Identifying hypoxia in a newborn piglet model using urinary NMR metabolomic profiling.

Establishing the severity of hypoxic insult during the delivery of a neonate is key step in the determining the type of therapy administered. While successful therapy is present, current methods for assessing hypoxic injuries in the neonate are limited. Urine Nuclear Magnetic Resonance (NMR) metabolomics allows for the rapid non-invasive assessment of a multitude breakdown products of physiological processes. In a newborn piglet model of hypoxia, we used NMR spectroscopy to determine the levels of metabolites in urine samples, which were correlated with physiological measurements. Using PLS-DA analysis, we identified 13 urinary metabolites that differentiated hypoxic versus nonhypoxic animals (1-methylnicotinamide, 2-oxoglutarate, alanine, asparagine, betaine, citrate, creatine, fumarate, hippurate, lactate, N-acetylglycine, N-carbamoyl-β-alanine, and valine). Using this metabolomic profile, we then were able to blindly identify hypoxic animals correctly 84% of the time compared to nonhypoxic controls. This was better than using physiologic measures alone. Metabolomic profiling of urine has potential for identifying neonates that have undergone episodes of hypoxia

Virus-induced asthma attack: The importance of allergic inflammation in response to viral antigen in an animal model of asthma.

Asthma exacerbation can be a life-threatening condition, and is most often triggered by common respiratory viruses. Poor asthma control and worsening of respiratory function is associated with increased airway inflammation, including eosinophilia. Prevention of asthma exacerbation relies on treatment with corticosteroids, which preferentially inhibit allergic inflammation like eosinophils. Human studies demonstrate that inactivated virus can trigger eosinophil activation in vitro through antigen presentation and memory CD4+ lymphocytes. We hypothesized that animals with immunologic memory to a respiratory virus would also develop airway hyperresponsiveness in response to a UV-inactivated form of the virus if they have pre-existing allergic airway inflammation. Guinea pigs were ovalbumin-sensitized, infected with live parainfluenza virus (PIV), aerosol-challenged with ovalbumin, and then re-inoculated 60 days later with live or UV-inactivated PIV. Some animals were either treated with dexamethasone prior to the second viral exposure. Lymphocytes were isolated from parabronchial lymph nodes to confirm immunologic memory to the virus. Airway reactivity was measured and inflammation was assessed using bronchoalveolar lavage and lung histology. The induction of viral immunologic memory was confirmed in infected animals. Allergen sensitized and challenged animals developed airway hyperreactivity with eosinophilic airway inflammation when re-exposed to UV-inactivated PIV, while non-sensitized animals did not. Airway hyperreactivity in the sensitized animals was inhibited by pre-treatment with dexamethasone. We suggest that the response of allergic inflammation to virus antigen is a significant factor causing asthma exacerbation. We propose that this is one mechanism explaining how corticosteroids prevent virus-induced asthma attack

Average concentrations and inter-quartile ranges of urinary metabolites in hypoxia and sham treated newborn piglets used to generate the metabolomic model (in mmol of metabolite/mmol creatinine).

<p>IQ range = Q3-Q1.</p

Physiological effects of hypoxia in newborn piglets.

<p>Temporal changes in (A) oxygen saturation (% O₂), (B) blood pH, (C) mean arterial pressure (mmHg), and (D) cardiac output between hypoxia (n = 7) and sham (n = 6) treated animals. *P<0.05 Sham vs. Hypoxia for corresponding time point.</p

The metabolomic model of hypoxic vs. sham treated animals.

<p>PLS-DA analysis of urine from hypoxic versus sham treated animals was based on differences in metabolites between groups shown as the Coefficient of Variation (CoV) plot (A). The importance of each metabolite within the model is shown as the Variability of Importance (VIP) plot (B).</p

Invasive Amoebiasis: A Review of Entamoeba Infections Highlighted with Case Reports

Entamoeba histolytica infections of the gastrointestinal tract are common in the developing world but rare in North America. The authors present two cases: one involving an individual who had not travelled to an endemic area and another involving an individual who was born in Bulgaria. Both presented with severe abdominal pain and diarrhea. Endoscopic assessment revealed scattered colonic ulcerations and one patient was found to have a liver abscess on imaging. Stool ova and parasite studies were negative in both cases and both were diagnosed on review of colonic biopsies. On review of all Entamoeba cases in the Calgary Health Zone (Alberta), ova and parasite analysis found an average of 63.7 Entamoeba cases per year and a pathology database review revealed a total of seven cases of invasive E histolytica (2001 to 2011). Both patients responded well to antibiotic therapy. E histolytica should be considered in new-onset colitis, especially in individuals from endemic areas

Treatment with dexamethasone prior to secondary live virus infection prevents airway hyperreactivity only in sensitized animals.

<p>Some animals were treated with dexamethasone (i.p.) before the second live PIV infection. <b>(A)</b> Dexamethasone treatment of non-sensitized animals before secondary infection with PIV (n = 6) had no effect on bronchoconstriction in response to histamine (i.v.), compared to untreated animals (n = 5). In contrast, in OVA-sensitized animals, dexamethasone treatment (n = 3) significantly reduced bronchoconstriction responses (n = 4; p = 0.001). Sham inoculated controls were also included (n = 5 each). <b>(B)</b> Dexamethasone treatment before live PIV re-infection (white bars, n = 4, p<0.01) induced a significant decrease in total cell numbers compared to untreated and re-infected non-sensitized and sensitized animals (n = 6: p<0.01), but this did not reach statistical significance for individual cell counts. Error bars represent SEM.</p

Experimental timeline flowchart.

<p>Guinea pigs were sensitized to ovalbumin or given sham sensitizations via i.p. injections on Days 1 and 3. Sensitized and non-sensitized GPs were inoculated intranasally with parainfluenza virus (PIV) on Day 21. After recovery from virus or sham infection, all GPs were exposed to an aerosolized solution of ovalbumin on Day 45, with the exception of age-matched controls. Some GPs received dexamethasone on Days 61 to 65. Animals were inoculated intranasally with live-PIV, UV-PIV, or sham (NaCl 0.9%) on Day 70. On Day 75 all animals underwent airway hyperreactivity and inflammation assessment.</p

Inoculation with UV-inactivated virus induced airway hyperreactivity in only sensitized animals.

<p><b>(A)</b> Non-sensitized animals inoculated with UV-PIV (n = 5; p<0.001), had significantly lower bronchoconstriction in response to histamine (i.v.) compared to animals infected with live virus (n = 5). In contrast, sensitized animals inoculated with UV-inactivated virus (closed diamond, n = 8) showed high levels of bronchoconstriction in response to histamine (i.v.) similar to animals re-infected with live-PIV (n = 5). Sham inoculated controls were also included (open triangle, n = 5 each). <b>(B)</b> Non-sensitized animals inoculated with UV-PIV (n = 5) showed a significant increase in total cell numbers in the BAL compared to sham controls (n = 3; p = 0.05). Differences in individual cell types did not reach statistical significance. Sensitized animals inoculated with UV-PIV (n = 5; P<0.0001) showed significantly higher total cell numbers, with higher macrophage and eosinophil cell counts, compared to sham controls (n = 4; P<0.01 and P<0.01 respectively). Error bars represent SEM.</p