilience during Encounters with Stressors - Lessons Learnt from Cancer Services during the COVID-19 Pandemic.

AIMS: The protracted COVID-19 pandemic has overwhelmed health systems globally, including many aspects of cancer control. This has underscored the multidimensional nature of cancer control, which requires a more comprehensive approach involving taking a wider perspective of health systems. Here, we investigated aspects of health system resilience in maintaining cancer services globally during the COVID-19 pandemic. This will allow for health systems to be resilient to different types of system stressors/shocks in the future, to allow cancer care to be maintained optimally. MATERIALS AND METHODS: Using the World Health Organization health system framework (capturing aspects of service delivery, health workforce, information, medical products, vaccines and technologies, financing and governance and leadership), we carried out a comparative analysis of the impact of COVID-19 and the synthesis of the findings in responses in cancer care in 10 countries/jurisdictions across four continents comprising a wide diversity of health systems, geographical regions and socioeconomic status (China, Colombia, Egypt, Hong Kong SAR, Indonesia, India, Singapore, Sri Lanka, UK and Zambia). A combination of literature and document reviews and interviews with experts was used. RESULTS: Our study revealed that: (i) underlying weaknesses of health systems before the pandemic were exacerbated by the pandemic (e.g. economic issues in low- and middle-income countries led to greater shortage of medication and resource constraints compounded by inadequacies of public financing and issues of engagement with stakeholders and leadership/governance); (ii) no universal adaptive strategies were applicable to all the systems, highlighting the need for health systems to design emergency plans based on local context; (iii) despite the many differences between health systems, common issues were identified, such as the lack of contingency plan for pandemics, inadequate financial policies for cancer patients and lack of evidence-based approaches for competing priorities of cancer care/pandemic control. CONCLUSION: We identified four key points/recommendations to enhance the resilient capacity of cancer care during the COVID-19 pandemic and other system stressors: (i) effective pandemic control approaches in general are essential to maintain the continuity of cancer care during the emergency health crises; (ii) strong health systems (with sufficient cancer care resources, e.g. health workforce, and universal health coverage) are fundamental to maintain quality care; (iii) the ability to develop response strategies and adapt to evolving evidence/circumstances is critical for health system resilience (including introducing systematic, consistent and evidence-based changes, national support and guidance in policy development and implementation); (iv) preparedness and contingency plans for future public health emergencies, engaging the whole of society, to achieve health system resilience for future crises and to transform healthcare delivery beyond the pandemic.

Electrolyte imbalances as poor prognostic markers in COVID-19: a systemic review and meta-analysis.

PURPOSE: Serum electrolyte imbalances are highly prevalent in COVID-19 patients. However, their associations with COVID-19 outcomes are inconsistent, and of unknown prognostic value. We aim to systematically clarify the associations and prognostic accuracy of electrolyte imbalances (sodium, calcium, potassium, magnesium, chloride and phosphate) in predicting poor COVID-19 clinical outcome. METHODS: PubMed, Embase and Cochrane Library were searched. Odds of poor clinical outcome (a composite of mortality, intensive-care unit (ICU) admission, need for respiratory support and acute respiratory distress syndrome) were pooled using mixed-effects models. The associated prognostic sensitivity, positive and negative likelihood ratios (LR + , LR-) and predictive values (PPV, NPV; assuming 25% pre-test probability), and area under the curve (AUC) were computed. RESULTS: We included 28 observational studies from 953 records with low to moderate risk-of-bias. Hyponatremia (OR = 2.08, 95% CI = 1.48-2.94, I2 = 93%, N = 8), hypernatremia (OR = 4.32, 95% CI = 3.17-5.88, I2 = 45%, N = 7) and hypocalcemia (OR = 3.31, 95% CI = 2.24-4.88, I2 = 25%, N = 6) were associated with poor COVID-19 outcome. These associations remained significant on adjustment for covariates such as demographics and comorbidities. Hypernatremia was 97% specific in predicting poor outcome (LR + 4.0, PPV = 55%, AUC = 0.80) despite no differences in CRP and IL-6 levels between hypernatremic and normonatremic patients. Hypocalcemia was 76% sensitive in predicting poor outcome (LR- 0.44, NPV = 87%, AUC = 0.71). Overall quality of evidence ranged from very low to moderate. CONCLUSION: Hyponatremia, hypernatremia and hypocalcemia are associated with poor COVID-19 clinical outcome. Hypernatremia is 97% specific for a poor outcome, and the association is independent of inflammatory marker levels. Further studies should evaluate if correcting these imbalances help improve clinical outcome.

