315 research outputs found

    Effects of an Invasive Plant, Chinese Tallow (Triadica sebifera), on Development and Survival of Anuran Larvae

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    Amphibians are considered one of the most threatened vertebrate groups. Although numerous studies have addressed the many causes of amphibian population decline, little is known about effects of invasive plants. Chinese tallow (Triadica sebifera) is an exotic deciduous tree that has invaded the southeastern United States. Amphibian larvae in environments invaded by T. sebifera may be impacted negatively as autumn leaf litter decomposes in natal areas. We compared effects of leaf litter decomposition from T. sebifera and two native tree species on survival and development of four species of anuran larvae from eastern Texas. Larvae from Pseudacris fouquettei, Lithobates (Rana) sphenocephalus, Hyla versicolor, and Incilius (Bufo) nebulifer were introduced into mesocosms containing leaf litter from one of the three tree species. Pseudacris fouquettei and L. sphenocephalus, species that breed earlier in the year, had lower survival within the T. sebifera pools. Pseudacris fouquettei were smaller in T. sebifera mesocosms compared with native tree mesocosms, whereas L. sphenocephalus were larger in T. sebifera mesocosms. Hyla versicolor showed significant developmental and morphological differences in T. sebifera mesocosms; however, survival was not significantly different among treatments. Leaf litter treatment did not affect survival or development in I. nebulifer. Our results suggest that breeding season may determine how each species survives and develops in an environment with T. sebifera leaf litter. Triadica sebifera leaf litter breaks down faster than native species; therefore, negative effects may be short lived but pose a greater threat to species that breed soon after leaffall

    Disrupted Maturation of the Microbiota and Metabolome among Extremely Preterm Infants with Postnatal Growth Failure

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    Growth failure during infancy is a major global problem that has adverse effects on long-term health and neurodevelopment. Preterm infants are disproportionately affected by growth failure and its effects. Herein we found that extremely preterm infants with postnatal growth failure have disrupted maturation of the intestinal microbiota, characterized by persistently low diversity, dominance of pathogenic bacteria within the Enterobacteriaceae family, and a paucity of strictly anaerobic taxa including Veillonella relative to infants with appropriate postnatal growth. Metabolomic profiling of infants with growth failure demonstrated elevated serum acylcarnitines, fatty acids, and other byproducts of lipolysis and fatty acid oxidation. Machine learning algorithms for normal maturation of the microbiota and metabolome among infants with appropriate growth revealed a pattern of delayed maturation of the microbiota and metabolome among infants with growth failure. Collectively, we identified novel microbial and metabolic features of growth failure in preterm infants and potentially modifiable targets for intervention

    Adenosine infusion increases plasma levels of VEGF in humans

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    BACKGROUND: Many in vitro studies have shown that adenosine (Ado) can induce vascular endothelial growth factor (VEGF) mRNA and protein expression and stimulate endothelial proliferation. In the present study, we seek to determine whether Ado can increase circulating levels of VEGF protein in the intact human. METHODS: Five outpatients 49.3 ± 6.7 years of age and weighing 88.2 ± 8.5 kg were selected. They were given a 6 min intravenous infusion of Ado (0.14 mg kg(-1 )min(-1)) in conjunction with sestamibi myocardial perfusion scans. Mean blood pressure (MBP, calculated from systolic and diastolic values) and heart rate (HR) were determined before Ado infusion and every 2 min for the next 10 min. Plasma VEGF concentrations (ELISA) were determined immediately before Ado infusion and 1 h, 2 h, and 8 h after the infusion. RESULTS: Plasma VEGF concentration averaged 20.3 ± 2.0 pg ml(-1 )prior to Ado infusion, and increased to 62.7 ± 18.1 pg ml(-1 )at 1 h post- infusion (p < 0.01). VEGF plasma concentration returned to basal levels 2 h after infusion (23.3 ± 3.4 pg ml(-1)). MBP averaged 116 ± 7 mmHg and heart rate averaged 70 ± 7 prior to Ado infusion. MBP decreased by a maximum of ~22% and HR increased by a maximum of ~17% during the infusion. CONCLUSION: We conclude from these preliminary findings that intravenous infusion of adenosine can increase plasma levels of VEGF in humans

