Search

Background We previously conducted the Probiotic Regimen for Outpatient Gastroenteritis Utility of Treatment (PROGUT) study, which identified no improvements in children with acute gastroenteritis (AGE) administered a probiotic. However, the aforementioned study did not evaluate immunomodulatory benefits. Objectives The object of this study was to determine if stool secretory immunoglobulin A (sIgA) concentrations in children with AGE increase more among participants administered a Lactobacillus rhamnosus / helveticus probiotic compared with those administered placebo. Methods This a priori planned multicenter, randomized, double-blinded, placebo-controlled ancillary study enrolled children presenting for emergency care who received a 5-d probiotic or placebo course. Participants submitted stool specimens on days 0, 5, and 28. The primary endpoint was the change in stool sIgA concentrations on day 5 compared with baseline. Results A total of 133 (n  = 66 probiotic, 67 placebo) of 886 PROGUT participants (15.0%) provided all 3 specimens. Median stool sIgA concentrations did not differ between the probiotic and placebo groups at any of the study time points: day 0 median (IQR): 1999 (768, 4071) compared with 2198 (702, 5278) (P  = 0.27, Cohen's d  = 0.17); day 5: 2505 (1111, 5310) compared with 3207 (982, 7080) (P  = 0.19, Cohen's d  = 0.16); and day 28: 1377 (697, 2248) compared with 1779 (660, 3977) (P  = 0.27, Cohen's d  = 0.19), respectively. When comparing measured sIgA concentrations between days 0 and 5, we found no treatment allocation effects [β: −0.24 (−0.65, 0.18); P  = 0.26] or interaction between treatment and specimen collection day [β: −0.003 (−0.09, 0.09); P  = 0.95]. Although stool sIgA decreased between day 5 and day 28 within both groups (P  < 0.001), there were no differences between the probiotic and placebo groups in the median changes in sIgA concentrations when comparing day 0 to day 5 median (IQR) [500 (−1135, 2362) compared with 362 (−1122, 4256); P  = 0.77, Cohen's d  = 0.075] and day 5 to day 28 [−1035 (−3130, 499) compared with −1260 (−4437, 843); P  = 0.70, Cohen's d  = 0.067], respectively. Conclusions We found no effect of an L. rhamnosus / helveticus probiotic, relative to placebo, on stool IgA concentrations. This trial was registered at clinicaltrials.gov as NCT01853124. [ABSTRACT FROM AUTHOR]

Abstract: The receptor for advanced glycation end-product (RAGE) is the signal transduction receptor which senses a variety of signalling molecules including advanced glycation end products (AGEs), HMGB1, S100/calgranulins, β-amyloid, phosphatidylserine, C3a and advanced oxidation protein products (AOPPs). It is usually abnormally up-regulated and plays crucial roles during the development of many human diseases such as diabetes, cardiovascular diseases, osteoarthritis and cancer. RAGE regulates a number of cell processes of pivotal importance like inflammation, apoptosis, proliferation and autophagy. Therapeutic strategies to block RAGE may represent great therapeutic potentials and therefore it has been under extensive investigation during the last decade. Accordingly, there is a growing interest of unraveling the intracellular signalling pathways by which RAGE controls these disease-related processes. Early studies are mainly focused on inflammatory pathways involving the NFκB and the MAPK pathways. Nevertheless, many novel signalling pathways implicated in other cell processes, such as autophagy, have also recently been found to be activated upon RAGE stimulation and contribute to the detrimental effects of RAGE. In this review, we aim to provide a comprehensive summary of previous and recent studies relating to the complex molecular network of RAGE signalling, with a particular emphasis on RAGE transgenic mouse models. [Copyright &y& Elsevier]