[Diagnostic value of different serological markers and correlation analysis with disease phenotype in inflammatory bowel disease].

Objective: To explore the diagnostic value of different serological markers and the correlation with disease phenotype in inflammatory bowel disease (IBD). Methods: The clinical data of 445 IBD patients in Peking Union Medical College Hospital from June 2010 to December 2020 were retrospectively collected, including 223 cases of ulcerative colitis (UC) [111 males, 112 females, with a median age of 46(20,79) years] and 222 cases of Crohn's disease (CD) [147 males, 75 females, with a median age of 39 (19, 72) years]. The positive rates of serum anti-neutrophil cytoplasmic antibodies (ANCA), anti-Saccharomyces cerevisiae antibodies (ASCA), goblet cell autoantibodies (GAB) and pancreatic autoantibodies (PAB) in the two groups were analyzed. The sensitivity, specificity, positive predictive value and negative predictive value of UC and CD were calculated. Logistic regression was performed to analyze the relationship between different combinations of antibodies and disease phenotype. Results: The positive rates of ASCA and PAB in CD patients were 34.7% (77/222) and 38.3% (85/222), respectively, which were higher than those in UC patients [10.3% (23/223) and 4.5% (10/223), P<0.001]. The positive rate of ANCA in UC patients was 50.2% (112/223), which was higher than that in CD patients [5.4% (12/222), P<0.001]. The positive rates of serum GAB in CD and UC patients were 21.6% (48/222) and 28.3% (63/223), respectively, with no significant difference (P=0.760). In patients with CD, the sensitivity of mono-marker ASCA (+), dual-marker ASCA (+) ANCA (-), quadruple-marker ASCA (+) ANCA (-) PAB (+) GAB (-) in diagnosing CD was 34.7%, 32.9%, 20.7%, the specificity was 89.7%, 95.5%, 100.0%, the positive predictive value was 77.0%, 90.1%, 100.0%, and the negative predictive value was 58.0%, 58.7%, 55.9%, respectively. In patients with UC, the sensitivity of mono-marker ANCA (+), dual-marker ANCA (+) ASCA (-), quadruple-marker ANCA (+) ASCA (-) PAB (-) GAB (+) in diagnosing UC was 50.2%, 40.4%, 24.2%, the specificity was 94.6%, 95.5%, 100.0%, the positive predictive value was 90.3%, 90.0%, 100.0%, and the negative predictive value was 65.4%, 61.4%, 56.8%, respectively. Mono-marker ASCA (+) (OR=3.39, 95%CI: 1.59-7.21), dual-marker ASCA (+) ANCA (-) (OR=2.87, 95%CI: 1.34-6.14), triple-marker ASCA (+) ANCA (-) GAB (-) (OR=3.09, 95%CI: 1.31-7.31) and quadruple-marker ASCA (+) ANCA (-) PAB (+) GAB (-) (OR=3.15, 95%CI: 1.56-8.03) were associated with stenosis and/or penetrating type CD. The mono-marker ANCA (+) (OR=2.69, 95%CI: 1.42-5.12) and dual-marker ANCA (+) ASCA (-) (OR=2.11, 95%CI: 1.03-4.16) were associated with extensive colonic lesions in UC. Conclusion: Based on ASCA or ANCA, the combination with PAB or GAB, is conducive to IBD diagnosis, and is associated with stenosis and/or penetrating type of CD and extensive type of UC.

[Risk factors and characteristics of gut microbiota and metabolites in inflammatory bowel diseases patients with urolithiasis].

