GABA Production Through Acid Resistance Mechanisms in Escherichia coli

Escherichia coli, one of the most common gut microbes, must survive through the highly acidic environment of the stomach at a mean of pH 2 before reaching the intestines. One method by which E. coli survive the acidity is by expelling protons from the cell, raising the intracellular pH to a more viable level, most commonly with the decarboxylation of glutamate into γ-aminobutyric acid (GABA) via glutamate decarboxylase. The GABA expelled from the cell contains more protons than the glutamate or glutamine pumped in which, in turn, raises intracellular pH. Because GABA functions as a neurotransmitter in humans, excess or decreased expression of glutamate decarboxylase may yield behavioral effects. We aimed to investigate GABA production in different strains of laboratory-evolved E. coli after two hours of acid stress at pH 2 in media with varying concentrations of either glutamine or glutamate to further understand what happens to GABA production in different conditions. Statistical analysis reveals the addition of glutamine to the media yields a similar concentration of extracellular GABA as the addition of glutamate does (p=0.6527). Interestingly, none of the laboratory-evolved E. coli strains produced more GABA than the ancestral strain. Four strains evolved in pH 4.6 media lost all GABA production, as did two strains evolved in pH 6.5 media with benzoate. Three other benzoate-evolved strains showed reduced production of extracellular GABA when compared to the ancestral strain (p\u3c0.001). These results suggest variations in E. coli evolution under stress conditions may yield reduced production of GABA

Chaordic learning systems: reconceptualising pedagogy for the digital age

This article focuses on an explorative and experimental project seeking to implement Chaordic Learning Systems (CLS) as a pedagogic approach in Higher Education. We outline a project that embraced technologies of Web 2.0 to show how both physical and virtual spaces can be used to support and develop a strong and dynamic learning community in which staff and students work alongside each other to co-produce learning resources. Drawing on theories of Communities of Practice and Situated Learning a new teaching framework was introduced to a Level 5 undergraduate module (7.5 ECTS credits) that had not, until this project, used both face-to-face and online learning tools to engage students in the critical and discursive debates pertaining to sport and physical culture. We undertook this project with the belief that Higher Education should be concerned with answering the calls of an increasingly digital society for whom learning is not restricted by the physical boundaries of the university or the political landscape within which learning finds itself

Chaordic learning systems: reconceptualising pedagogy for the digital age

This article focuses on an explorative and experimental project seeking to implement Chaordic Learning Systems (CLS) as a pedagogic approach in Higher Education. We outline a project that embraced technologies of Web 2.0 to show how both physical and virtual spaces can be used to support and develop a strong and dynamic learning community in which staff and students work alongside each other to co-produce learning resources. Drawing on theories of Communities of Practice and Situated Learning a new teaching framework was introduced to a Level 5 undergraduate module (7.5 ECTS credits) that had not, until this project, used both face-to-face and online learning tools to engage students in the critical and discursive debates pertaining to sport and physical culture. We undertook this project with the belief that Higher Education should be concerned with answering the calls of an increasingly digital society for whom learning is not restricted by the physical boundaries of the university or the political landscape within which learning finds itself

Can we predict a national profile of non-attendance paediatric urology patients: a multi-institutional electronic health record study

Background Non-attendance at paediatric urology outpatient appointments results in the patient’s failure to receive medical care and wastes health care resources.Objective To determine the utility of using routinely collected electronic health record (EHR) data for multi-centre analysis of variables predictive of patient no-shows (NS) to identify areas for future intervention.Methods Data were obtained from Children’s Hospital Colorado, Rady Children’s Hospital San Diego and University of Virginia Hospital paediatric urology practices, which use the Epic® EHR system. Data were extracted for all urology outpatient appointments scheduled from 1 October 2010 to 30 September 2011 using automated electronic data extraction techniques. Data included appointment type; date; provider type and days from scheduling to appointment. All data were de-identified prior to analysis. Predictor variables identified using χ2 and analysis of variance were modelled using multivariate logistic regression.Results A total of 2994 NS patients were identified within a population of 28,715, with a mean NS rate of 10.4%. Multivariate logistic regression determined that an appointment with mid-level provider (odds ratio (OR) 1.70 95% CI (1.56, 1.85)) and an increased number of days between scheduling and appointment (15–28 days OR 1.24 (1.09, 1.41); 29+ days OR 1.70 (1.53, 1.89)) were significantly associated with NS appointments.Conclusion We demonstrated sufficient interoperability among institutions to obtain data rapidly and efficiently for use in 1) interventions; 2) further study and 3) more complex analysis. Demographic and potentially modifiable clinic characteristics were associated with NS to the outpatient clinic. The analysis also demonstrated that available data are dependent on the clinical data collection systems and practices

