BackgroundPercutaneous closure of patent ductus arteriosus (PDA) in term neonates is established, but data regarding outcomes in infants born very preterm (<32 weeks of gestation) are minimal, and no published criteria exist establishing a minimal weight of 4 kg as a suitable cutoff. We sought to analyze outcomes of percutaneous PDA occlusion in infants born very preterm and referred for PDA closure at weights <4 kg.Methods and ResultsRetrospective analysis (January 2005–January 2014) was done at a single pediatric center. Procedural successes and adverse events were recorded. Markers of respiratory status (need for mechanical ventilation) were determined, with comparisons made before and after catheterization. A total of 52 very preterm infants with a median procedural weight of 2.9 kg (range 1.2–3.9 kg) underwent attempted PDA closure. Twenty‐five percent (13/52) of infants were <2.5 kg. Successful device placement was achieved in 46/52 (88%) of infants. An adverse event occurred in 33% of cases, with an acute arterial injury the most common complication. We observed no association between weight at time of procedure and the risk of an adverse event. No deaths were attributable to the PDA closure. Compared to precatheterization trends, percutaneous PDA closure resulted in improved respiratory status, including less exposure to mechanical ventilation (mixed effects logistic model, P<0.01).ConclusionsAmong infants born very preterm, percutaneous PDA closure at weights <4 kg is generally safe and may improve respiratory health, but risk of arterial injury is noteworthy. Randomized clinical trials are needed to assess clinically relevant differences in outcomes following percutaneous PDA closure versus alternative (surgical ligation) management strategies.

The small-amplitude motions of a plane interface between two fluids stressed by an initially perpendicular electric field are investigated. The fluids are modeled as Ohmic conductors and the convection of the surface charge caused by the dynamic interplay of interfacial electric shear stresses and the viscous stresses is highlighted. The influence of viscosity on instability growth rates in the zero-shear stress limits of perfectly conducting and perfectly insulating interfaces is described and compared to cases involving electrical shear stresses. Detailed attention is given to the instability of an interface between fluids having electrical relaxation times long compared to times of interest. It is shown that, for many common liquids, even a slight amount of surface charge makes the interface unstable at a considerably lower voltage than would be expected from theories based on the dielectrophoretic limit of no interfacial free charge. Experiments, performed using high-frequency ac stresses, gradually increased dc fields, and abruptly applied dc fields, support the theoretical model. In the general case, the electric Hartmann number is identified as an index to the dominance of the electric shear stresses over the viscous shear stresses in determining the interfacial convection of free charge.

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Results of this meta-analysis suggest that enhanced placental transfusion (delayed umbilical cord clamping or umbilical cord milking) at birth provides better neonatal outcomes than does early cord clamping, most notably reductions in overall mortality, lower risk of intraventricular hemorrhage, and decreased blood transfusion incidence. The optimal umbilical cord clamping practice among neonates requiring immediate resuscitation remains uncertain.

Percutaneous PDA closure during infancy is feasible and associated with few catastrophic AEs; however, the limitations constrain the interpretability and generalizability of the current findings.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that affects prematurely born infants and appears to evolve in part from early inflammatory responses in the lung. The inflammatory responses have been associated with protein and lipid oxidation in tracheal aspirate fluids. The present study was designed to test the hypothesis that in the first week of life specific oxidations and/ or altered expressions of proteins would be observed in tracheal aspirate fluids in infants who would subsequently develop BPD. We obtained tracheal aspirate fluids on Days of life 1, 3, and 6 from infants born at < or = 29 wk gestation, incubated the fluids with 2,4-dinitrophenylhyrazine (DNPH), separated the proteins electrophoretically, and assessed DNPH reactivity by immunonblots. DNPH reactivity of a protein that was identified as Clara cell secretory protein (CCSP) was observed more consistently in tracheal aspirate fluids from infants who later developed BPD than from infants who did not develop BPD. Tracheal aspirate fluid levels of immunoreactive CCSP were also lower on Day of life 1 in infants who developed BPD than in those who did not develop BPD. Increased CCSP oxidation and decreased immunoreactive CCSP expression in infants who subsequently developed BPD suggest that Clara cell function and CCSP expression may be critical for normal bronchoalveolar fluid homeostasis and that maintaining CCSP expression and function may be useful goals for targeted therapies for inhibition of the development of BPD.

