Kosaku Kinoshita

Interleukin-1β messenger ribonucleic acid and protein levels after fluid-percussion brain injury in rats: Importance of injury severity and brain temperature

OBJECTIVE Posttraumatic temperature manipulations have been reported to significantly influence the inflammatory response to traumatic brain injury (TBI). The purpose of this study was to determine the temporal and regional profiles of messenger ribonucleic acid (mRNA) expression and protein levels for the proinflammatory cytokine interleukin-1&bgr; (IL-1&bgr;), after moderate or severe TBI. The effects of posttraumatic hypothermia (33°C) or hyperthermia (39.5°C) on these consequences of TBI were then determined. METHODS Male Sprague-Dawley rats underwent fluid-percussion brain injury. In the first phase of the study, rats were killed 15 minutes or 1, 3, or 24 hours after moderate TBI (1.8–2.2 atmospheres), for reverse transcription-polymerase chain reaction analysis. Other groups of rats were killed 1, 3, 24, or 72 hours after moderate or severe TBI (2.4–2.7 atmospheres), for protein analysis. In the second phase, rats underwent moderate fluid-percussion brain injury, followed immediately by 3 hours of posttraumatic normothermia (37°C), hyperthermia (39.5°C), or hypothermia (33°C), and were then killed, for analyses of protein levels and mRNA expression. Brain samples, including cerebral cortex, hippocampus, thalamus, and cerebellum, were dissected and stored at −80°C until analyzed. RESULTS The findings indicated that mRNA levels were increased (P < 0.05) as early as 1 hour after TBI and remained elevated up to 3 hours after moderate TBI. Although both moderate and severe TBI induced increased levels of IL-1&bgr; (P < 0.05), increased protein levels were also noted in remote brain structures after severe TBI. Posttraumatic hypothermia attenuated IL-1&bgr; protein levels, compared with normothermia (P < 0.05), although the levels remained elevated in comparison with sham values. In contrast, hyperthermia had no significant effect on IL-1&bgr; levels, compared with normothermic values. Posttraumatic temperature manipulations had no significant effect on IL-1&bgr; mRNA levels. CONCLUSION Injury severity determines the degree of IL-1&bgr; protein level elevation after TBI. The effects of posttraumatic hypothermia on IL-1&bgr; protein levels (an important mediator of neurodegeneration after TBI) may partly explain the established effects of posttraumatic temperature manipulations on inflammatory processes after TBI.

Tumor Necrosis Factor α Expression and Protein Levels after Fluid Percussion Injury in Rats: The Effect of Injury Severity and Brain Temperature

OBJECTIVE:Tumor necrosis factor &agr; (TNF&agr;) is elevated in some models of traumatic brain injury (TBI). However, it is unclear how TNF&agr; messenger ribonucleic acid (mRNA) expression and protein levels are affected by injury severity and posttraumatic temperature modification. This study determined the regional and temporal profile of TNF&agr; levels after moderate and severe TBI and assessed the effects of posttraumatic hypothermia or hyperthermia on this proinflammatory cytokine. METHODS:Adult male Sprague-Dawley rats were subjected to sham procedures (no injury), moderate fluid-percussion TBI (1.8–2.2 atm), or severe fluid-percussion TBI (2.4–2.6 atm). After 1 to 72 hours of survival, animals were killed, and brain samples, cerebrospinal fluid, and serum were harvested for enzyme-linked immunosorbent assay quantification of TNF&agr; levels. In a subsequent study, a 3-hour period of post-traumatic hypothermia (33°C) or hyperthermia (39.5°C) was applied, followed by immediate killing and cytokine assay. Another group was subjected to moderate TBI (1.8–2.2 atm), followed by killing at 15 minutes or at 1, 3, or 24 hours for TNF&agr; reverse transcriptase-polymerase chain reaction analysis. RESULTS:A significant increase in TNF&agr; mRNA and protein levels in cellular lysates of injured cortex and ipsilateral hippocampus was noted by 1 hour after TBI; it was sustained to 3 hours, followed by a rapid decline. Increased injury severity was associated with increased protein levels at remote injury sites and in the injured cerebral cortex at 72 hours. Posttraumatic hypothermia significantly reduced TNF&agr; mRNA expression in the hippocampus compared with that in normothermic rats. In contrast, no temperature effects on TNF&agr; protein levels were documented. CONCLUSION:Rapid and marked increase in TNF&agr; mRNA expression and protein levels follows moderate and severe TBI. Injury severity and posttraumatic temperature play a modest but significant role on TNF&agr; expression and protein levels. These findings suggest that the effects of posttraumatic temperature on histopathological and behavioral outcome primarily may involve secondary mediators that do not operate directly through their effect on TNF&agr;.