    Delivery of drugs, proteins and genes into cells using transferrin as a ligand for receptor-mediated endocytosis

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    Transferrin, an iron-transporting serum glycoprotein, is efficiently taken up into cells by the process of receptor-mediated endocytosis. Transferrin receptors are found on the surface of most proliferating cells, in elevated numbers on erythroblasts and on many kinds of tumors. The efficient cellular mechanism for uptake of transferrin has been subverted for the delivery of low-molecular-weight drugs, protein toxins, and liposomes by linkage of these agents to transferrin or to anti-transferrin receptor antibodies. Linkage may be via chemical conjugation procedures or by the generation of chimeric fusion proteins. Transferrin conjugated to DNA-binding compounds (e.g. polycations or intercalating agents) has been successfully used for the import of DNA molecules into cells. High-level gene expression is obtained only if endosome-disruptive agents such as influenza hemagglutinin peptides or adenovirus particles are included which release the DNA complex from intracellular vesicles into the cytoplasm

    Spread, circulation, and evolution of the Middle East respiratory syndrome coronavirus

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    The Middle East respiratory syndrome coronavirus (MERS-CoV) was first documented in the Kingdom of Saudi Arabia (KSA) in 2012 and, to date, has been identified in 180 cases with 43% mortality. In this study, we have determined the MERS-CoV evolutionary rate, documented genetic variants of the virus and their distribution throughout the Arabian peninsula, and identified the genome positions under positive selection, important features for monitoring adaptation of MERS-CoV to human transmission and for identifying the source of infections. Respiratory samples from confirmed KSA MERS cases from May to September 2013 were subjected to whole-genome deep sequencing, and 32 complete or partial sequences (20 were ≥99% complete, 7 were 50 to 94% complete, and 5 were 27 to 50% complete) were obtained, bringing the total available MERS-CoV genomic sequences to 65. An evolutionary rate of 1.12 × 10−3 substitutions per site per year (95% credible interval [95% CI], 8.76 × 10−4; 1.37 × 10−3) was estimated, bringing the time to most recent common ancestor to March 2012 (95% CI, December 2011; June 2012). Only one MERS-CoV codon, spike 1020, located in a domain required for cell entry, is under strong positive selection. Four KSA MERS-CoV phylogenetic clades were found, with 3 clades apparently no longer contributing to current cases. The size of the population infected with MERS-CoV showed a gradual increase to June 2013, followed by a decline, possibly due to increased surveillance and infection control measures combined with a basic reproduction number (R0) for the virus that is less than 1

    Inhaled PGE1 in neonates with hypoxemic respiratory failure: two pilot feasibility randomized clinical trials.