Motesanib inhibits Kit mutations associated with gastrointestinal stromal tumors

<p>Abstract</p> <p>Background</p> <p>Activating mutations in Kit receptor tyrosine kinase or the related platelet-derived growth factor receptor (PDGFR) play an important role in the pathogenesis of gastrointestinal stromal tumors (GIST).</p> <p>Methods</p> <p>This study investigated the activity of motesanib, an inhibitor of vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3; PDGFR; and Kit, against primary activating Kit mutants and mutants associated with secondary resistance to imatinib. Single- and double-mutant isoforms of Kit were evaluated for their sensitivity to motesanib or imatinib in autophosphorylation assays and in Ba/F3 cell proliferation assays.</p> <p>Results</p> <p>Motesanib inhibited Kit autophosphorylation in CHO cell lines expressing primary activating mutations in exon 9 (AYins503-504, IC₅₀= 18 nM) and exon 11 (V560 D, IC₅₀= 5 nM; Δ552-559, IC₅₀= 1 nM). Motesanib also demonstrated activity against kinase domain mutations conferring imatinib resistance (V560D/V654A, IC₅₀= 77 nM; V560D/T670I, IC₅₀= 277 nM; Y823 D, IC₅₀= 64 nM) but failed to inhibit the imatinib-resistant D816V mutant (IC₅₀> 3000 nM). Motesanib suppressed the proliferation of Ba/F3 cells expressing Kit mutants with IC₅₀values in good agreement with those observed in the autophosphorylation assays.</p> <p>Conclusions</p> <p>In conclusion, our data suggest that motesanib possesses inhibitory activity against primary Kit mutations and some imatinib-resistant secondary mutations.</p

Antivenom Treatment Is Associated with Fewer Patients using Opioids after Copperhead Envenomation

Introduction Copperhead envenomation causes local tissue destruction, leading people to seek treatment for the pain and swelling. First-line treatment for the pain is opioid medications. There is rising concern that an initial opioid prescription from the emergency department (ED) can lead to long-term addiction. This analysis sought to determine whether use of Fab antivenom (FabAV) for copperhead envenomation affected opioid use. Methods We performed a secondary analysis using data from a randomized clinical trial designed to determine the effect of FabAV on limb injury recovery following mild to moderate copperhead envenomation. Opioid use was a defined secondary outcome in the parent trial. Patients were contacted after discharge, and data were obtained regarding medications used for pain and the patients’ functional status. This analysis describes the proportion of patients in each treatment group reporting opioid use at each time point. It also assesses the interaction between functional status and use of opioids. Results We enrolled 74 patients in the parent trial (45 received FabAV, 29 placebo), of whom 72 were included in this secondary analysis. Thirty-five reported use of any opioids after hospital discharge. A smaller proportion of patients treated with FabAV reported opioid use: 40.9% vs 60.7% of those in the placebo group. The proportion of patients using opioids remained smaller in the FabAV group at each follow-up time point. Controlling for confounders and interactions between variables, the model estimated that the odds ratio of using opioids after hospital discharge among those who received placebo was 5.67 times that of those who received FabAV. Patients who reported higher baseline pain, those with moderate as opposed to mild envenomation, and females were more likely to report opioid use at follow-up. Patients with ongoing limitations to functional status had an increased probability of opioid use, with a stronger association over time. Opioid use corresponded with the trial’s predefined criteria for full recovery, with only two patients reporting opioid use in the 24 hours prior to achieving full limb recovery and no patients in either group reporting opioid use after full limb recovery. Conclusion In this study population, the proportion of patients using opioids for pain related to envenomation was smaller in the FabAV treatment group at all follow-up time points

The Efficacy of Crotalidae Polyvalent Immune Fab (Ovine) Antivenom Versus Placebo Plus Optional Rescue Therapy on Recovery From Copperhead Snake Envenomation: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial

Study objective: Copperhead snake (Agkistrodon contortrix) envenomation causes limb injury resulting in pain and disability. It is not known whether antivenom administration improves limb function. We determine whether administration of antivenom improves recovery from limb injury in patients envenomated by copperhead snakes. Methods: From August 2013 through November 2015, we performed a multicenter, randomized, double-blind, placebo- controlled, clinical trial to evaluate the effect of ovine Crotalidae polyvalent immune Fab (ovine) (CroFab; FabAV) antivenom therapy on recovery of limb function in patients with copperhead snake envenomation at 14 days postenvenomation. The study setting was 18 emergency departments in regions of the United States where copperhead snakes are endemic. Consecutive patients aged 12 years or older with mild- to moderate-severity envenomation received either FabAV or placebo. The primary outcome was limb function 14 days after envenomation, measured by the Patient-Specific Functional Scale. Additional outcomes included the Patient-Specific Functional Scale at other points; the Disorders of the Arm, Shoulder, and Hand, Lower Extremity Functional Scale, and Patient’s Global Impression of Change instruments; grip strength; walking speed; quality of life (Patient-Reported Outcomes Measurement Information System Physical Fucntion-10); pain; and analgesic use. Results: Seventy-four patients received study drug (45 FabAV, 29 placebo). Mean age was 43 years (range 12 to 86 years). Fifty-three percent were men, 62% had lower extremity envenomation, and 88% had mild initial severity. The primary outcome, the least square mean Patient-Specific Functional Scale score at 14 days postenvenomation, was 8.6 for FabAV-treated subjects and 7.4 for placebo recipients (difference 1.2; 95% confidence interval 0.1 to 2.3; P1�4.04). Additional outcome assessments generally favored FabAV. More FabAV-treated subjects experienced treatment- emergent adverse events (56% versus 28%), but few were serious (1 in each group). Conclusion: Treatment with FabAV reduces limb disability measured by the Patient-Specific Functional Scale 14 days after copperhead envenomation. [Ann Emerg Med. 2017;70:233-244.