The role of inflammatory processes in the pathophysiology and treatment of brain and spinal cord trauma

Traumatic injury to the brain and spinal cord results in an early inflammatory response that is initiated by the release of proinflammatory cytokines followed by the infiltration and accumulation of polymorphonuclear leukocytes (PMNLs). The role of the inflammatory cascade on traumatic outcome remains controversial. Pleiotropic cytokines appear to function both protectively and destructively. The induction of cytokines can lead to the expression of the inducible form of nitric oxide synthase (iNOS), which in turn provokes the release of excessive amounts of nitric oxide (NO) that may participate in the pathogenesis of tissue injury. Hypothermia has been reported by various groups to be neuroprotective in brain and spinal cord trauma. We studied the effect of therapeutic hypothermia on cerebral IL-1beta concentrations, PMNL accumulation and iNOS activity after traumatic brain injury (TBI) and spinal cord injury (SCI). Based on current data therapeutic hypothermia may protect in models of traumatic injury by modulating deleterious inflammatory processes.

Reduced effectiveness of vasopressin in repeated doses for patients undergoing prolonged cardiopulmonary resuscitation

INTRODUCTION The efficacy of repeated administration of vasopressin alone during prolonged cardiopulmonary resuscitation (CPR) remains unconfirmed. This study was conducted to estimate the effectiveness of the repeated administration of vasopressin vs. epinephrine for cardiopulmonary arrest (CPA) patients receiving prolonged CPR. METHODS We conducted a prospective randomized controlled study on patients who experienced out-of-hospital CPA. The patients were randomly assigned to receive a maximum of four injections of either 40IU of vasopressin (vasopressin group) or 1mg of epinephrine (epinephrine group) immediately after emergency room (ER) admission. Patients who received vasopressors before ER admission or suffered non-cardiogenic CPA were excluded after randomization. RESULTS In total, 336 patients were enrolled (vasopressin group, n=137; epinephrine group, n=118). No differences were found between these groups (vasopressin group vs. epinephrine group) in the rates of return of spontaneous circulation (ROSC) (28.7% vs. 26.6%), 24-h survival (16.9% vs. 20.3%), or survival to hospital discharge (5.6% vs. 3.8%). In a subgroup analysis by the Fishers exact test, the rate of ROSC was higher in the vasopressin group than in the epinephrine group, among the patients whose arrests were witnessed (48.1% vs. 27.8%, p=0.010) or who received bystander CPR (68.0% vs. 38.5%, p=0.033). When the independent predictors of ROSC were calculated in the subgroup analysis, however, vasopressin administration (Odds ratio: 0.87-0.28) did not affect the outcome. CONCLUSIONS This is the first report of a possible vasopressin-alone resuscitation without additional epinephrine. However, repeated injections of either vasopressin or epinephrine during prolonged advanced cardiac life support resulted in comparable survival.

Effect of Posttraumatic Hyperglycemia on Contusion Volume and Neutrophil Accumulation after Moderate Fluid-Percussion Brain Injury in Rats

The purpose of this study was to evaluate the effects of posttraumatic hyperglycemia on contusion volume and neutrophil accumulation following moderate traumatic brain injury (TBI) in rats. A parasagittal fluid-percussion (F-P) brain injury (1.8-2.1 atm) was induced in male Sprague-Dawley rats. Rats were then randomized into four trauma groups (n = 7/group) by the timing of dextrose injection (2.0 gm/kg/ip), which included (1) early (E) group: 5 min after TBI; (2) delayed (D) group: 4 h after TBI; (3) 24-h group: 24 h after TBI; or (4) control (C) group: no dextrose injection. A sham operated control group also received dextrose to document physiological parameters (n = 4). Rats were perfusion fixed 3 days following TBI, and the brains were processed for routine histopathological and immunocytochemical analysis. Contusion areas and volumes, as well as the frequency of myeloperoxidase immunoreactive polymorphonuclear leukocytes (PMNLs) were determined. Dextrose injections significantly increased blood glucose levels (p < 0.005) in all treated groups. Although acute hyperglycemia following TBI did not significantly affect total contusion volume, contusion area was significantly elevated in the early treatment group. In addition, early posttraumatic hyperglycemia enhanced neutrophil accumulation in the area of the cortical contusion (p < 0.005). In contrast, delayed induced hyperglycemia (i.e., 4 h, 24 h) did not significantly affect histopathological outcome or neutrophil accumulation. Taken together, these findings indicate that acute but not delayed hyperglycemia aggravates histopathological outcome and increased accumulation of PMNLs. Posttraumatic hyperglycemia in the acute phase may worsen traumatic outcome by enhancing secondary injury processes, including inflammation.

