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Combined delivery of neurotrophin-3 and NMDA receptors 2D subunit strengthens synaptic transmission in contused and staggered double hemisected spinal cord of neonatal rat.

We investigated whether administration of neurotrophin-3 (NT-3) and NMDA-2D-expressing units, found previously to enhance transmission in neonatal rat spinal cord, strengthens synaptic connections in the injured neonatal cord. We employed electrophysiological methods to evaluate the strength of synaptic transmission to individual motoneurons in the contusion and staggered double hemisection spinal cord injury (SCI) models. SCI at caudal thoracic levels (T11-T12) was carried out at postnatal day 2 (P2). Plugs containing NT-3- secreting fibroblasts and NR2D-expressing HSV-1 amplicons (HSVnr2d) were implanted above the lesion. Control animals were treated with an amplicon-expressing beta-galactosidase (HSVlac). After 8-10 days of treatment, the rats were sacrificed and spinal cords were removed for intracellular recording. Untreated contused cords preserved a fraction of white matter and weak monosynaptic responses were observed through the injury region. However, no synaptic connections were observed in control cords receiving double hemisection injury. Combined treatment with NT-3 and HSVnr2d strengthened monosynaptic connections in contused cords and induced the appearance of weak but functional multisynaptic connections in double hemisected cords. In contrast, treatment with either NT-3 or HSVnr2d alone failed to induce appearance of synaptic responses through the hemisected region. These results suggest that chronic treatment with NT-3 secreting fibroblasts combined with facilitated function of NMDA receptors by HSVnr2d treatment strengthens connections that survive incomplete SCI and therefore that such combined treatment might facilitate recovery of function following SCI.

Animals↗

Endothelial cell loss is not a major cause of neuronal and glial cell death following contusion injury of the spinal cord.

Contusion of the spinal cord causes an immediate local loss of neurons and disruption of vasculature; additional loss continues thereafter. To explore the possibility of a causal link between delayed endothelial cell (EC) death and secondary neural cell loss, we evaluated neural and endothelial cell survival, and measured inflammatory cell infiltration, at times up to 48 h after contusion injury to the adult rat thoracic spinal cord. Female Fischer rats (200 g), subjected to moderate (10 g x 12.5 mm) weight drop injuries by the MASCIS (NYU) impactor, were analyzed at 15 min and at 1, 8, 24 and 48 h. ECs, neurons, astrocytes, oligodendrocytes, neutrophils and activated macrophages/microglia were counted in transverse sections. At the injury site, 90% of all neurons died within 48 h of injury; no medium-large diameter neurons survived beyond 48 h. EC death occurred with kinetics similar to glial cell death. Because, in the injury site, most cell death occurred before 8 h, it preceded inflammatory cell infiltration. Three millimeters rostral and caudal to the injury epicenter neuronal numbers were stable for 8 h, and a sharp decrease in neuronal numbers beginning at 8 h strongly correlated with the onset of inflammatory cell infiltration. Glial and blood vessel numbers remained relatively stable in these areas up to 48 h. These results suggest that the loss of ECs during the first 48 h after a contusion injury is not a major cause of neuronal and glial cell death and, in tissue adjacent to the epicenter, inflammatory cell infiltration leads to neuronal loss.

Anaphase-Promoting Complex-Cyclosome↗

In situ detection of intracerebral cytokine expression after human brain contusion.

