The perioperative immune response

PURPOSE OF REVIEW A host of immune modulators are now available in clinical practice. The perioperative period is characterized by profound alterations in host immunity, which can result in poor outcomes, which include infection, cancer recurrence and organ failure. Manipulation of the perioperative immune response has the potential to improve outcomes. A complete understanding of the mechanisms and clinical consequences of altered immune function in this setting is therefore imperative. RECENT FINDINGS Recent in-vivo data have emerged which further our understanding of the interaction between tissue damage, immune modulation and clinical outcomes by utilizing novel laboratory techniques capable of monitoring single-cell immune signatures. Traditional gene expression assays have continued to demonstrate their utility and have been instrumental in defining the host response to perioperative allogeneic blood transfusion. These mechanistic studies are complemented by large clinical studies describing associations between anaesthetic modalities and immune-related outcomes. SUMMARY Laboratory techniques are now available that can monitor the perioperative immune response and could be further developed to introduce personalized care pathways. Consideration must also be given to anaesthesia techniques and perioperative treatments that, although not immediately harmful, may be associated with poor outcomes temporally distant from the treatment, secondary to induced immunosuppression

Theory of short-range magnetic order for the t-J model

We present a self-consistent theory of magnetic short-range order based on a spin-rotation-invariant slave-boson representation of the 2D t-J model. In the functional-integral scheme, at the nearest-neighbour pair-approximation level, the bosonized t-J Lagrangian is transformed to a classical Heisenberg model with an effective (doping-dependent) exchange interaction which takes into account the interrelation of ``itinerant'' and ``localized'' magnetic behaviour. Evaluating the theory in the saddle-point approximation, we find a suppression of antiferromagnetic and incommensurate spiral long-range-ordered phases in the favour of a paramagnetic phase with pronounced antiferromagnetic short-range correlations.Comment: 2 pages, 1 Postscript figure, LTpaper.sty, Proc. XXI Int. Conf. on Low Temp. Phys. Prague 9

Theory of Magnetic Short--Range Order for High-T_c Superconductors

A theory of magnetic short--range order for high--$T_c$ cuprates is presented on the basis of the one--band $t$--$t^{\prime}$--Hubbard model combining the four--field slave--boson functional integral technique with the Bethe cluster method. The ground--state phase diagram evaluated self--consistently at the saddle--point and pair--approximation levels shows the experimentally observed suppression of magnetic long--range order in the favour of a paraphase with antiferromagnetic short--range order. In this phase the uniform static spin susceptibility consists of interrelated itinerant and local parts and increases upon doping up to the transition to the Pauli paraphase. Using realistic values of the Hubbard interaction we obtain the cusp position and the doping dependence of the zero--temperature susceptibility in reasonable agreement with experiments on $\rm La_{2-\delta}Sr_{\delta}CuO_4$.Comment: 3 pages, 2 Postscript figure, Proc. Int. Conf. SCES Zuerich Switzerland Aug. 96, to appear in Physica

Onset of Convection in a Permeable Medium Between Vertical Coaxial Cylinders

The onset of natural convection is examined for a fluid-saturated permeable medium contained between vertical coaxial cylinders of inner and outer radii r*i and r*0. The annular space is of height h*. The horizontal boundaries are isothermal, with heating from below and cooling from above. Both permeable and impermeable upper boundaries are considered. Critical Rayleigh numbers Rac and the preferred convective modes are determined as functons of the geometric ratios h*/r*i and r*0/r*i. The confining vertical walls of the annular space tend to increase Rac above the value for an infinite horizontal layer. The preferred modes are predominantly asymmetric

On the Stability and Flow Reversal of an Asymmetrically Heated Open Convection Loop