Objective: To identify the related factors and characteristics of gut microbiota and metabolites in inflammatory bowel disease (IBD) patients with urolithiasis. Methods: A total of 68 IBD patients with urolithiasis and 136 gender-and age-matched IBD patients without urolithiasis in the Department of Gastroenterology, Peking Union Medical College Hospital from January 2014 to December 2019 were recruited. The diagnosis of urolithiasis was confirmed by plain films, ultrasonography, abdominal computed tomography or intravenous urography. The clinical data of patients were collected, and the association between the clinical characteristics and urolithiasis was further analyzed. The fecal samples were collected from 10 patients with urolithiasis and 18 patients without urolithiasis, and the gut microbiota and metabolites composition were analyzed. Results: There were 49 male and 19 female IBD patients with urolithiasis, with a mean age of (36.0±12.4) years, and 98 male and 38 female patients without urolithiasis, with a mean age of (36.1±12.5) years. Univariate analysis revealed that the rate of ileostomy and the resection of small intestine in Crohn's disease (CD) patients with urolithiasis (n=34) was significantly higher than CD patients without urolithiasis (n=68) (26.5% vs 7.4%, P=0.019). And the erythrocyte sedimentation rate was also higher [26.5 (12.0, 40.8) vs 13.0 (7.2, 32.5) mm/1 h, P=0.022] in CD patients with urolithiasis. There were no significant differences in clinical characteristics and biochemical parameters between the ulcerative colitis (UC) patients with urolithiasis (n=34) and without urolithiasis (n=68) (all P>0.05). The multivariate logistic regression analysis indicated that ileostomy and the resection of small intestine were the independent related factors for urolithiasis in CD patients (OR=4.619, 95%CI: 1.178-18.111, P=0.028). There was no significant difference in α and ß diversity between the two groups (all P>0.05). At the phylum level, there was no significant difference in the abundance of microbiota (all P>0.05). At the genus level, the abundance of Enterococcus (P=0.049), Eubacterium_eligens (P=0.036) was significantly decreased. At the species level, the abundance of Bacteroides_coprocola was increased in urolithiasis group (P=0.035), while the abundance of Blautia_caecimuris was significantly decreased (P=0.042). No significant difference was found in fecal metabolites between the two groups (all P>0.05). According to LDA effect size (Lefse) analysis, taxa including Sphingomonadales, Fenollaria, Bacteroides_coprocola contributed greatly to the difference between the two groups. Conclusions: Ileostomy and the resection of small intestine are related factors for urolithiasis in patients with CD. Gut microbiota may be involved in the occurrence of urolithiasis in patients with IBD.

Functional assessment of military aircrew applicants in a hypobaric chamber.

BACKGROUND: Aircrew are exposed to environmental pressure changes. In the Republic of Singapore Air Force (RSAF), applicants assessed to be at intermediate risk of otic barotrauma undergo a hypobaric chamber assessment ["trial of chamber" (TOC)] to functionally evaluate their suitability for military aircrew vocations. AIMS: To identify factors associated with TOC failure among applicants with otorhinolaryngological conditions. METHODS: All applicants to RSAF aircrew vocations who were assessed to be at intermediate risk of otic barotrauma over a 3-yr period were identified using the RSAF Aeromedical Centre's electronic database. Their medical records, as well as the TOC assessment records of the subset of applicants who underwent TOC, were reviewed for demographic data, clinical findings, and TOC outcomes. RESULTS: Of the 483 identified applicants, 374 (77%) had abnormal otoscopic findings, 103 (21%) had rhinitis symptoms, and 6 (1%) had previous ENT surgery. 123 (25%) underwent TOC, of which 20 (16%) failed. Holding other predictor variables constant, the odds of TOC failure increased by 0.79 per unit decrease in BMI (95% CI 0.63-0.99), and the odds of TOC failure increased by 0.93 per kg decrease in body weight (95% CI 0.87-1.00). An abnormal tympanogram was not a statistically significant predictor of TOC failure (OR 1.96, 95% CI 0.59-6.42). Of the 47 applicants who passed TOC and were eventually recruited, none subsequently developed otic barotrauma (mean follow-up, 3.3 yr ± 1.5 yr). CONCLUSIONS: Applicants with lower weight and BMI are more likely to develop otic barotrauma with environmental pressure change. Tympanometry cannot be reliably used to identify applicants who would more likely pass TOC.

The clinical landscape of cell-free DNA alterations in 1671 patients with advanced biliary tract cancer.