The study was undertaken to analyze intracerebral expression of pro- and anti-inflammatory cytokines after traumatic brain injury (TBI) in man in order to compare the findings with previous experimental data regarding the pathogenesis of secondary brain injury. Contused brain tissue biopsies were obtained from 12 consecutive patients undergoing surgery for brain contusions 3 h to 5 days after trauma. Cytokine expression was analyzed by in situ hybridization and immunohistochemistry. In patients undergoing surgery less than 24 h after trauma, strong expression of both the pro-inflammatory cytokines interleukin (IL)-1-beta, IL-6 and interferon (IFN)-gamma and the anti-inflammatory cytokine IL-4 was detected. In patients undergoing surgery between 3 and 5 days after trauma, IL-4 expression was significantly lower (P < 0.05) compared to the patients operated early. IL-1-beta and IFN-gamma expression remained strong in comparison to IL-6 and IL-4 expression (P < 0.05). Immunohistochemistry for IL-1-beta confirmed that the protein was produced with a temporal and regional pattern that corresponded to in situ hybridization results. The study provides in situ data on intracerebral cytokine expression after contusion in the clinical setting. Strong intracerebral cytokine expression occurs in the perilesional zone both in the early and the delayed phase after traumatic brain injury in humans. The temporal regulation of pro- and anti-inflammatory cytokines differs which reveals different therapeutic windows for pharmacological intervention.

Adolescent↗

Effects of mild hypothermia on cerebral blood flow-independent changes in cortical extracellular levels of amino acids following contusion trauma in the rat.

The mechanism of hypothermic cerebroprotection after traumatic brain injury (TBI) is unknown. The present study was conducted to investigate the effects of mild hypothermia on the changes in cortical extracellular amino acids and cerebral blood flow (CBF) caused by cerebral contusion created in the rat parietal cortex by a weight-drop method. CBF in both normothermia (37 degrees C) and hypothermia (32 degrees C) groups, which was monitored using the hydrogen clearance technique, decreased significantly after contusion, but never fell below the threshold for ischemia. Cortical levels of glutamate, aspartate, glycine and taurine, which were measured by intracerebral microdialysis, were significantly increased after contusion in each group. However, these increases were greater in the hypothermic than in the normothermic rats. Normal plasma amino acid levels were high, and autoradiography following intravenous injection of 14C-labeled glutamate revealed marked extravasation of [14C]glutamate at the site of cortical impact. These results suggest that the post-traumatic increase in extracellular amino acids occurs independently of CBF reduction, and that extravasation of amino acids from the vascular compartment partly contributes to this increase. Hypothermic cerebroprotection in TBI is thus likely to occur through a mechanism other than reduction in interstitial excitatory amino acids. In TBI, it is postulated that the postsynaptic effects of hypothermia may be more important than the presynaptic effects, when CBF is kept above the ischemic threshold.

Amino Acids↗

Spinal cord contusion models.

Most human spinal cord injuries involve contusions of the spinal cord. Many investigators have long used weight-drop contusion animal models to study the pathophysiology and genetic responses of spinal cord injury. All spinal cord injury therapies tested to date in clinical trial were validated in such models. In recent years, the trend has been towards use of rats for spinal cord injury studies. The MASCIS Impactor is a well-standardized rat spinal cord contusion model that produces very consistent graded spinal cord damage that linearly predicts 24-h lesion volumes, 6-week white matter sparing, and locomotor recovery in rats. All aspects of the model, including anesthesia for male and female rats, age rather than body weight criteria, and arterial blood gases were empirically selected to enhance the consistency of injury.

Animals↗

Does endogenous progesterone promote recovery of chronic sensorimotor deficits following contusion to the forelimb representation of the sensorimotor cortex?

We studied sensorimotor recovery in male, normal-cycling and pseudopregnant female rats following unilateral FL-SMC contusions. Forelimb use (push off before a rear, support against the walls, and landing after a rear) and the foot fault test (foot misplacements during locomotion on an elevated grid) were analyzed from videotapes taken before surgery, and then again on post-surgical days 2 and 36. High endogenous progesterone levels in females at the time of injury did not affect recovery as there were no differences between males, pseudopregnant females and normal-cycling female rats on these behaviors. None of the brain-injured rats recovered symmetrical forelimb use between 2 and 36 days after injury (P>0.05) and they also showed foot misplacements (P>0.05) in the foot fault test. Male and female rats with contusions had fewer mean foot misplacements on day 36 than 2 days after injury (P<0.001), indicating that there was partial recovery on this task. These results were taken to show that there were no sex differences in motor deficits caused by unilateral FL-SMC injury. In addition, higher endogenous progesterone levels in females did not protect them from the chronic sensorimotor deficits caused by unilateral FL-SMC contusions.