Abstract: cAMP and mTOR signalling pathways control a number of critical cellular processes including metabolism, protein synthesis, proliferation and cell survival and therefore understanding the signalling events which integrate these two signalling pathways is of particular interest. In this study, we show that the pharmacological elevation of [cAMP]i in mouse embryonic fibroblasts (MEFs) and human embryonic kidney 293 (HEK293) cells inhibits mTORC1 activation via a PKA-dependent mechanism. Although the inhibitory effect of cAMP on mTOR could be mediated by impinging on signalling cascades (i.e. PKB, MAPK and AMPK) that inhibit TSC1/2, an upstream negative regulator of mTORC1, we show that cAMP inhibits mTORC1 in TSC2 knockout (TSC2−/−) MEFs. We also show that cAMP inhibits insulin and amino acid-stimulated mTORC1 activation independently of Rheb, Rag GTPases, TSC2, PKB, MAPK and AMPK, indicating that cAMP may act independently of known regulatory inputs into mTOR. Moreover, we show that the prolonged elevation in [cAMP]i can also inhibit mTORC2. We provide evidence that this cAMP-dependent inhibition of mTORC1/2 is caused by the dissociation of mTORC1 and 2 and a reduction in mTOR catalytic activity, as determined by its auto-phosphorylation on Ser2481. Taken together, these results provide an important insight into how cAMP signals to mTOR and down-regulates its activity, which may lead to the identification of novel drug targets to inhibit mTOR that could be used for the treatment and prevention of human diseases such as cancer. [Copyright &y& Elsevier]

Studies investigating whether there is a causative link between the gut microbiota and lifespan have largely been restricted to invertebrates or to mice with a reduced lifespan because of a genetic deficiency. We investigate the effect of early-life antibiotic exposure on otherwise healthy, normal chow-fed, wild-type mice, monitoring these mice for more than 700 days in comparison with untreated control mice. We demonstrate the emergence of two different low-diversity community types, post-antibiotic microbiota (PAM) I and PAM II, following antibiotic exposure. PAM II but not PAM I mice have impaired immunity, increased insulin resistance, and evidence of increased inflammaging in later life as well as a reduced lifespan. Our data suggest that differences in the composition of the gut microbiota following antibiotic exposure differentially affect host health and longevity in later life. [Display omitted] • Analysis of aged mice exposed to antibiotics in the pre-weaning period • Microbiota community type following antibiotics affects host health in later life • PAM II mice have increased insulin resistance, inflammaging, and reduced lifespan Lynn et al. expose mice to antibiotics in early life and then monitor these mice for more than 700 days. The study reveals that differences in the composition of the gut microbiota following antibiotic exposure differentially affects host immunity, metabolism, and longevity in later life. [ABSTRACT FROM AUTHOR]

Objective: To assess the performance of a hemolytic uremic syndrome (HUS) severity score among children with Shiga toxin-producing Escherichia coli (STEC) infections and HUS by stratifying them according to their risk of adverse events. The score has not been previously evaluated in a North American acute care setting.Study Design: We reviewed medical records of children <18 years old infected with STEC and treated in 1 of 38 participating emergency departments in North America between 2011 and 2015. The HUS severity score (hemoglobin [g/dL] plus 2-times serum creatinine [mg/dL]) was calculated using first available laboratory results. Children with scores >13 were designated as high-risk. We assessed score performance to predict severe adverse events (ie, dialysis, neurologic complication, respiratory failure, and death) using discrimination and net benefit (ie, threshold probability), with subgroup analyses by age and day-of-illness.Results: A total of 167 children had HUS, of whom 92.8% (155/167) had relevant data to calculate the score; 60.6% (94/155) experienced a severe adverse event. Discrimination was acceptable overall (area under the curve 0.71, 95% CI 0.63-0.79) and better among children <5 years old (area under the curve 0.77, 95% CI 0.68-0.87). For children <5 years, greatest net benefit was achieved for a threshold probability >26%.Conclusions: The HUS severity score was able to discriminate between high- and low-risk children <5 years old with STEC-associated HUS at a statistically acceptable level; however, it did not appear to provide clinical benefit at a meaningful risk threshold. [ABSTRACT FROM AUTHOR]