BACKGROUND: Targeted therapies have transformed clinical management of advanced biliary tract cancer (BTC). Cell-free DNA (cfDNA) analysis is an attractive approach for cancer genomic profiling that overcomes many limitations of traditional tissue-based analysis. We examined cfDNA as a tool to inform clinical management of patients with advanced BTC and generate novel insights into BTC tumor biology. PATIENTS AND METHODS: We analyzed next-generation sequencing data of 2068 cfDNA samples from 1671 patients with advanced BTC generated with Guardant360. We carried out clinical annotation on a multi-institutional subset (n = 225) to assess intra-patient cfDNA-tumor concordance and the association of cfDNA variant allele fraction (VAF) with clinical outcomes. RESULTS: Genetic alterations were detected in cfDNA in 84% of patients, with targetable alterations detected in 44% of patients. Fibroblast growth factor receptor 2 (FGFR2) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, and BRAF V600E were clonal in the majority of cases, affirming these targetable alterations as early driver events in BTC. Concordance between cfDNA and tissue for mutation detection was high for IDH1 mutations (87%) and BRAF V600E (100%), and low for FGFR2 fusions (18%). cfDNA analysis uncovered novel putative mechanisms of resistance to targeted therapies, including mutation of the cysteine residue (FGFR2 C492F) to which covalent FGFR inhibitors bind. High pre-treatment cfDNA VAF was associated with poor prognosis and shorter response to chemotherapy and targeted therapy. Finally, we report the frequency of promising targets in advanced BTC currently under investigation in other advanced solid tumors, including KRAS G12C (1.0%), KRAS G12D (5.1%), PIK3CA mutations (6.8%), and ERBB2 amplifications (4.9%). CONCLUSIONS: These findings from the largest and most comprehensive study to date of cfDNA from patients with advanced BTC highlight the utility of cfDNA analysis in current management of this disease. Characterization of oncogenic drivers and mechanisms of therapeutic resistance in this study will inform drug development efforts to reduce mortality for patients with BTC.

[Thrombotic occlusion of the extracorporeal circulation during hepatic chemosaturation despite targeted anticoagulation : A case report]. / Thrombotischer Verschluss der extrakorporalen Zirkulation während hepatischer Chemosaturation trotz zielgerechter Antikoagulation : Ein Fallbericht.

Percutaneous hepatic chemosaturation is a treatment option for unresectable primary or secondary liver tumors. In this procedure the part of the inferior vena cava (VCI) that collects blood from the hepatic veins is isolated using a double balloon catheter. Like this, systemic distribution of the chemotherapeutic agent melphalan which is administered via the hepatic artery can be prevented. After passage through the liver and drainage from the retrohepatic VCI, the chemosaturated blood passes through two extracorporeal filters. Subsequently, the filtered blood is returned via the jugular vein. The procedure is often accompanied by severe hemodynamic instability, the cause of which is still not completely understood. In addition, coagulation management of extracorporeal circulation is often challenging. The authors report a case in which a thrombus formed in the returning leg of the extracorporeal circulation despite sufficient activated clotting time (ACT). Targeted problem search and resolution were necessary simultaneously to hemodynamic stabilization and interdisciplinary collaboration to successfully perform the intervention and provide the patient with safe treatment.

Failure of sterilization in a dental outpatient facility: Investigation, risk assessment, and management.

In 2017, an incident of failed sterilization of dental instruments occurred at a large dental outpatient facility in Singapore. We aim to describe findings of the investigation of the sterilization breach incident, factors related to risk of viral transmission to the potentially affected patients, and the contact tracing process, patient management, and blood test results at a 6-month follow-up. A full assessment of the incident was immediately carried out. The factors related to risk of viral transmission due to affected instruments were analyzed using 3 keys points: breached step(s) and scale of the incident, prevalence of underlying bloodborne diseases and immunity in the Singapore population, health status of potential source patients, and type of dental procedure performed, and health status of affected patients and type of dental procedure received. Up to 72 affected instrument sets were used in 714 potentially affected patients who underwent noninvasive dental procedures. The investigation revealed that there was a lapse in the final step of steam sterilization, resulting in the use of incompletely sterilized items. The assessment determined that there was an extremely low risk of bloodborne virus transmission of diseases to the patients. At the 6-month follow-up, there were no infected/colonized cases found related to the incident. Lapses in the sterilization process for medical and dental instruments can happen, but a risk assessment approach is useful to manage similar incidents. Quick response and proper documentation of the sterilization process can prevent similar incidents.

Deeper may not be better: relationship between catheter dysfunction and location of the catheter tip in right-sided tunnelled haemodialysis catheters.

