Randomised controlled trial assessing the impact of a nurse delivered,flow monitored protocol for optimisation of circulatory status after cardiac surgery

Objective To assess whether a nurse led, flow monitored protocol for optimising circulatory status in patients after cardiac surgery reduces complications and shortens stay in intensive care and hospital.Design Randomised controlled trial.Setting Intensive care unit and cardiothoracic unit of a university teaching hospital.Participants 174 patients who underwent cardiac surgery between April 2000 and January 2003.Interventions Patients were allocated to conventional haemodynamic management or to an algorithm guided by oesophageal Doppler flowmetry to maintain a stroke index above 35 ml/m².Results 26 control patients had postoperative complications (two deaths) compared with 17 (four deaths) protocol patients (P = 0.08). Duration of hospital stay in the protocol group was significantly reduced from a median of nine (interquartile range 7-12) days to seven (7-10) days (P = 0.02). The mean duration of hospital stay was reduced from 13.9 to 11.4 days, a saving in hospital bed days of 18% (95% confidence interval -12% to 47%). Usage of intensive care beds was reduced by 23% (-8% to 59%).Conclusion A nurse delivered protocol for optimising circulatory status in the early postoperative period after cardiac surgery may significantly shorten hospital stay.     

Selection of Specific Endophytic Bacterial Genotypes by Plants in Response to Soil Contamination

Plant-bacterial combinations can increase contaminant degradation in the rhizosphere, but the role played by indigenous root-associated bacteria during plant growth in contaminated soils is unclear. The purpose of this study was to determine if plants had the ability to selectively enhance the prevalence of endophytes containing pollutant catabolic genes in unrelated environments contaminated with different pollutants. At petroleum hydrocarbon contaminated sites, two genes encoding hydrocarbon degradation, alkane monooxygenase (alkB) and naphthalene dioxygenase (ndoB), were two and four times more prevalent in bacteria extracted from the root interior (endophytic) than from the bulk soil and sediment, respectively. In field sites contaminated with nitroaromatics, two genes encoding nitrotoluene degradation, 2-nitrotoluene reductase (ntdAa) and nitrotoluene monooxygenase (ntnM), were 7 to 14 times more prevalent in endophytic bacteria. The addition of petroleum to sediment doubled the prevalence of ndoB-positive endophytes in Scirpus pungens, indicating that the numbers of endophytes containing catabolic genotypes were dependent on the presence and concentration of contaminants. Similarly, the numbers of alkB- or ndoB-positive endophytes in Festuca arundinacea were correlated with the concentration of creosote in the soil but not with the numbers of alkB- or ndoB-positive bacteria in the bulk soil. Our results indicate that the enrichment of catabolic genotypes in the root interior is both plant and contaminant dependent.     

Evidence against a role for alkaline phosphatase in the dephosphorylation of plasma membrane proteins: Hypophosphatasia fibroblast study

A major impasse to understanding the physiologic role(s) of alkaline phosphatase (ALP) is uncertainty as to its natural substrates. Various in vitro studies have led other investigators to suggest that ALP functions as a plasma membrane phosphoprotein phosphatase, consistent with our demonstration of ecto-topography of ALP in a variety of cell types. Thus, we compared the phosphorylation of plasma membrane proteins from control fibroblasts to those from profoundly ALP-deficient fibroblasts of hypophosphatasia patients. Fibroblasts from 3 controls and 3 hypophosphatasia patients (ALP activity < 4% of control) were biosynthetically labeled with ³²P_i for 2 h. ³²P incorporation into total trichloracetic acid (TCA)-precipitable material was not significantly different in control and patient cells. Plasma membranes were prepared from these cells by hypotonic shock, solubilized, and subjected to two-dimensional (2-D) gel electrophoretic separation. Video densitometric analysis of silver-stained 2-D gels failed to reveal any consistent difference in the protein profile between patient vs. control fibroblasts (i.e., unique species, altered pls, or increased abundance). Autoradiography of individual 2-D gels demonstrated 63 plasma membrane phosphoproteins with molecular weights ranging from 15 to 152 kDa and predominantly acidic pls. Although several of these phosphoproteins appeared to have had donor-specific labeling, none was unique or especially abundant in the hypophosphatasia group. Thus, in ALP-deficient fibroblasts, normal incorporation of ³²P into total cellular protein and into all identifiable plasma membrane phosphoproteins indicates that ALP does not modulate the phosphorylation of plasma membrane proteins.     

Cytotoxic reactions of rainbow trout, Salmo gairdneri Richardson, macrophages for larvae of the eye fluke Diplostomum spathaceum (Digenea)

The killing ability of rainbrow trout macrophages for the infective larval stages of Diploslomum spathaceum , cercariae and diplostomules, was investigated. Isolated macrophages kill significant numbers of diplostomules at effector: target ratios of 150: 1 or greater. In vitro killing was not increased using antiserum-coated larvae or in vivo -activated macrophages individually, but when they were combined increased killed occurred. Diplostomules were capable of eliciting respiratory burst activity from macrophages in vitro , suggesting that reactive oxygen species may have a role to play in the killing mechanism. The importance of macrophage activation in the protection afforded by immunization against this parasite is discussed.