Animals↗

[Lung contusion: relevance of initial injured pulmonary volume measurement by computed tomography].

OBJECTIVE: To evaluate computed tomography quantification of injured pulmonary volume after thoracic trauma and its relevance for severity grade of patients with lung contusion. STUDY DESIGN: Retrospective study in a major French Level I university trauma center. PATIENTS AND METHODS: Clinical and biological data including oxygenation index (PaO2/FIO2) and therapeutics modalities during the first 5 days: positive end expiratory pressure (Peep) and nitric oxide (NO), were collected on 49 patients with lung contusion resulting from thoracic trauma. Injured pulmonary volume was evaluated on initial thoracic tomodensitometry by 2 senior radiologists. The correlation between oxygenation index, therapeutics modalities and initial injured pulmonary volume was assessed for signification. RESULTS: Injured pulmonary volume larger than 37.75% of total lung volume is associated with both hypoxemia at the twenty-fourth hour (PaO2/FIO2 <300), and need for Peep >6 cm H2O and /or ongoing NO administration on day 5. CONCLUSION: Injured parenchymal pulmonary volume evaluation on initial tomodensitometry seems to be an important indicator of lung contusion severity. Thoracic computed tomography provides additional prognostic information in the initial evaluation of thoracic trauma with parenchymal injury.

Adolescent↗

Regional changes in interstitial K+ and Ca2+ levels following cortical compression contusion trauma in rats.

Brain trauma is associated with acute functional impairment and neuronal injury. At present, it is unclear to what extent disturbances in ion homeostasis are involved in these changes. We used ion-selective microelectrodes to register interstitial potassium ([K+]e) and calcium ([Ca2+]e) concentrations in the brain cortex following cerebral compression contusion in the rat. The trauma was produced by dropping a 21 g weight from a height of 35 cm onto a piston that compressed the cortex 1.5 mm. Ion measurements were made in two different locations of the contused region: in the perimeter, i.e., the shear stress zone (region A), and in the center (region B). The trauma resulted in an immediate increase in [K+]e from a control level of 3 mM to a level > 60 mM in both regions, and a concomitant negative shift in DC potential. In both regions, there was a simultaneous, dramatic decrease in [Ca2+]e from a baseline of 1.1 mM to 0.3-0.1 mM. Interstitial [K+] and the DC potential normalized within 3 min after trauma. In region B, [Ca2+]e recovered to near control levels within 5 min after ictus. In region A, however, recovery of [Ca2+]e was significantly slower, with a return to near baseline values within 50 min after trauma. The prolonged lowering of [Ca2+]e in region A was associated with an inability to propagate cortical spreading depression, suggesting a profound functional disturbance. Histologic evaluation 72 h after trauma revealed that neuronal injury was confined exclusively to region A. The results indicate that compression contusion trauma produces a transient membrane depolarization associated with a pronounced cellular release of K+ and a massive Ca2+ entry into the intracellular compartment. We suggest that the acute functional impairment and the subsequent neuronal injury in region A is caused by the prolonged disturbance of cellular calcium homeostasis mediated by leaky membranes exposed to shear stress.

Animals↗

Spontaneous and amphetamine-evoked release of cerebellar noradrenaline after sensorimotor cortex contusion: an in vivo microdialysis study in the awake rat.

