Mobility of the spine after spinal surgery in acute spinal cord injury

STUDY DESIGN

Retrospective study of mobility of the spine.

OBJECTIVES

To study the relation between mobility of the spine, operation and length of surgical stabilisation.

SETTING

The National Spinal Injuries Centre, Stoke Mandeville Hospital, Aylesbury, UK.

METHOD

Questionnaires were sent to 99 consecutive acute traumatic spinal cord-injured patients (UK residents) admitted in 1990-1994. All had acute spinal surgery. A total of 68 responded. Their replies, medical records and radiographs were reviewed.

RESULTS

(1) In all, 63 patients had surgery in the cervical, thoracolumbar or lumbar spine; 11 of them had more than two functional spinal units (FSUs) stabilised, 10 of these 11 (91%) had less than satisfactory results in terms of metal failure, improper placement of the implant or functional restriction of spinal mobility (FROSM). A total of 35 had 1-2 FSUs stabilised. None of them had metal failure or improper placement of implant, but 14 (40%) had less than satisfactory result due to FROSM; 17 had laminectomy alone, four of these had FROSM. (2) Five patients had surgery in the thoracic spine. Three of these who had 5-7 FSUs stabilised had no FROSM. Two had laminectomy alone, one of whom had FROSM.

CONCLUSION

(1) Long surgical stabilisation in the cervical, thoracolumbar and lumbar spines was likely to result in either metal failure or FROSM. (2) Long surgical stabilisation of the thoracic spine was not associated with either metal failure or FROSM. (3) A small proportion of patients had laminectomy alone. One of them who had multiple injuries had FROSM.

Interleukin 17 induces cartilage collagen breakdown: novel synergistic effects in combination with proinflammatory cytokines

OBJECTIVE

To investigate whether interleukin 17 (IL17), derived specifically from T cells, can promote type II collagen release from cartilage. The ability of IL17 to synergise with other proinflammatory mediators to induce collagen release from cartilage, and what effect anti-inflammatory agents had on this process, was also assessed.

METHODS

IL17 alone, or in combination with IL1, IL6, oncostatin M (OSM), or tumour necrosis factor alpha (TNFalpha), was added to bovine nasal cartilage explant cultures. Proteoglycan and collagen release were determined. Collagenolytic activity was determined by bioassay. Chondroprotective effects of IL4, IL13, transforming growth factor beta1 (TGFbeta1) and insulin-like growth factor-1 (IGF1) were assessed by inclusion in the explant cultures.

RESULTS

IL17 alone stimulated a dose dependent release of proteoglycan and type II collagen from bovine nasal cartilage explants. Suboptimal doses of IL17 synergised potently with TNFalpha, IL1, OSM, and IL6 to promote collagen degradation. This collagen release was completely inhibited by tissue inhibitor of metalloproteinase-1 and BB-94 (a synthetic metalloproteinase inhibitor), and was significantly reduced by IL4, IL13, TGFbeta1, and IGF1. In IL17 treated chondrocytes, mRNA expression for matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 was detected. Moreover, a synergistic induction of these MMPs was seen when IL17 was combined with other proinflammatory cytokines.

CONCLUSIONS

IL17 can, alone and synergistically in combination with other proinflammatory cytokines, promote chondrocyte mediated MMP dependent type II collagen release from cartilage. Because levels of all these proinflammatory cytokines are raised in rheumatoid synovial fluids, this study suggests that IL17 may act as a potent upstream mediator of cartilage collagen breakdown in inflammatory joint diseases.

Postural sway of subjects wearing the U.S. Army chemical protective ensemble after functional activity

BACKGROUND

This study assessed the effects of wearing the chemical protective clothing ensemble (CPE) vs. the battle dress uniform (BDU) on postural sway after 18 min of simulated field activity. Postural sway is a measure of static balance where a person maintains his/her center of gravity over his/her base of support by swaying fore to aft usually around the ankle joint axis.

HYPOTHESES

Subjects' postural sway would increase more post-exercise while wearing the CPE vs. the BDU. The increase in postural sway while wearing the CPE would be due to decreased visual and somatosensory inputs.

METHODS

Static balance was measured on 25 subjects pre- and post-exercise on the NeuroCom SMART Balance Master using the Sensory Organization Test protocol. Following a test-retest, repeated measures design, each subject completed the protocol twice, once while wearing only the BDU and once while wearing the CPE.

RESULTS

A 2 x 2 repeated measures, multivariate analysis of variance revealed no significant difference between the static balance of subjects wearing the CPE vs. wearing the BDU pre- or post-exercise.

CONCLUSIONS

The authors suggest that the wearing of the CPE does not affect static balance, even after completing 18 min of functional tasks. Future research should objectively quantify the amount of fatigue postexercise and employ a protocol that has been previously shown to increase postural sway.

The effects of pulsatile versus nonpulsatile perfusion on blood viscoelasticity before and after deep hypothermic circulatory arrest in a neonatal piglet model

