NS6180, a new KCa3.1 channel inhibitor prevents T-cell activation and inflammation in a rat model of inflammatory bowel disease

Background and Purpose

The K_Ca3.1 channel is a potential target for therapy of immune disease. We identified a compound from a new chemical class of K_Ca3.1 inhibitors and assessed in vitro and in vivo inhibition of immune responses.

Experimental Approach

We characterized the benzothiazinone NS6180 (4-[[3-(trifluoromethyl)phenyl]methyl]-2H-1,4-benzothiazin-3(4H)-one) with respect to potency and molecular site of action on K_Ca3.1 channels, selectivity towards other targets, effects on T-cell activation as well as pharmacokinetics and inflammation control in colitis induced by 2,4-dinitrobenzene sulfonic acid, a rat model of inflammatory bowel disease (IBD).

Key Results

NS6180 inhibited cloned human K_Ca3.1 channels (IC₅₀ = 9 nM) via T250 and V275, the same amino acid residues conferring sensitivity to triarylmethanes such as like TRAM-34. NS6180 inhibited endogenously expressed K_Ca3.1 channels in human, mouse and rat erythrocytes, with similar potencies (15–20 nM). NS6180 suppressed rat and mouse splenocyte proliferation at submicrolar concentrations and potently inhibited IL-2 and IFN-γ production, while exerting smaller effects on IL-4 and TNF-α and no effect on IL-17 production. Antibody staining showed K_Ca3.1 channels in healthy colon and strong up-regulation in association with infiltrating immune cells after induction of colitis. Despite poor plasma exposure, NS6180 (3 and 10 mg·kg⁻¹ b.i.d.) dampened colon inflammation and improved body weight gain as effectively as the standard IBD drug sulfasalazine (300 mg·kg⁻¹ q.d.).

Conclusions and Implications

NS6180 represents a novel class of K_Ca3.1 channel inhibitors which inhibited experimental colitis, suggesting K_Ca3.1 channels as targets for pharmacological control of intestinal inflammation.     

Hypoallergenic formula with Lactobacillus rhamnosus GG for babies with colic: A pilot study of recruitment,retention, and fecal biomarkers

AIM: To investigate recruitment, retention, and estimates for effects of formula supplementation with Lactobacillus rhamnosus GG(LGG) on inflammatory biomarkers and fecal microbial community in infants with colic. METHODS: A prospective, double-blind, placebocontrolled trial was conducted in otherwise healthy infants with colic. We screened 74 infants and randomized and analyzed results in 20 infants [9 receiving LGG(LGG+) and 11 not receiving LGG(LGG-)]. LGG was incorporated in the formula(Nutramigen~#174;)(minimum of 3 × 107 CFU/d) in the LGG+ group. Fecal microbiota and inflammatory biomarkers, including fecal calprotectin(FC), plasma cytokines, circulating regulatory T cells(Tregs), and crying + fussing time were analyzed to determine optimal time points and effect sizes for a larger trial. RESULTS: Recruitment in this population was slow, with about 66% of eligible infants willing to enroll; subject retention was better(75%). These rates were influenced by parents' reluctance to volunteer their infant for a clinical trial and by their tendency to change formulas. The maximal difference of crying + fussing time was observed at day 14, comparing the 2 groups, with a mean difference of-91(95%CI:-76, 259) min(P = NS). FC showed no significant difference, but the optimal time to determine a potential effect was at day 90 [with a mean difference of 121(95%CI:-48, 291) μg/g stool], observing a lower level of FC in the LGG+ group. The fecal microbial communities were chaotic, as determined by Shannon's diversity index and not apparently influenced by the probiotic. No significant change was observed in plasma inflammatory cytokines or Tregs, comparing LGG+ to LGG- groups. CONCLUSION: Designing future colic trials involving a probiotic-supplemented formula for infants in the United States will require consideration for difficult enrollment. Infants with colic have major variations in feal microbiota and calprotectin, both of which improve with time, with optimal time points for measurement at days 14 and 90 after treatment.     