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    BackgroundInhaled nitric oxide (INO), a selective pulmonary vasodilator, has revolutionized the treatment of neonatal hypoxemic respiratory failure (NHRF). However, there is lack of sustained improvement in 30 to 46% of infants. Aerosolized prostaglandins I2 (PGI2) and E1 (PGE1) have been reported to be effective selective pulmonary vasodilators. The objective of this study was to evaluate the feasibility of a randomized controlled trial (RCT) of inhaled PGE1 (IPGE1) in NHRF.MethodsTwo pilot multicenter phase II RCTs are included in this report. In the first pilot, late preterm and term neonates with NHRF, who had an oxygenation index (OI) of ≥15 and &lt;25 on two arterial blood gases and had not previously received INO, were randomly assigned to receive two doses of IPGE1 (300 and 150 ng/kg/min) or placebo. The primary outcome was the enrollment of 50 infants in six to nine months at 10 sites. The first pilot was halted after four months for failure to enroll a single infant. The most common cause for non-enrollment was prior initiation of INO. In a re-designed second pilot, co-administration of IPGE1 and INO was permitted. Infants with suboptimal response to INO received either aerosolized saline or IPGE1 at a low (150 ng/kg/min) or high dose (300 ng/kg/min) for a maximum duration of 72 hours. The primary outcome was the recruitment of an adequate number of patients (n = 50) in a nine-month-period, with fewer than 20% protocol violations.ResultsNo infants were enrolled in the first pilot. Seven patients were enrolled in the second pilot; three in the control, two in the low-dose IPGE1, and two in the high-dose IPGE1 groups. The study was halted for recruitment futility after approximately six months as enrollment targets were not met. No serious adverse events, one minor protocol deviation and one pharmacy protocol violation were reported.ConclusionsThese two pilot RCTs failed to recruit adequate eligible newborns with NHRF. Complex management RCTs of novel therapies for persistent pulmonary hypertension of the newborn (PPHN) may require novel study designs and a longer period of time from study approval to commencement of enrollment.Trial registrationCLINICALTRIALS.GOV: Pilot one: NCT number: 00598429 registered on 10 January 2008. Last updated: 3 February 2011. Pilot two: NCT number: 01467076 17 October 2011. Last updated: 13 February 2013

    Insulin, Hyperglycemia, and Severe Retinopathy of Prematurity in Extremely Low-Birth-Weight Infants

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    Objective This study aims to determine the association between hyperglycemia, insulin therapy, and severe retinopathy of prematurity (ROP) in extremely low-birth-weight (ELBW) infants. Study Design In this retrospective database study, we included all ELBW infants who were 180 mg/dL. Covariates were GA, small for GA status, discharge year, sex, Apgar score at 5 minutes, mechanical ventilation, oxygen use, bacteremia, and postnatal steroid exposure. We defined severe ROP as ROP requiring bevacizumab, cryotherapy, laser therapy, or vitrectomy. Sensitivity analysis using BG > 150 mg/dL and > 200 mg/dL was performed. Results A total of 24,548 infants were included; 2,547 (10%) had severe ROP. Hyperglycemia alone was not associated with severe ROP (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.66-1.17). Hyperglycemia and insulin use were not associated with severe ROP (OR, 1.43; 95% CI, 0.91-2.23). BG > 150 mg/dL and insulin use were associated with severe ROP (OR, 1.34; 95% CI, 1.02-1.76). Conclusions Hyperglycemia alone was not associated with severe ROP in ELBW infants. However, we did observe a possible trend between the use of insulin and severe ROP.National Center for Advancing Translational Sciences of the National Institutes of Health (NIH)U.S. governmentNational Institute of Child Health and Human DevelopmentNIHNational Center for Advancing Translational Sciences of the NIHU.S. Food and Drug AdministrationCempra PharmaceuticalsDuke Univ, Dept Pediat, Sch Med, Durham, NC 27706 USADuke Univ, Sch Med, Duke Clin Res Inst, Durham, NC USAKK Womens & Childrens Hosp, Childrens Intens Care Unit, Singapore, SingaporeUniv Fed Sao Paulo, Ecola Paulista Med, Div Neonatal Med, Sao Paulo, BrazilUniv N Carolina, Dept Pediat, Chapel Hill, NC USAMEDNAX Inc, Pediat Med Grp, Jacksonville, FL USAUniv Fed Sao Paulo, Ecola Paulista Med, Div Neonatal Med, Sao Paulo, BrazilNIH: UL1TR001117U.S. government: HHSN267200700051CNational Institute of Child Health and Human Development: K23HD068497National Institute of Child Health and Human Development: HHSN275201000003INational Institute of Child Health and Human Development: 1R01-HD081044-01National Center for Advancing Translational Sciences of the NIH: UL1TR001117U.S. Food and Drug Administration: 1R18-FD005292-01Cempra Pharmaceuticals: HHS0100201300009CWeb of Scienc
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