IL-1R1 signaling in TBI: assessing chronic impacts and neuroinflammatory dynamics in a mouse model of mild closed-head injury.

Neuroinflammation contributes to secondary injury cascades following traumatic brain injury (TBI), with alternating waves of inflammation and resolution. Interleukin-1 (IL-1), a critical neuroinflammatory mediator originating from brain endothelial cells, microglia, astrocytes, and peripheral immune cells, is acutely overexpressed after TBI, propagating secondary injury and tissue damage. IL-1 affects blood-brain barrier permeability, immune cell activation, and neural plasticity. Despite the complexity of cytokine signaling post-TBI, we hypothesize that IL-1 signaling specifically regulates neuroinflammatory response components. Using a closed-head injury (CHI) TBI model, we investigated IL-1's role in the neuroinflammatory cascade with a new global knock-out (gKO) mouse model of the IL-1 receptor (IL-1R1), which efficiently eliminates all IL-1 signaling. We found that IL-1R1 gKO attenuated behavioral impairments 14 weeks post-injury and reduced reactive microglia and astrocyte staining in the neocortex, corpus callosum, and hippocampus. We then examined whether IL-1R1 loss altered acute neuroinflammatory dynamics, measuring gene expression changes in the neocortex at 3, 9, 24, and 72 h post-CHI using the NanoString Neuroinflammatory panel. Of 757 analyzed genes, IL-1R1 signaling showed temporal specificity in neuroinflammatory gene regulation, with major effects at 9 h post-CHI. IL-1R1 signaling specifically affected astrocyte-related genes, selectively upregulating chemokines like Ccl2, Ccl3, and Ccl4, while having limited impact on cytokine regulation, such as Tnfα. This study provides further insight into IL-1R1 function in amplifying the neuroinflammatory cascade following CHI in mice and demonstrates that suppression of IL-1R1 signaling offers long-term protective effects on brain health.

Inflammatory Regulation of CNS Barriers After Traumatic Brain Injury: A Tale Directed by Interleukin-1.

Several barriers separate the central nervous system (CNS) from the rest of the body. These barriers are essential for regulating the movement of fluid, ions, molecules, and immune cells into and out of the brain parenchyma. Each CNS barrier is unique and highly dynamic. Endothelial cells, epithelial cells, pericytes, astrocytes, and other cellular constituents each have intricate functions that are essential to sustain the brain's health. Along with damaging neurons, a traumatic brain injury (TBI) also directly insults the CNS barrier-forming cells. Disruption to the barriers first occurs by physical damage to the cells, called the primary injury. Subsequently, during the secondary injury cascade, a further array of molecular and biochemical changes occurs at the barriers. These changes are focused on rebuilding and remodeling, as well as movement of immune cells and waste into and out of the brain. Secondary injury cascades further damage the CNS barriers. Inflammation is central to healthy remodeling of CNS barriers. However, inflammation, as a secondary pathology, also plays a role in the chronic disruption of the barriers' functions after TBI. The goal of this paper is to review the different barriers of the brain, including (1) the blood-brain barrier, (2) the blood-cerebrospinal fluid barrier, (3) the meningeal barrier, (4) the blood-retina barrier, and (5) the brain-lesion border. We then detail the changes at these barriers due to both primary and secondary injury following TBI and indicate areas open for future research and discoveries. Finally, we describe the unique function of the pro-inflammatory cytokine interleukin-1 as a central actor in the inflammatory regulation of CNS barrier function and dysfunction after a TBI.

An active avoidance behavioral paradigm for use in a mild closed head model of traumatic brain injury in mice.

BACKGROUND: A mild traumatic brain injury (TBI) occurs to millions of people each year. Translational approaches to understanding the pathogenesis of neurological diseases and the testing of the effectiveness of interventions typically require cognitive function assays in rodents. NEW METHODS: Our goal was to validate the active avoidance task using the GEMINI avoidance system in a mouse model of mild closed head injury (CHI). RESULTS: We found that shock intensity had only a marginal effect on the test. We found that sex was an important biological variable, as female mice learned the task better than male mice. We demonstrate that a single mild CHI in mice caused deficits in the task at four weeks post-injury. COMPARISON WITH EXISTING METHODS: Active avoidance is a classical conditioning test in which mice must pair the presence of a conditioned stimulus with moving between two chambers to avoid an electric shock. External conditions (i.e., apparatus), as well as inherent differences in the mice, which may not be directly linked to the model of the disease (i.e., sensory differences), can affect the reproducibility of a behavioral assay. Before our study, there was a lack of standard operating procedures and validated methods for the active avoidance behavior for phenotyping mouse models of injury and disease. CONCLUSION: We offer a method for validating the active avoidance test, and a standard operating procedure, which will be useful in other models of neurological injury and disease.

Rotational assisted endoscopic retrograde cholangiopancreatography in patients with reconstructive gastrointestinal surgical anatomy.