Objective: To characterize the pain experienced by children with acute gastroenteritis (AGE) in the 24 hours before emergency department (ED) presentation. Secondary objectives included characterizing ED pain, discharge recommendations, overall analgesic use, and factors that influenced analgesic use and pain severity.Study Design: A prospective cohort was recruited from 2 pediatric EDs (December 2014 to September 2017). Eligibility criteria included <18 years of age, AGE (≥3 episodes of diarrhea or vomiting in the previous 24 hours), and symptom duration <7 days at presentation.Results: We recruited 2136 patients, median age 20.8 months (IQR 10.4, 47.4) and 45.8% (979/2136) female. In the 24 hours before enrollment, most caregivers reported moderate (28.6% [610/2136, 95% CI 26.7-30.5]) or severe (46.2% [986/2136, CI 44.0-48.3]) pain for their child. In the ED, they reported moderate (31.1% [664/2136, 95% CI 29.1-33.1]) or severe ([26.7% [571/2136, 95% CI 24.9-28.7]) pain; analgesia was provided to 21.2% (452/2131). The most common analgesics used in the ED were acetaminophen and ibuprofen. At discharge, these were also most commonly recommended. Factors associated with greater analgesia use in the ED were high pain scores during the index visit, having a primary care physician, earlier presentation to emergency care, fewer diarrheal episodes, presence of fever, and hospitalization at index visit.Conclusions: Most caregivers of children presenting to the ED with AGE reported moderate or severe pain, both before and during their visit. Future research should focus on the development of effective, safe, and timely pain management plans. [ABSTRACT FROM AUTHOR]

Study Objective: We determine whether single-dose oral ondansetron administration to children with vomiting as a result of acute gastroenteritis without dehydration reduces administration of intravenous fluid rehydration.Methods: In this 2-hospital, double-blind, placebo-controlled, emergency department-based, randomized trial conducted in Karachi Pakistan, we recruited children aged 0.5 to 5.0 years, without dehydration, who had diarrhea and greater than or equal to 1 episode of vomiting within 4 hours of arrival. Patients were randomly assigned (1:1), through an Internet-based randomization service using a stratified variable-block randomization scheme, to single-dose oral ondansetron or placebo. The primary endpoint was intravenous rehydration (administration of ≥20 mL/kg of an isotonic fluid during 4 hours) within 72 hours of randomization.Results: Participant median age was 15 months (interquartile range 10 to 26) and 59.4% (372/626) were male patients. Intravenous rehydration use was 12.1% (38/314) and 11.9% (37/312) in the placebo and ondansetron groups, respectively (odds ratio 0.98; 95% confidence interval [CI] 0.60 to 1.61; difference 0.2%; 95% CI of the difference -4.9% to 5.4%). Bolus fluid administration occurred within 72 hours of randomization in 10.8% (34/314) and 10.3% (27/312) of children administered placebo and ondansetron, respectively (odds ratio 0.95; 95% CI 0.56 to 1.59). A multivariable regression model fitted with treatment group and adjusted for antiemetic administration, antibiotics, zinc prerandomization, and vomiting frequency prerandomization yielded similar results (odds ratio 0.91; 95% CI 0.55 to 1.53). There was no interaction between treatment group and age, greater than or equal to 3 stools in the preceding 24 hours, or greater than or equal to 3 vomiting episodes in the preceding 24 hours.Conclusion: Oral administration of a single dose of ondansetron did not result in a reduction in intravenous rehydration use. In children without dehydration, ondansetron does not improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Objective: To identify the gaps in the care of children infected with Shiga toxin-producing Escherichia coli (STEC), we sought to quantitate care received and management timelines. Such knowledge is crucial to the design of interventions to prevent the development of hemolytic uremic syndrome (HUS).Study Design: We conducted a retrospective case-series study of 78 children infected with STEC in Alberta, Canada, through the linkage of microbiology and laboratory results, telephone health advice records, hospital charts, physician billing submissions, and outpatient antimicrobial dispensing databases. Outcomes were the time intervals between initial presentation and reporting of positive culture result and symptom onset to HUS and to describe the proportions that had baseline blood work performed and received antibiotics.Results: Seventy-eight children infected with STEC were identified; 13% (10/78) developed HUS. Median time from initial presentation to laboratory stool sample receipt was 33 hours (IQR 18, 42); time to positive culture was 120 hours (IQR 86, 205). Time from symptom onset to HUS diagnosis was 188 ± 37 hours. Baseline blood tests were obtained in 74% (58/78) of infected children. Antibiotics were administered to 50% (5/10) of those who developed HUS and 22% (15/78) of those who did not; P = .11. The provincial telephone advice system received 31 calls regarding 24 children infected with STEC; 23% (7/31) of callers were recommended to seek emergency department care.Conclusions: A significant proportion of children developed HUS following multiple interactions with the health care system. Delays in the confirmation of STEC infection occurred. There are numerous opportunities to improve the timing, monitoring, and interventions in children infected with STEC. [ABSTRACT FROM AUTHOR]