CLINICAL APPLICATION OF BOTULINUM TOXIN TYPE B IN MOVEMENT DISORDERS AND AUTONOMIC SYMPTOMS

B OTULINUM toxintypeA (BTX-A ) has been suc- cessfullyusedinthetreatmentofabnormal muscle contractionsand otherclinicalindications.Howev-er,some patientsreceivingrepeatedBTX-A injectionsloseresponsedue toimmunoresistance.1Botulinum toxintypeB(BTX-B ) isantigenicallydistinctfrom BTX-A , thusservingan importanttherapeuticalternativeforpatientswho becomeBTX-A resistant.Data from double-blinded,randomized,pl-acebo-controlledtrialsdemonstratedtheefficacyand safetyofBTX-B inpatientswit…     

Identification of the membrane glycoprotein that is the C3b receptor of the human erythrocyte, polymorphonuclear leukocyte, B lymphocyte, and monocyte

A human erythrocyte membrane glycoprotein of 205,000 mol wt (gp205) has been identified as the C3b receptor of the erythrocyte, polymorphonuclear leukocyte (PMN), B lymphocyte, and monocyte. Initially, gp205 was sought and characterized as a constituent of the human erythrocyte membrane that can impair activation of the alternative complement pathway by inducing loss of function of the properdin-stabilized amplification C3 convertase (C3b,Bb,P) through displacement of Bb from C3b and by promoting cleavage-inactivation of C3b by C3b inactivator. These inhibitory activities of gp205 suggested that this membrane glyeoprotein had an affinity for C3b and prompted an analysis of its possible identity as the C3b receptor of human peripheral blood cells. The F(ab’)2 fragment of rabbit IgG anti-gp205 inhibited the formation of rosettes with sheep EC3b of human erythroeytes, B lymphocytes, monocytes and PMN in a dose-response manner; the 50 percent inhibitory doses were 0.13/μg/ml, 0.90 μg/ml, 1.25 μg/ml, and 1.20 μg/ml of F(ab’)2, respectively. Anti-gp205 did not impair the formation of rosettes by monocytes and B lymphocytes with sheep EC3bi or with EC3d. Scatchard analysis of the number of specific (125)I-F(ab’)(2) anti-gp205 binding sites/cell revealed 950 sites/erythrocyte, 21,000 sites/cell of B lymphocyte preparation, 57,000 sites/PMN, and 48,000 sites/monocyte, indicating that the higher concentrations of antibody that had been required for inhibition of rosette formation by the nucleated cells reflected larger numbers of receptors on these cells. Direct evidence for the identity of gp205 as the C3b receptor of the four cell types was obtained when detergent-solubilized membrane proteins of the surface-radioiodinated cells were reacted with anti- gp205 and the immunoprecipitate was analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. In each instance, the antigenic material reacting with anti-gp205 represented a single protein with an apparent 205,000 mol wt. Thus, gp205 is the C3b receptor of human erythrocytes, PMN, B lymphocytes, and monocytes.     

Survival after out-of-hospital cardiac arrest,Viet Nam: multicentre prospective cohort study

ObjectiveTo investigate factors associated with survival after out-of-hospital cardiac arrest in Viet Nam.MethodsWe did a multicentre prospective observational study of people (> 18 years) presenting with out-of-hospital cardiac arrest (not caused by trauma) to three tertiary hospitals in Viet Nam from February 2014 to December 2018. We collected data on characteristics, management and outcomes of patients with out-of-hospital cardiac arrest and compared these data by type of transportation to hospital and survival to hospital admission. We assessed factors associated with survival to admission to and discharge from hospital using logistic regression analysis.FindingsOf 590 eligible people with out-of-hospital cardiac arrest, 440 (74.6%) were male and the mean age was 56.1 years (standard deviation: 17.2). Only 24.2% (143/590) of these people survived to hospital admission and 14.1% (83/590) survived to hospital discharge. Most cardiac arrests (67.8%; 400/590) occurred at home, 79.4% (444/559) were witnessed by bystanders and 22.3% (124/555) were given cardiopulmonary resuscitation by a bystander. Only 8.6% (51/590) of the people were taken to hospital by the emergency medical services and 32.2% (49/152) received pre-hospital defibrillation. Pre-hospital defibrillation (odds ratio, OR: 3.90; 95% confidence interval, CI: 1.54–9.90) and return of spontaneous circulation in the emergency department (OR: 2.89; 95% CI: 1.03–8.12) were associated with survival to hospital admission. Hypothermia therapy during post-resuscitation care was associated with survival to discharge (OR: 5.44; 95% CI: 2.33–12.74).ConclusionImprovements are needed in the emergency medical services in Viet Nam such as increasing bystander cardiopulmonary resuscitation and public access defibrillation, and improving ambulance and post-resuscitation care.     

