While endothelial oxidant generation and subsequent leukocyte chemotaxis and activation are important mechanisms of tissue damage in ischemic organs, it is not known if oxidant generation may be involved in triggering the subsequent leukocyte-mediated injury which occurs. Questions remain whether particular oxidants and oxygen-free radicals are capable of modulating the expression of leukocyte adhesion molecules and effecting leukocyte endothelial adhesion. Studies were performed to determine the effect of different biologically occurring oxidant molecules and oxygen free radicals including: .O2-, .OH, and H2O2 on the expression of integrin and selectin adhesion molecules on the surface of human PMNs and to determine the effect of these alterations on PMN adhesion to the endothelium. Adhesion molecule expression on the surface of human PMNs was measured by immunofluorescence flow cytometry. Electron paramagnetic resonance spectroscopy was applied to characterize the presence of exogenous free radical generation as well as that from activated PMNs. It was observed that these oxidants can cause up-regulation of CD11b and CD18 expression with shedding of L-selectin. The kinetics and dose-response of these effects were analyzed and their functional significance determined by measuring PMN adhesion to cultured human aortic endothelial monolayers. These studies demonstrate that oxygen free radicals and non-radical oxidants can directly trigger PMN activation and adhesion to vascular endothelium.

Morphological and contractile characteristics of individual myocytes isolated from rats of 2, 6-9, and 24-25 mo of age were measured. The average myocyte length measured under high power light microscopy in unattached cells increased from 133 microns at 2 mo to 146 microns at 6-9 mo to 162 microns at 24-25 mo of age. The average slack sarcomere length was 1.85, 1.83, and 1.82 microns at 2, 6-9, and 24-25 mo, respectively. The average cell volume measured via Coulter counter techniques approximately doubled between 2 and 24 mo. During the electrically stimulated twitch in individual unloaded myocytes contracting from slack length the absolute amplitude of cell shortening increased with age, but when expressed relative to cell length or as sarcomere shortening the age effect was obliterated. Neither the maximal velocity of myocyte shortening (cell length/s) nor the calculated maximal sarcomere shortening velocity varied with age. The time course of the twitch increased with aging, due largely to an increase in the time to peak shortening. Thus aging is associated with an increase in cell size due to the addition of sarcomeres. Except for a prolonged time course, the twitch contraction characteristics normalized for cell length and sarcomere number in unloaded ventricular myocytes contracting over a range of sarcomere lengths below the slack length do not change appreciably with age.

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This retrospective study on a large cohort of patients shows that single transseptal puncture for positioning two or more catheters in the left atrium for AF ablation is a highly successful and safe maneuver with a very low morbidity in the majority of patients. This may avoid potential complications related to a second transseptal puncture.

Delirium is a common complication in elderly CICU patients, and is associated with a longer and more complicated hospital stay and increased short and long-term mortality. Our findings suggest the usefulness of a protocol for the early identification of delirium in the CICU. Clinicaltrials.gov: NCT02004665.