The Clinical Issue and Effectiveness of Brain Hypothermia Treatment for Severely Brain-Injured Patients

Treatment for brain injury has focused on neuroprotection against brain edema, brain ischemia, and control of intracranial hypertension in animal studies. However, these concepts are not successful in the management of in severely brain-injured patients, because animal studies do not include information about the influence of the excess response of systemic circulatory-metabolic changes and hypothalamus-pituitary endocrine axis dysfunction caused by anesthesia. In our recent clinical studies of severe brain injury, the management of restoration therapy of dying neurons in injured brain tissue before neuroprotection therapy produced successful clinical results. Three major targets of treatment are important: Adequate administration of oxygen and metabolic substrates, control of excess release of vasopressin and growth hormone for prevention of blood-brain barrier dysfunction and cytokine encephalitis, and preclusion of selective neuronal radical damage of the dopamine A 10 nervous system for prevention of vegetation. Management of intensive care is focused on three subsequent targets: Initial care management is to maintain sufficient cerebral oxygenation and adequate brain metabolism by control of PaO2/FiO2above 300, systolic blood pressure above l00 mmHg, serum glucose at 120–140mg/dl, brain temperature at 34°-32°C, ICP below 20 mmHg, antithrombin-III (AT-III) above 100%, hemoglobin 2,3 diphosphoglycerate at 12–15 mmol/mL, serum pH above 7.3, oxygen delivery above 800ml/min, and fluid resuscitation. The second target is control of hypothalamus-pituitary axis activation by management of brain tissue temperature at 34°C with 120–140 mg/d serum glucose, 9% saline followed by 4% saline fluid resuscitation, AT-III above 100% followed by replacement of albumin drip, and maintaining serum albumin higher than 3.5g/dl within 2–3 h after injury. The third target is to prevent the selective neuronal damage of the dopamine A 10 nervous system by controlling brain tissue temperature at 32°-33°C with management of Hb above 11 g/dl and administration of vitamin E and C. However, in brain hypothermia treatment, there are five major pitfalls: hemoglobin dysfunction associated with masking brain hypoxia, inadequate management of brain tissue temperature with hyperglycemia, undesirable duration of brain hypothermia, inadequate care management of systemic infections, and misunderstanding of nutritional issues in the management of brain injury. These pitfalls are discussed in this chapter. A novel technique for control of these clinical issues, the success of adequate neuronal oxygenation and brain metabolism, neurohormonal control of the blood-brain barrier dysfunction, and preservation of the dopamine A 10 nervous system are explained. Prevention of brain edema, elevation of ICP, and neuroexcitaion are not mechanisms of brain hypothermia. The effectiveness of brain hypothermia treatment was studied by comparing the clinical results of brain hypothermia (99 cases) and normothermia (65 cases) of head injury with Glascow Coma Scale (GCS) less than 6. Patients with initial GCS scores of 3 did not benefit from brain hypothermia treatment, but with GCS 4, 5, and 6, clinical benefit was observed. As clinical signs, memory, intelhgence, and personality were not much disturbed in the brain hypothermia-treated group.

Post-ischemic potentiation of Schaffer collateral/CA1 pyramidal cell responses of the rat hippocampus in vivo: involvement of N-methyl-d-aspartate receptors

The present study examined the functional changes in the hippocampal CA1 pyramidal cell system in vivo occurring after 12-min forebrain ischemia in the rat. A population excitatory postsynaptic potential and orthodromic population spike of CA1 pyramidal cells to stimulation of the Schaffer collaterals were potentiated at 6-8 h post-ischemia. These changes were not associated with an increase in excitability of the CA1 pyramidal cells as evaluated from the antidromic population spike induced by alveus stimulation, suggesting the presence of an increased synaptic efficacy. The post-ischemic potentiation was prevented by pretreatment with the N-methyl D-aspartate (NMDA) receptor antagonist, MK801, in a dose-dependent manner. These findings suggest that 12-min forebrain ischemia in the rat activates NMDA receptors, which results in an increase in synaptic efficacy to the CA1 pyramidal cells at 6-8 h post-ischemia.