Eukaryotic elongation factor 2 kinase (eEF2K) inhibits the elongation stage of protein synthesis by phosphorylating its only known substrate, eEF2. eEF2K is tightly regulated by nutrient-sensitive signalling pathways. For example, it is inhibited by signalling through mammalian target of rapamycin complex 1 (mTORC1). It is therefore activated under conditions of nutrient deficiency. Here we show that inhibiting eEF2K or knocking down its expression renders cancer cells sensitive to death under nutrient-starved conditions, and that this is rescued by compounds that block protein synthesis. This implies that eEF2K protects nutrient-deprived cells by inhibiting protein synthesis. Cells in which signalling through mTORC1 is highly active are very sensitive to nutrient withdrawal. Inhibiting mTORC1 protects them. Our data reveal that eEF2K makes a substantial contribution to the cytoprotective effect of mTORC1 inhibition. eEF2K is also reported to promote another potentially cytoprotective process, autophagy. We have used several approaches to test whether inhibition or loss of eEF2K affects autophagy under a variety of conditions. We find no evidence that eEF2K is involved in the activation of autophagy in the cell types we have studied. We conclude that eEF2K protects cancer cells against nutrient starvation by inhibiting protein synthesis rather than by activating autophagy. [ABSTRACT FROM AUTHOR]

Abstract The mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1 and MNK2) phosphorylate eukaryotic initiation factor 4E (eIF4E) and play important roles in promoting tumorigenesis and metabolic disease. Thus, inhibiting these enzymes might be valuable in the treatment of such conditions. We designed and synthesized a series of 4-((4-fluoro-2-isopropoxyphenyl)amino)-5-methylthieno[2,3- d ]pyrimidine derivatives, and evaluated their inhibitory activity against the MNKs. We found 15 compounds that were active as MNK inhibitors and that one in particular, designated MNK-7g , which was potent against MNK1 and substantially more potent against MNK2. The compound MNK-7g did not affect other signaling pathways tested and had no adverse effects on cell viability. As expected from earlier studies, MNK-7g also inhibited cell migration. Therefore, the compound MNK-7g , which forms an ionic bond with Asp226 in MNK2 and possesses a substituted aniline in a thieno[2,3-d] pyrimidine structure, is a promising starting point for the future development of novel drugs for treating or managing cancer and metabolic disease. Graphical abstract Image 1 Highlights • The MNK protein kinases (MNK1/2) play roles in cancer and metabolic disease. • From a set of 28 thienopyrimidines, 15 MNK inhibitors were identified. • One compound in particular, termed 7g, shows selectivity for MNK2 compared to MNK1. • Molecular docking revealed two H-bonds that are important for binding to MNKs. [ABSTRACT FROM AUTHOR]