Microdialysis sampling combined with HPLC was used to assess spontaneous and d-amphetamine (AMPH)-evoked release of noradrenaline (NA) in the cerebellum 1 day after probe implantation and 1 day after contusion of the right sensorimotor cortex (SMCX) in rats. In normal controls the mean +/- SEM basal NA release was 10.08 +/- 0.97 pg in the left cerebellar hemisphere and 8.21 +/- 1.17 pg in the right hemisphere 22-24 h after probe implantation. The average +/- SEM NA release in a 3-h period after administration of AMPH (2 mg/kg, i.p.) increased to 453 +/- 47.35 pg in the left and to 402 +/- 49.95 pg in the right cerebellar hemisphere. NA release (range of 413-951% increase over baseline) was maximal 20-40 min postdrug, returned to basal levels within 5 h, and remained unchanged for the 22-24-h postdrug measurement period. Animals with a focal SMCX contusion had a marked depression of both spontaneous and AMPH-evoked NA release. Mean +/- SEM basal NA release was 4.84 +/- 1.09 pg in the left and 4.95 +/- 0.43 pg in the right cerebellar hemisphere from 22 to 24 h postinjury, with NA levels increasing to 259 +/- 75.44 and 219 +/- 23.45 pg in the respective hemispheres over a 3-h period after AMPH. The maximal AMPH-induced increase in NA release ranged from 522 to 1,088% of basal levels in contused rats, with NA release returning to predrug levels within 5 h and remaining depressed for at least 48 h postinjury.(ABSTRACT TRUNCATED AT 250 WORDS)

Amphetamine↗

Brain stem contusion due to tentorial coup injury: case report and pathomechanical analysis from normal cadavers.

This report is in two parts. First, a case report on a 20-year-old man with a localized brain stem contusion. Second, in order to elucidate the mechanism of this injury, an anatomical study was performed. Ten cadaver heads were analysed to reveal the variations of spatial anatomy around the tentorial incisura. The lateral tentorial incisura (lateral to brain stem) was situated at the level of pontomesencephalic junction and nearest to the brain stem along its course. The shortest distance between them averaged 1.0 mm (0-4 mm). Based on these findings, primary brain stem injury caused by tentorial incisura occurs at its lateral portion due to the shortest distance to the brain stem and near the level of pontomesencephalic junction. In patients with a tentorial incisura closely related to or touching the brain stem, tentorial coup injury to the brain stem may occur even with a relatively minor injury. In our case, repeated CT and MRI proved that the location of contusion was at the pontomesencephalic junction, coinciding with the level of the tentorial edge. The injury started at the surface of brain stem. The tentorial edge was close to brain stem in this case. These radiological findings support the hypothesis that the brain stem contusion was caused by a tentorial coup injury.

Adult↗

Enhanced lipid peroxidation processes in patients after brain contusion.

Erythrocyte superoxide dismutase (SOD-1) activity and cerebrospinal fluid (CSF), blood plasma low-density lipoprotein (LDL) and erythrocyte thiobarbituric acid reactive substance (TBARS) concentrations were determined in 30 patients with brain contusion and in 37 control patients with low back pain due to noninflammatory degenerative lumbar disc disease. In comparison to controls, during 10-day follow-up patients with brain contusion had significantly increased erythrocyte SOD-1 activity and CSF, blood plasma (LDL), and erythrocyte TBARS concentrations. The highest CSF TBARS concentrations were observed in five patients who died 2, 7, or 8 days following head injury. A significant negative correlation was found between erythrocyte SOD-1 activity or TBARS concentrations, in the blood plasma LDL fraction and erythrocytes, and The Glasgow Coma Scale score. These results suggest that enhanced lipid peroxidation processes, which seem to correlate with the severity of head injury, accompany brain contusion.

Adolescent↗

Skeletal muscle adaptations following spinal cord contusion injury in rat and the relationship to locomotor function: a time course study.