Effects of Bag-mask versus Advanced Airway Ventilation for Patients Undergoing Prolonged Cardiopulmonary Resuscitation in Pre-hospital Setting

BACKGROUND There is no evidence that the advanced airway ventilation (AAV) method improves patient outcome in the pre-hospital cardiac arrest setting. OBJECTIVE The aim of this study was to estimate the effectiveness of AAV vs. bag-mask ventilation (BMV) for cardiopulmonary arrest (CPA) patients, when administered by a licensed emergency medical technician in the pre-hospital setting. METHODS The study used the database of patients who suffered out-of-hospital cardiogenic CPA from 2006 to 2007 in our hospital. Patient records were searched for the method of pre-hospital airway management (BMV or AAV) and the patients outcomes were compared between groups. The primary endpoint was a favorable neurological outcome; the secondary endpoints were rate of return of spontaneous circulation (ROSC) and rate of admission to the intensive care unit (ICU). RESULTS A total of 355 CPA patients (156 BMV and 199 AAV) were retrospectively enrolled. There was no significant difference in demographics between the two groups. The transportation time exceeded 30 min in both groups. The overall ROSC rate and ICU admission rate were significantly higher in the AAV group (p = 0.0352 and p = 0.0089, respectively). The data showed that AAV (odds ratio 1.960; 95% confidence interval 1.015-3.785) resulted in a higher overall ROSC rate than BMV, but there were no significant differences in either the rate of pre-hospital ROSC or in favorable neurological outcome. CONCLUSION AAV may yield advantages over BMV in the overall rate of ROSC in CPA patients, but both approaches for airway management in this study resulted in a comparably favorable neurological outcome. Earlier ROSC would be required for improved overall outcome.

Shorter time until return of spontaneous circulation is the only independent factor for a good neurological outcome in patients with postcardiac arrest syndrome

Objective Few studies have reported factors that result in a better neurological outcome in patients with postcardiac arrest syndrome (PCAS) following return of spontaneous circulation (ROSC). We investigated the factors affecting neurological outcome in terms of both prehospital care and treatments after arrival at hospital in patients with PCAS. Methods The study enrolled patients with cardiogenic cardiac arrest who were admitted to an intensive care unit after ROSC with PCAS. We investigated the association of the following factors with outcome: age, gender, witness to event present, bystander cardiopulmonary resuscitation (CPR) performed, ECG waveform at the scene, time interval from receipt of call to arrival of emergency personnel, time interval from receipt of call to arrival at hospital, prehospital defibrillation performed, special procedures performed by emergency medical technician, and time interval from receipt of call to ROSC, coronary angiography/percutaneous coronary intervention (PCI) and therapeutic hypothermia performed. Results The study enrolled 227 patients with PCAS. Compared with the poor neurological outcome group, the good neurological outcome group had a statistically significant higher proportion of the following factors: younger age, male, witness present, bystander CPR performed, first ECG showed ventricular fibrillation/pulseless ventricular tachycardia, defibrillation performed during transportation, short time interval from receipt of call to ROSC, coronary angiography/PCI and therapeutic hypothermia performed. Of these factors, the only independent factor associated with good neurological outcome was the short time interval from receipt of the call to ROSC. Conclusions In the present study, shortening time interval from receipt of call to ROSC was the only important independent factor to achieve good neurological outcome in patients with PCAS.

Application of a Novel Technique for Clinical Evaluation of Nitric Oxide-Induced Free Radical Reactions in ICU Patients

Abstract1. We recently developed a new technique for measuring serum NO2 and NO3 levels precisely, and we examined these parameters in severely brain-injured ICU patients who could not take nutrition intestinally.2. Our results demonstrated that NO increased rapidly after stroke, trauma, and the occurrence of infection in all ICU patients. Elevation of NO2/NO3 was most pronounced 24 to 48 hr after trauma or ischemic stroke. This dysregulation of free radical elimination closely correlated with hemoglobin levels.3. In most ICU patients,with the exception of those with complications of infection, the free radical potentials were maximal at 24 to 48 hr and continued to remain high for 4 to 5 days after trauma or stroke. The level of free radical potentials was closely correlated with the severity and prognosis of critically injured patients. None with radical potential values higher than 0.4 μM survived.4.Clinically, the maintenance of hemoglobin at >12 g/dl and lower body temperature were demonstrated to be successful in the management of these free radical reactions.