Blood trauma increases blood viscoelasticity by increasing red cell aggregation and plasma viscosity and by decreasing cell deformability. During extracorporeal circulation, the mode of perfusion (pulsatile or nonpulsatile) may have a significant impact on blood trauma. In this study, a hydraulically driven dual chamber pulsatile pump system was compared to a standard nonpulsatile roller pump in terms of changes in the blood viscosity and elasticity during cardiopulmonary bypass (CPB) and pre and post deep hypothermic circulatory arrest (DHCA). Piglets, with an average weight of 3 kg, were used in the pulsatile (n = 5) or nonpulsatile group (n = 5). All animals were subjected to 25 min of hypothermia, 60 min of DHCA, 10 min of cold reperfusion, and 40 min of rewarming with a pump flow of 150 ml/kg/min. A pump rate of 150 bpm, pump ejection time of 120 ms, and stroke volume of 1 ml/kg were used during pulsatile CPB. Arterial blood samples were taken pre-CPB (36 degrees C), during normothermic CPB (35 degrees C), during hypothermic CPB (25 degrees C), pre-DHCA (18 degrees C), post-DHCA (19 degrees C), post-rewarming (35 degrees C), and post-CPB (36 degrees C). Viscosity and elasticity were measured at 2 Hz and 22 degrees C and at strains of 0.2, 1, and 5 using the Vilastic-3 Viscoelasticity Analyzer. Results suggest that the dual chamber neonate-infant pulsatile pump system produces less blood trauma than the standard nonpulsatile roller pump as indicated by lower values of both viscosity and elasticity during CPB support.

Mechanical ventilation

In this article Nigel Henderson discusses the nursing role in the mechanical ventilation of patients. He describes the different ventilator modes, and the physical and psychological care required by ventilated patients.

Behavioral phenotypes of inbred mouse strains: implications and recommendations for molecular studies

Choosing the best genetic strains of mice for developing a new knockout or transgenic mouse requires extensive knowledge of the endogenous traits of inbred strains. Background genes from the parental strains may interact with the mutated gene, in a manner which could severely compromise the interpretation of the mutant phenotype. The present overview summarizes the literature on a wide variety of behavioral traits for the 129, C57BL/6, DBA/2, and many other inbred strains of mice. Strain distributions are described for open field activity, learning and memory tasks, aggression, sexual and parental behaviors, acoustic startle and prepulse inhibition, and the behavioral actions of ethanol, nicotine, cocaine, opiates, antipsychotics, and anxiolytics. Using the referenced information, molecular geneticists can choose optimal parental strains of mice, and perhaps develop new embryonic stem cell progenitors, for new knockouts and transgenics to investigate gene function, and to serve as animal models in the development of novel therapeutics for human genetic diseases.

Influence of cyclic guanosine monophosphate changes on hemodynamics after reperfusion in liver transplantation

Orthotopic liver transplantation (OLT) is often associated with hemodynamic instability upon reperfusion, recognized as postreperfusion syndrome. Changes in vascular tone due to humoral factors released upon reperfusion of the graft have been suggested as a possible mechanism. In this study, we looked at the perioperative changes in cyclic guanosine monophosphate (cGMP), a mediator of vascular smooth muscle relaxation, and investigated its relationship with hemodynamic parameters. cGMP was measured in the plasma of 14 patients undergoing OLT by radioimmunoassay serially at the preanhepatic and anhepatic phases, and after reperfusion at 30, 60, and 120 min. Hemodynamic data recorded were systemic and pulmonary arterial pressures, cardiac output, and pulmonary and systemic vascular resistance. cGMP decreased markedly after reperfusion from a baseline level of 5.33+/-0.7 ng/ml to 1.63+/-0.5 ng/ml (P<0.01). Pulmonary arterial pressure increased from 17+/-1.21 mmHg to 23.5+/-1.9 mmHg (P<0.05), and pulmonary vascular resistance increased from 62.8 +/-12.9 dynes/sec/cm5 to 135+/-42.7 dynes/sec/cm5 (P<0.01). Changes in cardiac output and systemic vascular resistance were not significant. The changes in cGMP correlated with pulmonary arterial pressure (r=0.74, P=0.005) and pulmonary vascular resistance (r=0.7, P=0.01). These data confirm the occurrence of hemodynamic changes during OLT, and provide evidence to suggest that the reduction in cGMP after reperfusion may mediate the vascular changes.

Mechanisms of changes in renal handling of sodium following transjugular intrahepatic portal systemic stent-shunt (TIPSS)

BACKGROUND AND AIMS

Transjugular intrahepatic portosystemic stent-shunt (TIPSS) reduces the portal pressure gradient and leads to better control of ascites. The aim of this study was to evaluate (1) changes in renal handling of sodium following TIPSS and (2) the mechanism of these changes.

DESIGN

Prospective study.

SETTING

Tertiary referral centre for liver diseases.

METHODS

Eighteen patients with ascites undergoing TIPSS for recurrent variceal haemorrhage (16) (3 or more hospital admissions because of variceal haemorrhage whilst being treated endoscopically) or refractory ascites (2) were studied. Urinary sodium (UNa), creatinine clearance (CrCl), plasma renin activity (PRA), atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), Angiotensin II (AII) and lithium clearance (LiCl) were measured before and 3 months after TIPSS when portography was performed and the portal pressure gradient (PPG) also measured. All patients were haemodynamically stable and had received no diuretics for at least 1 week before blood sampling.

RESULTS

Improvement in ascites was achieved in all patients in whom TIPSS was inserted successfully (reduction in PPG to < 12 mmHg). PPG was reduced from a mean of 19 (+/-6) to 8.8 (+/-3.4) mmHg (P < 0.001). Urinary sodium and creatinine clearance improved significantly following TIPSS (P < 0.001, P < 0.001, respectively). PRA, All, cGMP and LiCl were abnormal before TIPSS and improved significantly following TIPSS (P < 0.007, P < 0.001, P < 0.001 and P < 0.01, respectively). ANP was not significantly different from normal controls and did not change significantly following TIPSS. Changes in UNa did not correlate with the Pugh score or the change in PPG.

CONCLUSION

The results of this study show that TIPSS is associated with significant improvement in UNa, CrCl, PRA, AII, cGMP and LiCl. The change in UNa following TIPSS was independent of the severity of underlying liver disease or the change in PPG.