Background Among chickens, meat producing broiler strains are highly prone to develop severe pulmonary hypertension (PH) associated with endothelial dysfunction. However, pulmonary endothelial function appears to be unaffected during prenatal life.Objective To test the hypothesis that exposure to chronic prenatal hypoxia induces endothelial impairment and accelerates the development of PH in chickens prone to the disease.Methods Fertilized eggs from two genetic lines of broiler chickens differing in susceptibility to PH (high sensitivity: HS, low sensitivity: LS) were incubated under normoxic or hypoxic (15% O2) conditions from day 6 to day 19 of a 21-d incubation period. On day 19 isolated intrapulmonary artery segments were mounted in a myograph for isometric tension recording. The contractile responses induced by KCl as well as the relaxations induced by acethylcholine (ACh), the nitric oxide donor sodium nitroprusside (SNP), and the adenylate cyclase activator forskolin were tested.Results Hypoxia produced a reduction in the weight of the HS (31.1 Ϯ 0.6 g vs 27.3 Ϯ 0.6 g, PϽ0,001) and the LS (32.1Ϯ 0.6 vs 28.6 Ϯ 0.9 PϽ0,001) embryos. KCl-induced contraction was unaffected by hypoxia in both groups. Endothelium-dependent (induced by ACh) and -independent (induced by SNP and forskolin) relaxations were also unaffected by hypoxia in both groups. AChinduced relaxation was reduced by the NO synthase inhibitor L-NAME (10 mM) and abolished by the soluble guanylyl cyclase inhibitor ODQ (10 microM). L-NAME induced inhibition of ACh-induced relaxation was less marked in normoxic embryos of the HS group than in the other three groups.Conclusions Chronic hypoxia during incubation reduced embryonic growth but did not influence vascular reactivity in chicken embryos prone to postnatal pulmonary hypertension. INTESTINAL PERMEABILITY AND MECHANICAL VENTILATION IN PRE-TERM INFANTS CONCLUSIONS. IN CONTRAST TO OUR HYPOTHESIS, WE DID NOT FIND A HIGHER INTESTINAL PERMEABILITY IN MECHANICAL VENTILATED INFANTS COMPARED TO NON-VENTILATED INFANTS, MEASURED Ͻ48 H AFTER BIRTH. FURTHERMORE, WE DID NOT FIND A SMALLER DECREASE IN INTESTINAL PERMEABILITY IN THE FIRST WEEK OF LIFE IN VENTILATED INFANTS COMPARED TO NON-VENTILATED INFANTS. FURTHER STUDIES ARE NEEDED TO ELUCIDATE THE EFFECT OF MECHANICAL VENTILATION ON INTESTINAL PERMEABILITY IN PRETERM INFANTS. FOLLOW UP AFTER AABR NEONATAL HEARING SCREENING IN NICU GRADUATES.HLM VAN Goal To explore the severity and type of bilateral HL as wel as the prognostic value of the first diagnostic BERA.Methods NICU graduates with bilateral HL from one NICU (Zwolle) were included. Severity of HL was established as mild (20 -39dB), moderate (40 -59dB), severe (60 -90 dB) or profound (Ͼ90dB). Type of HL was conductive, perceptive, combined, or auditory neuropathy. Improvement of Ͼ 20 dB between the first BERA and observation audiometry at Ͼ 2 years at follow up was considered as clinically relevant.Results Severity of HL after first diagnostic BERA of 37 newborns with bilateral HL was 6 mild, 7 mo...
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