Experimental spinal cord injury (SCI) via contusion of moderate severity results in residual locomotor deficits, including a lack of coordination and trunk stability. Given that muscle contractile properties and fiber composition adapt to reduced neural input and/or weight bearing, contusion-induced locomotor deficits may reflect changes in hindlimb skeletal muscle. Therefore, we examined muscle adaptations during early (1 week), intermediate (3 week), and late (10 week) stages of motor recovery after moderate SCI. Forty-two Sprague Dawley rats underwent SCI via 1.1mm cord displacement with the OSU impact device or served as age and weight-matched or laminectomy controls. Subsets of rats had soleus (SOL) in vitro physiological testing or SOL and extensor digitorum longus (EDL) myosin heavy chain (MHC) fiber type analysis. At 1 week post-SCI during paralysis/paresis, a significant decrease in wet weight occurred in the plantaris, medial/lateral gastrocnemius (MG/LG), tibialis anterior, and SOL. Changes in contractile properties of the SOL did not accompany muscle wet weight changes. By 3 weeks, the loss of weight-bearing activity early after SCI induced significant decreases in SOL peak twitch and peak tetanic tension as well as significantly greater IIx MHC expression in the EDL. By 10 weeks post-SCI, after several weeks of weight supported stepping, muscle wet weight, contractile properties and MHC composition returned to baseline levels except for MG/LG atrophy. Thus, muscle plasticity appears to be extremely sensitive to locomotor deficits and their resolution after moderate spinal cord contusion.

Adaptation, Physiological↗

Methylprednisolone and interleukin-10 reduce gray matter damage in the contused Fischer rat thoracic spinal cord but do not improve functional outcome.

The effects of two antiinflammatory and neuroprotective agents, methylprednisolone (MP) and interleukin-10 (IL-10), singly and in combination on tissue damage, axonal preservation and functional recovery were studied in the contused adult Fischer rat thoracic spinal cord 12 weeks after injury. MP (30 mg/kg at 5 min, and 2 and 4 h after injury) was administered intravenously and IL-10 (15 or 30 microg/kg at 30 min after injury), intraperitoneally. MP, IL-10, or the combination significantly reduced the volume of damaged tissue (including cavities) compared to control animals. The loss of spinal tissue (cavities) was reduced after treatment with MP alone or combined with IL-10, but not with IL-10 alone. The reduction in tissue damage was confined to spinal gray matter; at the level of the lesion epicenter, the thickness of the lateral white matter columns was similar in all groups. Retrograde tracing using fast blue revealed that the number of spared propriospinal and supraspinal projections was similar in all groups at 12 weeks after the contusion. The open-field BBB-test showed no significant difference in hindlimb locomotion between groups. Our results demonstrate that all tested antiinflammatory treatments significantly increase the volume of spared spinal gray matter 3 months after a moderate contusion of the Fischer rat thoracic spinal cord, but none of the treatments improved axonal preservation or functional recovery.

Animals↗

Hyperbaric oxygen therapy for reduction of secondary brain damage in head injury: an animal model of brain contusion.

Cerebral contusions are one the most frequent traumatic lesions and the most common indication for secondary surgical decompression. The purpose of this study was to investigate the physiology of perilesional secondary brain damage and evaluate the value of hyperbaric oxygen therapy (HBOT) in the treatment of these lesions. Five groups of five Sprague-Dawley rats each were submitted to dynamic cortical deformation (DCD) induced by negative pressure applied to the cortex. Cerebral lesions produced by DCD at the vacuum site proved to be reproducible. The study protocol entailed the following: (1) DCD alone, (2) DCD and HBOT, (3) DCD and post-operative hypoxia and HBOT, (4) DCD, post-operative hypoxia and HBOT, and (5) DCD and normobaric hyperoxia. Animals were sacrificed after 4 days. Histological sections showed localized gross tissue loss in the cortex at injury site, along with hemorrhage. In all cases, the severity of secondary brain damage was assessed by counting the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and caspase 3-positive cells in successive perilesional layers, each 0.5 mm thick. Perilesional TUNEL positive cells suggested the involvement of apoptosis in group 1 (12.24% of positive cells in layer 1). These findings were significantly enhanced by post-operative hypoxia (31.75%, p < 0.001). HBOT significantly reduced the severity and extent of secondary brain damage expressed by the number of TUNEL positive cells in each layer and the volume of the lesion (4.7% and 9% of TUNEL positive cells in layer 1 in groups 2 and 4 respectively, p < 0.0001 and p < 0.003). Normobaric hyperoxia also proved to be beneficial although in a lesser extent. This study demonstrates that the vacuum model of brain injury is a reproducible model of cerebral contusion. The current findings also suggest that HBOT may limit the growth of cerebral contusions and justify further experimental studies.