• We studied 2462 children who had SARS-CoV-2 and transaminase testing performed. • Transaminase concentrations were elevated in 26% with isolated SARS-CoV-2 detection. • Isolated SARS-CoV-2 detection was not associated with elevated transaminases. • 90-day follow-up revealed no cases of new-onset liver disease. To evaluate the relationship between SARS-CoV-2 infection and liver injury by comparing transaminase concentrations among children tested for SARS-CoV-2 and other respiratory viruses in pediatric emergency departments. Eligible children were <18 years with suspected SARS-CoV-2, tested using molecular approaches in emergency departments between March 7, 2020, and June 15, 2021 (Pediatric Emergency Research Network), and between August 6, 2020, and February 22, 2022 (Pediatric Emergency Research Canada). We compared aspartate (AST) and alanine aminotransferase (ALT) concentrations at presentation for SARS-CoV-2 and other respiratory viruses through a multivariate linear regression model, with the natural log of serum transaminase concentrations as dependent variables. Of 16,892 enrolled children, 2,462 (14.6%) had transaminase concentrations measured; 4318 (25.6%) were SARS-CoV-2 positive, and 3932 (23.3%) were tested for additional respiratory viruses. Among study participants who had additional respiratory virus testing performed, the most frequently identified viruses were enterovirus/rhinovirus [8.7% (343/3,932)], respiratory syncytial virus [4.6% (181/3,932)], and adenovirus [2.6% (103/3,932)]. Transaminase concentrations were elevated in 25.6% (54/211) of children with isolated SARS-CoV-2 detection and 21.6% (117/541) of those with no virus isolated; P = 0.25. In the multivariable model, isolated SARS-CoV-2 detection was not associated with elevated ALT (adjusted geometric mean ratio (IU/L): 0.96; 95%Confidence Interval (CI): 0.84, 1.08) or AST (adjusted geometric mean ratio (IU/L): 1.03; 95%CI: 0.92, 1.16) concentrations, with negative respiratory panel as the referent group. Ninety-day follow-up was completed in 82.2% (3,550/4,318) of SARS-CoV-2 positive children; no cases of new-onset liver disease were reported. Among those tested, transaminase concentrations did not vary between SARS-CoV-2-positive children and those with a negative respiratory viral panel. In multivariate analysis, SARS-CoV-2 infection was not associated with increased initial transaminase concentrations compared to other respiratory viruses. [ABSTRACT FROM AUTHOR]

Alzheimer's disease is the most important cause of dementia but there is no therapy that has been demonstrated to stop or slow disease progression. Amyloid precursor protein (APP) is the source of amyloid-β (Aβ), which aggregates in Alzheimer's disease to form toxic oligomeric species. The endo-lysosomal system can clear APP and Aβ from the cell if these molecular species are trafficked through to the lysosome. Currently, there are no easy methods available for the analysis of lysosomal APP trafficking. We therefore generated a fusion protein (tandem-fluorescent, or tf-APP) that allows detection of changes in APP trafficking using accessible techniques such as flow cytometry. This permits rapid analysis or screening of genes and compounds that alter APP processing in the cell. Using our novel molecular probe, we determined that starvation induces trafficking of APP and APP-carboxy-terminal fragments (APP-CTFs) to the degradative endo-lysosomal network. In line with this finding, suppression of mTOR signalling using AZD8055 also strongly induced trafficking of APP to the endo-lysosomal system. Remarkably, activation of mTOR signalling via RHEB over-expression inhibited the starvation-induced autophagy but did not affect trafficking of tf-APP. These results show tf-APP can be used to determine how APP is trafficked through the lysosomal system of the cell. This molecular probe is therefore useful for determining the molecular mechanism behind the commitment of APP to the degradative pathway or for screening compounds that can induce this effect. This is important as clearance of APP and APP-CTF provides an important potential therapeutic strategy for Alzheimer's disease. [ABSTRACT FROM AUTHOR]