Comparison of Computerized and Standard Visual Criteria of Exercise ECG for Diagnosis of Coronary Artery Disease

Objective: To review past and current studies of computerized exercise ECG criteria in order to establish which, if any, are superior to standard visual analysis for the diagnosis of coronary artery disease (CAD). Methods: Prior studies that compared multiple computerized ECG criteria were reviewed. In addition, we investigated two sets of patients that had both exercise testing and coronary arteriography at two university-affiliated Veteran's Affairs Medical Centers. Patients with previous myocardial infarction or coronary artery bypass surgery, valvular heart disease, left bundle branch block, or any diagnostic Q waves present on their resting ECGs were excluded from analysis. Sensitivity and specificity values were compiled for standard visual analysis and for the following computerized ECG criteria: ST0; ST60; ST slope; ST integral; ST index; R wave adjusted ST; ST/heart rate (HR) index; Hollenberg's Treadmill exercise score; and discriminant function analysis (DFA). Results: Despite the effects of limited challenge and work-up bias, the compiled results indicate that ST measurements recorded during the time of recovery from exercise are substantially more diagnostic than those recorded at maximal exercise. ST integral, ST60, and R wave adjusted ST60 during recovery are especially discriminating of CAD, while Hollenberg's treadmill exercise score is not. There were inconclusive results for HR adjustments to ST depression and ST index. DFA including visual analysis of the ECG consistently exhibited the greatest discriminating power of all computerized results. Conclusion: Although DFA, ST integral during recovery, or ST60 during recovery exhibited improved predictive value, further research is necessary before we can clearly offer a superior alternative to standard visual analysis.     

Characterizing Twitter Discussions About HPV Vaccines Using Topic Modeling and Community Detection

BackgroundIn public health surveillance, measuring how information enters and spreads through online communities may help us understand geographical variation in decision making associated with poor health outcomes.ObjectiveOur aim was to evaluate the use of community structure and topic modeling methods as a process for characterizing the clustering of opinions about human papillomavirus (HPV) vaccines on Twitter.MethodsThe study examined Twitter posts (tweets) collected between October 2013 and October 2015 about HPV vaccines. We tested Latent Dirichlet Allocation and Dirichlet Multinomial Mixture (DMM) models for inferring topics associated with tweets, and community agglomeration (Louvain) and the encoding of random walks (Infomap) methods to detect community structure of the users from their social connections. We examined the alignment between community structure and topics using several common clustering alignment measures and introduced a statistical measure of alignment based on the concentration of specific topics within a small number of communities. Visualizations of the topics and the alignment between topics and communities are presented to support the interpretation of the results in context of public health communication and identification of communities at risk of rejecting the safety and efficacy of HPV vaccines.ResultsWe analyzed 285,417 Twitter posts (tweets) about HPV vaccines from 101,519 users connected by 4,387,524 social connections. Examining the alignment between the community structure and the topics of tweets, the results indicated that the Louvain community detection algorithm together with DMM produced consistently higher alignment values and that alignments were generally higher when the number of topics was lower. After applying the Louvain method and DMM with 30 topics and grouping semantically similar topics in a hierarchy, we characterized 163,148 (57.16%) tweets as evidence and advocacy, and 6244 (2.19%) tweets describing personal experiences. Among the 4548 users who posted experiential tweets, 3449 users (75.84%) were found in communities where the majority of tweets were about evidence and advocacy.ConclusionsThe use of community detection in concert with topic modeling appears to be a useful way to characterize Twitter communities for the purpose of opinion surveillance in public health applications. Our approach may help identify online communities at risk of being influenced by negative opinions about public health interventions such as HPV vaccines.