Animals↗

Spinal cord sodium, potassium, calcium, and water concentration changes in rats after graded contusion injury.

Spinal cord Na, K, Ca, and H2O changes were measured 6 h after graded contusion injuries in 40 Sprague-Dawley rats. A 10 g weight was dropped 1.25 cm (n = 6), 2.5 cm (n = 7), 5.0 cm (n = 6), or 7.5 cm (n = 7) onto the thoracic spinal cord of 26 rats. An additional 10 rats served as laminectomy controls and 4 rats were unoperated controls. At 6 h after surgery or injury, the spinal cords were rapidly cut into 4 mm segments, weighed to obtain tissue wet weights (W), dried for 14-16 h at 97 degrees C in a vacuum oven (30 mmHg), and reweighed for tissue dry weights (D). Water concentrations ([H2O]d) were estimated from (W-D)/D in units of ml/g D. Ionic concentrations ([Na]d, [K]d, and [Ca]d) of the tissue samples were measured by atomic absorption spectroscopy with units of mumol/g D. Ionic shifts (delta [Na]d, delta [K]d, delta [Ca]d) were calculated by subtracting laminectomy control values from those measured in injured cords. Laminectomy alone significantly increased [Na]d and [H2O]d compared to unoperated controls. Mean +/- standard deviations of [H2O]d, [Na]d, [K]d, and [Ca]d were, respectively, 1.95 +/- 0.07, 182.6 +/- 5.9, 277.2 +/- 11.8, and 12.1 +/- 1.4 in unoperated controls; 2.12 +/- 0.08, 238.6 +/- 9.2, 277.8 +/- 9.2, and 11.7 +/- 1.1 in laminectomy controls. At the impact site, [K]d fell by 14-37% and [H2O]d rose by 14-24%, [Na]d by 13-64%, and [Ca]d by 65-137% of laminectomy control values. delta [Na]d, delta [K]d, and delta [Ca]d correlated linearly with impact velocities; [Ca]d increased by 1.0% per cm/sec (r = 0.995, p less than 0.005), [Na]d increased 0.67% per cm/sec (r = 0.950, p less than 0.01), and [K]d decreased 0.34% per cm/sec (r = 0.964, p less than 0.01). Neither delta [H2O] nor delta [Na]d + delta [K]d consistently predicted impact velocity. [Na]d + [K]d correlated with [H2O]d with a slope of 177.4 mumol/ml (r = 0.697, p less than 0.005). Since Na and K constitute greater than 95% of tissue inorganic ions, the slope approximates net ionic shift per ml of water entry or the ionic osmolarity of edema fluid. These results indicate that increasing contusions produce graded ionic shifts and that edema does not predict contusion severity. These data support our hypothesis that net ionic shifts cause edema in injured spinal cords.

Animals↗

Lumbar puncture delivery of bone marrow stromal cells in spinal cord contusion: a novel method for minimally invasive cell transplantation.

