Randomized trial examining cerebral haemodynamics following artificial or animal surfactant

To determine the effects of animal and artificial surfactants on cerebral haemodynamics, 20 premature babies receiving mechanical ventilation were randomized to receive Curosurf or Exosurf surfactant. Anterior cerebral artery blood flow velocity (CABFV) was measured using Doppler ultrasound before and up to 2 h after treatment. Following animal surfactant there was a rapid reduction in CABFV (median -36%, range -43% to +8%, p < 0:01), whereas artificial surfactant resulted in a slower rise which was less marked (median +20%, range -7% to +62%, p < 0:05). There were no significant changes in blood pressure. Two hours after administration, the oxygenation index (OI) improved significantly only in babies receiving animal surfactant. In this group there was a significant association between the change in CABFV at 1 min and the change in OI at 2 h ( r = 0:66, p < 0:05). Animal surfactant produces rapid improvements in ventilation which are associated with marked alterations in cerebral haemodynamics.     

Atrioesophageal Fistula After Cryoballoon Pulmonary Vein Isolation

Atrioesophageal Fistula After Cryoballoon PV Isolation . The risk of atrioesophageal fistula after cryoballoon pulmonary vein isolation is thought to be much lower than after radiofrequency ablation, seeing that no data exist on this complication so far. We report for the first time on the occurrence of an atrioesophageal fistula 4 weeks after cryoballoon ablation at the site of the left inferior pulmonary vein. We suggest that even when using cryothermal ablation technique, an imaging modality to assess the proximity of esophagus and left atrium should be routinely performed to avoid this fatal complication. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1254–1257, November 2012)     

Alpha-particle Irradiation of Haemopoietic Tissue in Pre- and Postnatal Mice

Summary

Pregnant mice (at 13 days gestation) and age-matched controls were injected with 30 kBq ²³⁹Pu/kg and the distribution of plutonium in maternal and foetal tissues measured. Approximately 2% of the activity injected into the mother reached each foetus in 24 h, 95% of which was contained in membranes and placenta. The concentration of plutonium in foetal liver was 3 times the average foetal body concentration; both liver and body concentrations in the foetus increased by the end of gestation. Each pup accumulated only 0.01% extra injected activity after 9 days lactation and, as the resulting concentrations in the neonatal skeletion were low, we conclude that the greatest haemopoietic risk to the offspring from mid-term contamination in utero is in the foetal liver (which received an average dose of 10–14 mGy between the time of mid-term contamination and birth). By the end of gestation about one-quarter of the original activity was transferred to foetal tissues from the maternal liver and skeleton. No significant changes in maternal distribution were detected as a result of lactation. The results of this study are discussed, along with a compilation of previously published data.     

Involvement of dendritic cells in long-term aortocoronary saphenous vein bypass graft failure.

Antigen-presenting dendritic cells are present in atherosclerotic lesions in human arterial intima, but have not been investigated in atherosclerotic and hyperplastic stenotic lesions that affect vein grafts used as arterial conduits. This study was undertaken to examine whether dendritic cells are present in aortocoronary artery saphenous vein bypass grafts affected by high-grade atheromatous stenosis. Stenotic saphenous vein coronary artery bypass grafts (angiographic luminal stenosis > 75%) were harvested from 10 patients (nine male, one female), aged 4271 years (mean 56.5) at re-do operation. The mean time interval from bypass surgery to the excision of stenotic grafts was 11.5 years (range 2-21). The specimens were fixed in 10% buffered formalin, embedded in paraffin blocks and the sections stained with antibodies to S-100 (to identify dendritic cells), CD3 (T cells), CD68 (macrophages), von Willebrand factor (endothelial cells) and alpha-smooth muscle actin (smooth muscle cells) using avidin-biotin complex immunoperoxidase technique. Normal veins were obtained during saphenous vein femoro-popliteal grafting. The stenotic venous grafts showed histological features typical of extensive arterialization, intimal hyperplasia, atherosclerotic plaque-like lesions, calcification and thrombosis. In areas of intimal hyperplasia, S-10O-positive cells were distributed irregularly among smooth muscle cells. S-100-positive dendritic cells were seen most frequently within atherosclerotic plaque-like lesions where they co-localized with CD3+ cells and CD68+ cells. S-100-positive dendritic cells were also seen accumulating within calcific foci. No S-100-positve cells were found in normal, ungrafted saphenous veins. We conclude that dendritic cells are present in aortocoronary saphenous vein bypass grafts affected by high grade stenosis. Dendritic cells are probably involved in immune mechanisms of atherogenesis through their interactions with T cells and macrophages. The accumulation of dendritic cells within calcific foci suggests their contribution to the calcification of stenotic venous grafts.     

Graduated compression stockings (20-30 mmHg) do not compress leg veins in the standing position

BACKGROUND: Since graduated compression stockings (GCS) reduce the risk of deep venous thrombosis (DVT) in both hospital and ambulant patients, we checked the compressive efficiency of 20-30 mmHg GCS in the standing position. METHODS: In 30 volunteers (17 normal legs, 13 varicose legs), duplex ultrasound was used to measure the internal diameters of the long saphenous vein, posterior tibial veins, peroneal veins, and soleal veins in the lying and standing position and with and without 20-30 mmHg GCS. RESULTS: Graduated compression stockings effectively compressed both superficial and deep veins in supine individuals but not the superficial or the deep veins when standing. In the varicose leg, the stockings did not compress the long saphenous vein at the mid-calf level even when supine. In the varicose leg the long saphenous vein was constricted at the upper band of the stocking, which might explain why superficial venous thrombosis is more common when compression stockings are worn. CONCLUSIONS: In the standing position, GCS did not compress the deep or superficial veins of the calf.