AIM: To evaluate the success rates of performing therapy utilizing a rotational assisted enteroscopy device in endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy patients. METHODS: Between June 1, 2009 and November 8, 2012, we performed 42 ERCPs with the use of rotational enteroscopy for patients with altered anatomy (39 with gastric bypass Roux-en-Y, 2 with Billroth II gastrectomy, and 1 with hepaticojejunostomy associated with liver transplant). The indications for ERCP were: choledocholithiasis: 13 of 42 (30.9%), biliary obstruction suggested on imaging: 20 of 42 (47.6%), suspected sphincter of Oddi dysfunction: 4 of 42 (9.5%), abnormal liver enzymes: 1 of 42 (2.4%), ascending cholangitis: 2 of 42 (4.8%), and bile leak: 2 of 42 (4.8%). All procedures were completed with the Olympus SIF-Q180 enteroscope and the Endo-Ease Discovery SB overtube produced by Spirus Medical. RESULTS: Successful visualization of the major ampulla was accomplished in 32 of 42 procedures (76.2%). Cannulation of the bile duct was successful in 26 of 32 procedures reaching the major ampulla (81.3%). Successful therapeutic intervention was completed in 24 of 26 procedures in which the bile duct was cannulated (92.3%). The overall intention to treat success rate was 64.3%. In terms of cannulation success, the intention to treat success rate was 61.5%. Ten out of forty two patients (23.8%) required admission to the hospital after procedure for abdominal pain and nausea, and 3 of those 10 patients (7.1%) had a diagnosis of post-ERCP pancreatitis. The average hospital stay was 3 d. CONCLUSION: It is reasonable to consider an attempt at rotational assisted ERCP prior to a surgical intervention to alleviate biliary complications in patients with altered surgical anatomy.

Transient flare of ulcerative colitis after fecal microbiota transplantation for recurrent Clostridium difficile infection.

Clostridium difficile infection (CDI) is a common cause of infectious diarrhea and is usually treated with metronidazole or vancomycin. CDI recurs in 15%-30% of patients after the initial episode and in up to 65% after a second episode. Recurrent infections are a challenge to treat, and patients are usually managed with prolonged pulsed or tapered vancomycin. Fecal microbiota transplantation is an alternative treatment that has a 91% rate of success worldwide, with no reported complications. We describe a patient with ulcerative colitis that had been quiescent for more than 20 years who developed a flare of ulcerative colitis after fecal microbiota transplantation, indicating the need for caution in treating CDI with fecal microbiota transplantation in patients with inflammatory bowel disease.

Will H. pylori stagger under the weight of this LOAD? A novel but expensive eradication regimen.

In the era of increasing Helicobacter pylori resistance to clarithromycin and metronidazole used in standard treatments, newer well-tolerated regimens with high eradication success rates in practice are urgently needed. In this edition of the American Journal of Gastroenterology, a clinical trial of a novel drug combination is presented, demonstrating significantly more success in comparison with a standard "triple therapy." The new regimen (referred to as LOAD) comprises three antibiotics, levofloxaxin, doxycycline, and nitazoxanide, together with omeprazole. The LOAD regimen had around a 90% eradication rate compared with only 73% with a standard "triple therapy" regimen of amoxicillin, clarithromycin, and lansoprazole. The use of this relatively expensive novel drug combination would represent an absolute increased eradication rate of 17%, with a number needed to treat to achieve one more successful eradication of 5.88. Results from this preliminary study should prompt further evaluation of LOAD in rigorously designed clinical studies.

The STARK study: a cross-sectional study of adherence to short-term drug regiments in urban Kenya.

The purpose of the STARK study (Short-Term Adherence Research in Kenya) was to identify factors that predict adherence to short-term drug regimens in Nairobi, Kenya. The participants (N = 357) in the study were recruited from the RAFIKI Foundation Clinic, a free primary healthcare clinic in Kibera, Nairobi's largest slum. Quantitative surveys were administered to all the participants regarding their adherence patterns and to a subgroup of mothers (N = 233) regarding their adherence in giving medicine to their children. 40 participated in four focus groups. 52% of participants reported taking all of their prescribed medication and 47% took it until they felt better. Over 65% of mothers reported giving all prescribed medication to their children. The most frequently cited barriers to adherence included lack of food and clean water, stress, and financial problems. By identifying obstacles to adherence and strategies to overcome them, this study showed that a community- based clinic with committed healthcare workers in Kenya can empower an economically disadvantaged population to be adherent.

Comparison of the CFTR mutation spectrum in three cohorts of patients of Celtic origin from Brittany (France) and Ireland.

This study aims to compare the spectrum of the mutations identified in the gene responsible for cystic fibrosis in three cohorts of patients of Celtic origin from Brittany and Ireland. It included 389 patients from Brittany, 631 from Dublin and 139 from Cork. The CFTR gene analysis relied on the detection of the most common mutations, followed by a complete gene scanning using DGGE or D-HPLC. High mutation detection rates were obtained in each cohort: 99.6%, 96.8%, and 96.0% respectively. A high frequency of the c.1652_1655 del3 mutation (F508del: 74.8% to 81.3%) and of the "Celtic" mutation (c.1784G>A (G551D): 3.7% to 9.7%) was observed in each population. Apart from this, the mutation spectrums differed. In Brittany, the most common abnormalities were: c.1078delT (3.6%), c.4041C>G (N1303K: 1.4%), c.2670G>A (W846X(2): 1.0%) and c.1717-1G>A (1.0%), whereas in the cohort of Dublin, the main mutations were: c.482G>A (R117H: 3.0%), c.1811G>C (R560T: 2.4%) and c.621+1G>T (1.7%). Finally, in the Cork area, only the c.482G>A mutation (R117H) reached a frequency of 1%. Two previously-unreported mutations were identified in the Dublin cohort: c.2623-2A>G and c.3446T>G (M1105R). This collaborative study highlights the similarities of the CFTR alleles in the Breton and Irish populations, but also the disparities that exist between these populations, despite their common origin. Each population has its own history, with its mixture of founder effects and genetic drifts, which are at the origin of the current mutation distribution. The molecular study of the CFTR gene provides new tools for retracing European populations' histories.