AIM: To examine the relationship between catheter tip location and catheter dysfunction in the context of tunnelled central venous catheters (CVCs) for haemodialysis. MATERIALS AND METHODS: This was a retrospective study of 993 haemodialysis patients who underwent insertion of tunnelled CVCs of step-tip design via the right internal jugular vein (IJV). Based on intra-procedural radiographs, the catheter tip was characterised as being in the superior vena cava (SVC), cavo-atrial junction (CAJ), or deep right atrium (DRA). Patients were tracked for 90 days post-procedure for complications resulting in catheter replacement, and these were compared between cohorts. Statistical analysis was performed with Pearson's chi-square and Fisher's exact tests for categorical variables and two-sample t-test and one-way analysis of variance (ANOVA) for continuous variables. RESULTS: Ninety-five patients (9.6%) experienced catheter dysfunction necessitating replacement within 90 days of insertion. Tip location in SVC was associated with lower occurrence of catheter dysfunction (1.9%) as compared with the CAJ (8%) and DRA (11%; p=0.049). Catheter replacement due to other complications (catheter-associated bacteraemia, cuff dislodgement, exit-site infection, external catheter damage) showed no statistically significant relation to location of the CVC tip. CONCLUSION: When utilising tunnelled CVCs with a step-tip design inserted via the right IJV, location of the catheter tip in the SVC is associated with reduced occurrence of catheter dysfunction as compared to either the CAJ or DRA.

[Coactivator p300-induced H3K27 acetylation mediates lipopolysaccharide-induced inflammatory mediator synthesis].

OBJECTIVE: To investigate the role of acetylated modification induced by coactivator p300 in lipopolysaccharide (LPS)- induced inflammatory mediator synthesis and its molecular mechanism. METHODS: Agilent SurePrint G3 Mouse Gene Expression V2 microarray chip and Western blotting were used to screen the molecules whose expression levels in mouse macrophages (RAW246.7) were correlated with the stimulation intensity of LPS. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (chip-qPCR) were used to verify the binding of the molecules to the promoters of IL-6 and TNF-α genes. The effects of transfection of RAW246.7 cells with overexpression or interfering plasmids on IL-6 and TNF-α synthesis were evaluated with ELISA, and the binding level of the target molecules and acetylation level of H3K27 in the promoter region of IL-6 and TNF-α genes were analyzed by chromatin immunoprecipitation sequencing technique (chip-seq). RESULTS: Gene microarray chip data and Western blotting both confirmed a strong correlation of p300 expression with the stimulation intensity of LPS. Immunocoprecipitation confirmed the binding between p300 and c-myb. The results of EMSA demonstrated that c-myb (P < 0.05), but not p300, could directly bind to the promoter region of IL-6 and TNF-α genes; p300 could bind to the promoters only in the presence of c-myb (P < 0.05). The expressions of p65, p300 and c-myb did not show interactions. Both p300 overexpression and LPS stimulation could increase the level of promoter-binding p300 and H3K27 acetylation level, thus promoting p65 binding and inflammatory gene transcription; such effects were obviously suppressed by interference of c-myb expression (P < 0.05). Interference of p65 resulted in inhibition of p65 binding to the promoters and gene transcription (P < 0.05) without affecting p300 binding or H3K27 acetylation level. CONCLUSION: LPS can stimulate the synthesis of p300, whose binding to the promoter region of inflammatory genes via c-myb facilitates the cohesion of p65 by inducing H3K27 acetylation, thus promoting the expression of the inflammatory genes.

Genetic and epigenetic determinants of reactivation of Mecp2 and the inactive X chromosome in neural stem cells.

Rett syndrome may be treated by reactivating the silent copy of Mecp2 from the inactive X chromosome in female cells. Most studies that model Mecp2 reactivation have used mouse fibroblasts rather than neural cells, which would be critical for phenotypic reversal, and rely on fluorescent reporters that lack adequate sensitivity. Here, we present a mouse model based on a dual bioluminescent and fluorescent reporter to assess the level of reactivation of Mecp2 and the inactive X chromosome by treating neural stem cells with 5-azacytidine and Xist knockdown. We show that reactivation of Mecp2 and other X-linked genes correlates with CpG density, with distance from escapees, and, very strongly, with the presence of short interspersed nuclear elements. In addition, X-linked genes reactivated in neural stem cells overlap substantially with early reactivating genes by induced pluripotent stem cell reprogramming of fibroblasts or neuronal progenitors, indicating that X chromosome reactivation follows similar paths regardless of the technique or cell type used.