Indomethacin reversal of ethanol-induced suppression of ovine fetal breathing movements and relationship to prostaglandin E2

The effects of indomethacin on the ethanol-induced suppression of fetal breathing movements and fetal arterial plasma and cerebrospinal fluid (CSF) PGE2 concentrations and maternal arterial plasma PGE2 concentration were determined in the near-term fetal lamb. Eight conscious instrumented pregnant ewes (between 130 and 133 days of gestation; term, 147 days) received 1-h maternal intravenous infusion of 1 g ethanol/kg total body weight, and the fetus received 6-h intravenous infusion of indomethacin (1 mg/h per kg fetal body weight) commencing 30 min later. Serial fetal and maternal arterial blood samples (n = 8) and fetal CSF samples (n = 5) were collected at selected times throughout the 12-h study for the determination of PGE2 concentration. Fetal breathing movements were monitored continuously throughout the experimental period. Maternal ethanol infusion resulted in initial suppression (P less than 0.05) of fetal breathing movements for 2 h below pretreatment value, followed by a rapid increase in the incidence of fetal breathing movements after the onset of fetal indomethacin treatment. Fetal and maternal plasma PGE2 concentrations and fetal CSF PGE2 concentration were increased (P less than 0.05) above the pre-infusion value during the administration of ethanol and 1 h thereafter. Fetal indomethacin treatment suppressed (P less than 0.05) to undetectable levels fetal plasma and CSF PGE2 concentrations, which then became similar (P greater than 0.05) to pretreatment by 12 h. There was a positive correlation between fetal plasma and CSF PGE2 concentrations. There was an inverse correlation between the incidence of fetal breathing movements and fetal CSF PGE2 concentration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Review: Helicobacter pylori in pediatrics

Despite a decrease in the prevalence of Helicobacter pylori infection, it still poses a significant health burden worldwide. This review summarizes important pediatric studies on H pylori published from April 2018 to March 2019. Epidemiologic studies have reported different prevalences in different parts of the world and have mainly confirmed traditional risk factors. Several studies on pathophysiology attempted to identify risk markers in childhood for gastric cancer development later in life. One of the most interesting studies evaluated the relationship between eosinophilic esophagitis and H pylori infection; however, an inverse relationship was not confirmed. The high resistance of H pylori and, consequently, low eradication rates, is still a major concern and susceptibility testing before treatment has again been highlighted. Potassium‐competitive acid blockers are promising new acid‐suppressant drugs but their role in H pylori eradication schemes is still to be determined.     

Comparing a bioenergetics model with feeding rates of caged European starlings

We tested a bioenergetics model integrated within a mortality model that estimates numbers of European starlings (Sturnus vulgaris) poisoned with the avicide, Compound DRC-1339 Concentrate. The bioenergetics model predicted daily metabolic rate. Accuracy and reliability of this variable is critical because other algorithms (e.g., toxicity regressions, feeding behavior) in the mortality model depend on metabolic rate to calculate the amount of DRC-1339 ingested per bird. We tested the bioenergetics model by comparing its estimates of metabolic rate with those generated from measuring feeding rates of caged starlings during a feeding trial conducted outdoors during January 2008. Over the 12-day feeding trial, daily feeding rates of caged starlings indicated that metabolic rates ranged from 157 kJ/bird per day to 305 kJ/bird per day. The bioenergetics model predicted metabolic rates ranging from 208 kJ/bird per day to 274 kJ/bird per day. There was no difference between these 2 independently derived estimates of daily metabolic rate (paired t-test: t₍₁₁₎ = 1.4, P = 0.18). Using 95% confidence intervals calculated from variation of feeding rates among cages (n = 4, 6 birds/cage), the bioenergetics model's estimates were within 95% confidence intervals on 9 of 12 days and greater than the upper 95% confidence interval on 3 days. Daily estimates of metabolic rate were directly correlated between the bioenergetics model and the feeding-rate model (r₁₂ = 0.57, P = 0.05). A broad range of temperatures (−17°C to 14°C), wind speeds (0–40 km/hr), and percent cloud cover (0–100%) were encountered during the feeding trial. The bioenergetics model's predictions appeared robust to varying meteorological conditions typical of winters in middle latitudes of the interior United States. Compound DRC-1339 Concentrate is used by USDA Wildlife Services to manage chronic infestations of starlings at livestock facilities, which occur mainly during fall and winter. Compared to other methods used for estimating DRC-1339 mortality (e.g., counting birds pre- and posttreatment), bioenergetics modeling should improve the mortality model's overall accuracy and precision. © The Wildlife Society, 2011     

Chemical changes in the photoreceptor outer segments due to iron induced oxidative stress: analysis by Fourier transform infrared (FT-IR) microspectroscopy.

Oxidative stress is thought to be an important pathogenic mechanism in many diseases of the retina. The purpose of this study was to investigate the chemical changes that are present in the photoreceptor outer segments of the retina following exposure to oxidative stress. Fourier transform infrared (FT-IR) microspectroscopy enables the characterization and semi-quantitation of chemical functional groups in microscopic regions of tissue sections. This technique was used to evaluate the chemical changes in the outer segments following exposure to ferrous sulfate, which promotes oxidative tissue damage. A reduction of C=C-H and C=O functional groups was observed in the outer segments of iron-injected eyes compared to vehicle-injected eyes at 3 days following injection, which is prior to major histological changes that occur by 7 days. These functional groups are found in docosahexaenoic acid (DHA), which is present at a high concentration in the outer segments. DHA contains a series of six cis-conjugated double bonds, which are vulnerable to free radical attack, and the reduction of these unsaturation group absorptions suggests that DHA was degraded and/or removed from the outer segments. An unexpected finding was that several other chemical functional groups increased in concentration over time in the outer segments of vehicle-injected eyes compared to non-injected eyes. These increases generally did not include C=C-H or C=O, which suggests that either DHA was being degraded while other organic molecules were being concentrated, or that production of DHA failed to be upregulated in vehicle-injected eyes. In summary, there was a loss of both C=C-H and C=O functional group concentrations in the outer segments of iron-injected eyes, and there was an increased concentration of several other chemical functional groups following trauma induced by vehicle injection.     

Degradation of Granular Starch by the Bacterium Microbacterium aurum Strain B8.A Involves a Modular α-Amylase Enzyme System with FNIII and CBM25 Domains

The bacterium Microbacterium aurum strain B8.A, originally isolated from a potato plant wastewater facility, is able to degrade different types of starch granules. Here we report the characterization of an unusually large, multidomain M. aurum B8.A α-amylase enzyme (MaAmyA). MaAmyA is a 1,417-amino-acid (aa) protein with a predicted molecular mass of 148 kDa. Sequence analysis of MaAmyA showed that its catalytic core is a family GH13_32 α-amylase with the typical ABC domain structure, followed by a fibronectin (FNIII) domain, two carbohydrate binding modules (CBM25), and another three FNIII domains. Recombinant expression and purification yielded an enzyme with the ability to degrade wheat and potato starch granules by introducing pores. Characterization of various truncated mutants of MaAmyA revealed a direct relationship between the presence of CBM25 domains and the ability of MaAmyA to form pores in starch granules, while the FNIII domains most likely function as stable linkers. At the C terminus, MaAmyA carries a 300-aa domain which is uniquely associated with large multidomain amylases; its function remains to be elucidated. We concluded that M. aurum B8.A employs a multidomain enzyme system to initiate degradation of starch granules via pore formation.