Cell transplantation as a treatment for spinal cord injury is a promising therapeutic strategy whose effective clinical application would be facilitated by non-invasive delivery protocols. Cells derived from the bone marrow are particularly attractive because they can be obtained easily, expanded to large numbers and potentially used for autologous as well as allogeneic transplantation. In this study we tested the feasibility of a novel minimally invasive method--lumbar puncture (LP)--for transplanting bone marrow stromal stem cells (MSC) into a clinically relevant spinal cord contusion model. We further sought to determine optimal protocols for performing such minimally invasive cell transplantation. Sprague-Dawley rats received a moderate contusion injury at the midthoracic level followed by LP transplantation of MSC derived from transgenic rats that express the human placental alkaline phosphatase (AP) reporter gene. The recipients were analyzed histologically to evaluate the extent of cell delivery and survival at the injury site. We found that MSC delivered by LP reached the contused spinal cord tissues and exerted a significant beneficial effect by reducing cyst and injury size. Transplantation within 14 days of injury provided significantly greater grafting efficiency than more delayed delivery, and increasing MSC dosage improved cell engraftment. The techniques described here can easily be translated to patients, thus accelerating clinical application of stem cell therapies.

Alkaline Phosphatase↗

Cardiac troponin I and myocardial contusion in the rabbit.

BACKGROUND: Patients with cardiac contusion have a high risk of cardiac complications during emergency anesthesia. Despite the progress in cardiac imaging, a biologic marker of myocardial damage such as cardiac troponin I remains useful and has been proposed in clinical practice. The relationship among histologic injury, left-ventricular function, and release of cardiac enzymes and cardiac troponin I has been investigated after a controlled myocardial contusion in a rabbit model. METHODS: A global trauma (two levels of energy: 250 and 350 mJ) was produced on an isolated preparation of rabbit's heart, of which the temperature, perfusion flow, beating rate, and left-ventricular volume were kept constant. Left-ventricular pressure and its first derivative as a function of time were measured during a 60-min period after the blow; a timed collection of the effluent was made to assess creatine kinase, lactate dehydrogenase, and cardiac troponin I. At the end of the period, an anatomic score of the contusion was calculated by histologic examination of the hearts. RESULTS: Compared with a control group, the two levels of cardiac trauma resulted in a proportional anatomic injury significantly correlated with left-ventricular dysfunction (Delta%dP/dtmax = -16 +/- 12 and -36 +/- 20% at 3 min, mean +/- SD). Transient releases in cardiac markers after the lesser amount of trauma contrasted with a prolonged and biphasic release of cardiac troponin I after the greater amount. Peak cardiac troponin I level was correlated with anatomic injury (rho = 0.596, P= 0.001) and negatively correlated with left-ventricular dysfunction (r = -0.375, P= 0.04). CONCLUSION: Cardiac troponin I is a marker of anatomic and functional consequences of experimental cardiac trauma and may be a predictive indicator of early posttraumatic cardiac complications during the postoperative period.

Animals↗

Creatine phosphokinase-MB assays in patients with suspected myocardial contusion: diagnostic test or test of diagnosis?

To clarify the role of serum CPK-MB assays in the diagnosis of myocardial contusion, we reviewed the hospital records of 182 patients with significant blunt chest trauma and serial CPK-MB determinations. In our laboratory a serum CPK-MB/CPK ratio less than 2.2% is abnormal. The study group was composed of 131 men and 51 women, with a mean age of 35 years. Only six patients had histories of cardiac disease. Of 159 patients injured in vehicular accidents, 143 were drivers, nine were pedestrians, and seven were passengers. There was no relationship between the MB fraction and soft (nonspecific changes) or strongly suggestive (ectopy, focal changes) ECG signs of myocardial contusion. Two of the three patients with power failure had CPK-MB/CPK ratios less than 2.2%. MUGA scans, performed in 18 patients, indicated myocardial injury in seven patients; only 1/7 had abnormal 2D echocardiography, and only 2/7 had elevated MB fractions. In summary, we found no relationship between serum CPK-MB and the presence of clinically significant myocardial contusion. CPK-MB determination in patients with suspected blunt myocardial injury is unjustifiably expensive ($108/assay) and adds confusion to an already vague clinical area.

Accidents, Traffic↗