Experimental results are reported for a U-shaped, free convection loop. The top of the loop is open to an isothermal reservoir. The horizontal leg and one vertical leg are heated at rates Q1 and Q2, respectively. The loop is filled either with water or a watersaturated porous medium. Symmetric heating and asymmetric heating favouring the ascending leg of the loop both yield stable flows. Asymmetric heating favouring the descending leg leads to stable flows when the ratio Q1/Q2 is above a critical value. Below this critical value, the flow is observed to oscillate with increasing amplitude until the direction of flow in the loop undergoes a reversal. A steady flow follows the reversal. Analytical results include a stability analysis and time-dependent, one-dimensional numerical calculations, both of which compare favourably with experiment

Unusual features of pomoviral RNA movement

This work is partially supported by the Scottish Government’s Rural and Environment Science and Analytical Services (RESAS) DivisionPotato mop-top pomovirus (PMTV) is one of a few viruses that can move systemically in plants in the absence of the capsid protein (CP). Pomoviruses encode the triple gene block genetic module of movement proteins (TGB 1, 2, and 3) and recent research suggests that PMTV RNA is transported either as ribonucleoprotein (RNP) complexes containing TGB1 or encapsidated in virions containing TGB1. Furthermore, there are different requirements for local or systemic (long-distance) movement. Research suggests that nucleolar passage of TGB1 may be important for the long-distance movement of both RNP and virions. Moreover, and uniquely, the long-distance movement of the CP-encoding RNA requires expression of both major and minor CP subunits and is inhibited when only the major CP sub unit is expressed. This paper reviews pomovirus research and presents a current model for RNA movement.Publisher PDFPeer reviewe

Post-operative immune suppression is reversible with interferon gamma and independent of IL-6 pathways

Introduction The post-operative period is characterised by increased IL-6 production and clinical features of immune suppression. In vitro anti-inflammatory actions of IL-6 are mediated through suppression of interferon gamma (IFNγ) [1]. The clinical significance of IL-6 in mediating post-operative immune suppression remains unclear. Objectives To evaluate the role of IL-6 pathways in post-operative immune suppression and the reversibility of this phenomenon. Methods Patients over 45 years old undergoing elective surgery involving the gastrointestinal tract and requiring at least an overnight hospital stay were recruited. The primary outcome was hospital-acquired infection. IL-6 and IFNγ levels were assayed using ELISA preoperatively and at 24 and 48 hours. Pooled healthy control peripheral blood mononuclear cells (PBMCs) were cultured in perioperative serum and CD14+HLA-DR (mHLA-DR) geometric mean florescent intensity (MFI) measured in the presence and absence of interferon gamma (IFNγ) and IL-6 neutralising antibody. Data were analysed with non-parametric statistics. Results 119 patients were recruited and 44 (37%) developed a post-operative infection a median of 9 (IQR 5-11) days postoperatively (Figure 1). IL-6 levels increased from baseline to 24 hours postoperatively (P < 0.0001, Figure 1A) but were then unchanged between 24 and 48 hours (P = 0.06, Figure 1B). Postoperative IL-6 levels correlated with the duration of the procedure (P = 0.009). Higher preoperative IL-6 levels were observed in patients with cancer (P = 0.02). IL-6 levels at 24 (P = 0.0002) and 48 hours (P = 0.003) were associated with the later occurrence of infectious complications. This pattern remained similar after adjustment for baseline characteristics. Healthy donor PBMCs incubated with postoperative serum downregulated mHLA-DR MFI when compared with serum from baseline (n = 8, p = 0.008). Culturing in the presence of IFNγ 250IU (n = 4) prevented this decrease whereas culturing in the presence of IL-6 neutralising antibody 15ng/ml (n = 8) did not. Conclusions IL-6 levels increase following major surgery and are associated with an increased susceptibility to post-operative infections. Serum obtained from post-operative patients induces an immunosuppressive response through an IL-6 independent pathways which is reversible with IFNγ treatment

Oaths and Swearing in Ancient Greece

The oath was an institution of fundamental importance across a wide range of social interactions throughout the ancient Greek world, making a crucial contribution to social stability and harmony; yet there has been no comprehensive, dedicated scholarly study of the subject for over a century. This volume of a two-volume study explores the nature of oaths as Greeks perceived it, the ways in which they were used (and sometimes abused) in Greek life and literature, and their inherent binding power