Role of group II and group III metabotropic glutamate receptors in spinal cord injury.

Spinal cord injury (SCI) produces an increase in extracellular excitatory amino acid (EAA) concentrations that results in glutamate receptor-mediated excitotoxic events. An important class of these receptors is the metabotropic glutamate receptors (mGluRs). mGluRs can activate a number of intracellular pathways that increase neuronal excitability and modulate neurotransmission. Group I mGluRs are known to modulate EAA release and the development of chronic central pain (CCP) following SCI; however, the role of group II and III mGluRs remains unclear. To begin evaluating group II and III mGluRs in SCI, we administered the specific agonists for group II, APDC, or group III, L-AP4, by interspinal injection immediately following SCI. Contusion injury was produced at spinal segment T10 with a New York University impactor (12.5-mm drop, 10-g rod 2 mm in diameter) in 30 adult male Sprague-Dawley rats (175-200 g). Evoked and spontaneous behavioral measures of CCP, locomotor recovery, changes in mGluR expression, and amount of spared tissue were examined. Neither APDC nor L-AP4 affected locomotor recovery or the development of thermal hyperalgesia; however, L-AP4 and APDC attenuated changes in mechanical thresholds and changes in exploratory behavior indicative of CCP. APDC- and L-AP4-treated groups had higher expression levels of mGluR2/3 at the epicenter of injury on post contusion day 28; however, there was no difference in the amount of spared tissue between treatment groups. These results demonstrate that treatment with agonists to group II and III mGluRs following SCI affects mechanical responses, exploratory behavior, and mGluR2/3 expression without affecting the amount of tissue spared, suggesting that the level of mGluR expression after SCI may modulate nociceptive responses.     

IgM Anti-D as Auto-Antibody in a Case of ''Cold'' Auto-Immune Haemolytic Anaemia

A case is reported of an auto-immune haemolytic anaemia caused by IgM anti-D. This antibody, although active at 37 degrees C, gave stronger reactions at lower temperatures and appeared to activate complement. The auto-immune haemolytic anaemia was probably secondary to a non-Hodgkins lymphoma.     

Commutability of the CRM 470 C-reactive protein value in the Dade Behring N High Sensitivity CRP assay.

Certified Reference Material 470 (CRM 470) demonstrates commutability with both the manufacturer's calibrator and with dilutions of serum pools in the Dade Behring N High Sensitivity assay for C-reactive protein (CRP). Both regression and back calibration show similar nonlinearity for all materials, largely due to the method of calibration curve fitting used in this assay. Significant differences in values among the currently available commercial assays can be largely overcome by using appropriate calibration curve fitting and the recommended value transfer protocol, which includes a minimum of two assay runs on each of at least 3 separate days, with weight correction of all reconstitutions and dilutions. An initial weight-corrected dilution should be made each day because of the relatively high level of CRP in CRM 470. In our opinion, the degree of nonlinearity, imprecision, and differences in values in currently available assays renders the use of fixed clinical decision cut-points questionable for high-sensitivity CRP. An alternative approach is suggested.     

P07Reduction of Allogeneic Red Cell Transfusion using Autologous Blood Cell Salvage in Knee Arthroplasty

Recent Hospital Transfusion Committee (HTC) audit at the Royal Bournemouth Hospital (RBH) confirmed an allogeneic red cell transfusion rate of 20% for primary Total Knee Replacement (TKR). Current policy at RBH states that when blood stocks reach 67% of normal (amber alert) then surgery with a >20% likelihood of blood transfusion will be cancelled. At current transfusion rates this would include primary TKR. Recent studies have shown a reduction in allogeneic transfusion rates when autologous transfusion drains are utilized. The purpose of this study was to see whether the current rate of allogeneic transfusion could be reduced with the introduction of the CellTransTM Autologous Knee Drainage Blood Transfusion System (ABT) in TKR at RBH. Over a 3 month period all patients undergoing primary, bilateral or revision knee arthroplasty received an ABT. Demographic data was collected from the orthopaedic pre‐assessment clinic. Following surgery further data was collected relating to volume of blood loss into the drain, volume of autologous blood re‐transfused, units of allogeneic blood required and the transfusion trigger, postoperative haemoglobin levels, infection rates and length of stay in hospital. We then compared this data set with retrospective data. Of 170 patients undergoing knee arthroplasty 141 received the ABT. The data collected was compared retrospectively with 169 patients from the previous 3 month period. We demonstrated a reduction in transfusion rates of 13% for primary TKR, 42% for bilateral TKR and 57% for revision TKR with the use of the ABT. In addition we demonstrated a reduction in total allogeneic blood use (99 units to 26 units) and a reduction in mean length of stay in hospital (8.6 days to 7.5 days) with the ABT. Further analysis of the data collected showed a 46% reduction in the allogeneic transfusion rate and a reduction in total allogeneic blood usage (99 units to 9 units) of anaemic patients presenting for surgery. This study has demonstrated a dramatic reduction in allogeneic blood transfusion rates with the use of the CellTransTM Autologous Blood Transfusion System. We have also shown a reduction in length of stay in hospital. Prior to the study primary total knee replacement would have been cancelled during times of limited blood availability (amber alert). The use of the ABT is good for the patient in reducing the need for allogeneic blood, and in addition has demonstrated a significant cost saving due to the reduced blood usage and potential prevention of cancelled operation lists.     

Platelet adherence to cardiac and noncardiac endothelial cells in culture: lack of a prostacyclin effect

Cardiac tissues show a propensity to develop nonbacterial thrombotic endocarditis, a meshwork of platelets and fibrin. This lesion may cause a predisposition to subsequent colonization by circulating microorganisms, leading to infective endocarditis. We measured platelet adherence in vitro to cultured endothelial cells derived from the porcine aortic valve and ascending aorta. We found that valvular endothelial cells showed a twofold to threefold higher adherence than ascending aortic endothelial cells of chromium 51-labeled platelets in the presence of proteolytically active thrombin. This finding did not correlate with endothelial prostacyclin release: cardiac valve endothelial cells released more prostacyclin than did, ascending aortic cells, exogenous prostacyclin had no effect on thrombin-stimulated adherence, and aspirin inhibition of endothelial prostacyclin synthesis showed no effect on platelet adherence. Fixation of platelets abolished thrombin-stimulated adherence; fixation of endothelial cells had minimal effect. We suggest that these differences may contribute to the propensity of the cardiac valve to develop nonbacterial thrombotic endocarditis.     

Wrist ratio correlation with carpal tunnel syndrome in industry

Employees from a large midwestern automobile manufacturing plant completed a preemployment evaluation which included a personal and family history, physical examination, and wrist ratio determinations obtained by dividing the anteroposterior diameter by the mediolateral diameter of the wrist. Over a 3-year period, 80 of these employees who developed symptoms compatible with carpal tunnel syndrome within 4-12 months of employment were entered into the study and were evaluated with standard electrodiagnostic techniques. The symptoms included nocturnal hand pain, paresthesia and weak grasp. Thirty-nine of the 80 employees had wrist ratios equal to or greater than 0.70. Twenty-four percent of the employees with wrist ratios less than 0.70 had abnormal electrodiagnostic studies compared with 74% of employees with wrist ratios greater than or equal to 0.70. Regression analysis performed on the data revealed a significant positive correlation between distal median motor latency and wrist ratio (P = 0.001). The study suggests the practical value of wrist ratio determination in job placement.