Abstract. Regulation of the biliary excretion of reduced glutathione (GSH) and glutathione disulfide (GSSG) and responses to selected model toxins were examined in male Sprague-Dawley rats. In control and phenobarbital-pretreated rats in which the intrahepatic concentration of GSH was modulated by the administration of diethyl maleate or acetaminophen, the biliary concentration of GSH was consistently lower than, but directly proportional to, the intrahepatic concentration of GSH. Furthermore, increments in bile flow produced by the infusion of sulfobromophthalein (BSP)-glutathione were associated with proportional increases in the biliary excretion of GSH, suggesting that GSH passes into bile passively along a concentration gradient. In contrast, GSSG appears to be secreted into bile against a steep concentration gradient. An increased hepatic production and biliary excretion of GSSG resulted from the administration of t-butyl hydroperoxide. Measurement ofbiliary GSSG and BSP during a constant infusion of the GSH adduct of BSP indicated that GSSG shares a common excretory mechanism with GSH adducts. Diquat, nitrofurantoin, and paraquat also markedly stimulated the biliary excretion of GSSG. On a molar basis, these compounds generated much more GSSG than a direct substrate for glutathione peroxidase such as t-butyl hydroperoxide, indicating that the compounds undergo redox-cycling with concomitant production of hydrogen peroxide. Aminopyrine (0.8 mmol/kg) also significantly increased biliary GSSG. This increase, however, was associated with a proportional increase in bile flow and in the biliary excretion of GSH such that the GSSG/GSH ratio in bile did not change. Acetaminophen and chloroform, two compounds generating electrophilic metabolites that deplete intrahepatic GSH, led to a progressive decrease in the biliary excretion of GSH and GSSG. Furosemide and dimethylnitrosamine, the electrophilic metabolites ofwhich do not deplete hepatic GSH, minimally altered biliary GSH and GSSG. Similarly, carbon tetrachloride and iproniazid, which yield organic radical metabolites that can peroxidize membrane lipids, did not increase the biliary excretion of GSSG. This finding indicates that membrane-bound lipid hydroperoxides may not be good substrates for glutathione peroxidases. The measurement of the biliary excretion of GSSG and of the GSSG/GSH ratio in bile is a sensitive index of oxidative stress in vivo and thus complements other in vivo parameters for the study of reactive intermediates of xenobiotics such as the determination of covalent binding, the formation of lipid hydroxy acids, and the depletion of intracellular GSH.

Diosbulbin B (DIOB), a furanoid, is a major constituent of herbal medicine Dioscorea bulbifera L. Exposure to DIOB caused liver injury in humans and experimental animals. The mechanisms of DIOB-induced hepatotoxicities remain unknown. The present study demonstrated that DIOB induced hepatotoxicities in a time- and dose-dependent manner in mice. H&E stained histopathologic image showed the occurrence of necrosis in the liver obtained from the mice treated with DIOB at dose of 200 mg/kg. Pretreatment with KTC protected the animals from hepatotoxicities and hepatic GSH depletion induced by DIOB, increased area under the concentration-time curve of blood DIOB, decreased urinary excretion of GSH conjugates derived from DIOB, and increased urinary excretion of parent drug. Pretreatment with BSO exacerbated DIOB-induced hepatotoxicities. In order to define the role of furan moiety in DIOB-induced liver toxicities, we replaced the furan of DIOB with a tetrahydrofuran group by chemical hydrogenation of the furan ring of DIOB. No liver injury was observed in the animals given the same doses of tetrahydro-DIOB. The furan moiety was essential for DIOB-induced hepatotoxicities. The results implicate the cis-enedial reactive metabolite of DIOB was responsible for the observed toxicities. The observed modest depletion of hepatic GSH in DIOB-treated animals suggests the actions of one or more reactive metabolites, and the hepatic injury observed could be due at least in part to reactions of these metabolites with crucial biomolecules. Cytochrome P450 3A enzymes are implicated in DIOB-induced hepatotoxicities by catalyzing the formation of the reactive metabolite of DIOB.