Andrea Regner

Role of serum S100B as a predictive marker of fatal outcome following isolated severe head injury or multitrauma in males.

Abstract Background: Severe traumatic brain injury (TBI) is associated with a 30%–70% mortality rate. S100B has been proposed as a biomarker for indicating outcome after TBI. Nevertheless, controversy has arisen concerning the predictive value of S100B for severe TBI in the context of multitrauma. Therefore, our aim was to determine whether S100B serum levels correlate with primary outcome following isolated severe TBI or multitrauma in males. Methods: Twenty-three consecutive male patients (age 18–65years), victims of severe TBI [Glasgow Coma Scale (GCS) 3–8] (10 isolated TBI and 13 multitrauma with TBI) and a control group consisting of eight healthy volunteers were enrolled in this prospective study. Clinical outcome variables of severe TBI comprised: survival, time to intensive care unit (ICU) discharge, and neurological assessment [Glasgow Outcome Scale (GOS) at ICU discharge]. Venous blood samples were taken at admission in the ICU (study entry), 24h later, and 7days later. Serum S100B concentration was measured by an immunoluminometric assay. Results: At study entry (mean time 10.9h after injury), mean S100B concentrations were significantly increased in the patient with TBI (1.448μg/L) compared with the control group (0.037μg/L) and patients with fatal outcome had higher mean S100B (2.10μg/L) concentrations when compared with survivors (0.85μg/L). In fact, there was a significant correlation between higher initial S100B concentrations and fatal outcome (Spearmans =0.485, p=0.019). However, there was no correlation between higher S100B concentrations and the presence of multitrauma. The specificity of S100B in predicting mortality according to the cut-off of 0.79μg/L was 73% at study entry. Conclusions: Increased serum S100B levels constitute a valid predictor of unfavourable outcome in severe TBI, regardless of the presence of associated multitrauma. Clin Chem Lab Med 2006;44:1234–42.

Increased serum S100β protein concentrations following severe head injury in humans: a biochemical marker of brain death?

This study investigated S100β protein as a biochemical serum marker of brain damage in severe head injury and brain death victims. Blood samples obtained from 15 patients with severe head injury admitted to the trauma intensive care unit (ICU), five patients with a diagnosis of brain death due to hemorrhage following cerebral aneurysm rupture, and five healthy individuals were investigated. The S100β protein serum concentrations were analyzed with a immunoradiometric assay kit. The 15 patients with severe head injury were followed up for 6 months. Outcome was considered either death or recovery with ICU discharge. S100β concentrations were closely related to brain damage. Among the severe head injury victims, higher S100β concentrations were detected in those patients that progressed to death. The individuals with brain death had similar mean S100β concentrations, irrespective of its cause (either trauma or vascular rupture). S100β protein is a promising serum outcome predictor for severe head injury victims and may contribute to the early diagnosis of brain death.

Increased levels of interleukin-6, -8 and -10 are associated with fatal outcome following severe traumatic brain injury.

Abstract Background: Despite the involvement of cytokine production in neurotrauma, there is still controversy regarding cytokines levels and clinical outcome following severe traumatic brain injury (TBI). Objective: The present study was designed to investigate whether cytokine levels (of IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α) are associated with primary outcome (death or survival) after severe TBI. Methods: This prospective study enrolled 24 male patients, victims of severe TBI. Venous blood samples were taken in the Intensive Care Unit (ICU) (study entry), 24 and 48 hours later. Plasma cytokine levels were assayed by flow cytometry. Results: Severe TBI was associated with a 42% mortality rate. TBI patients had a significant increase in the levels of all cytokines measured, except for IL-1β, compared to controls. Statistically significant increases in the IL-10, -8 and -6 levels were observed in the non-survivors TBI patients compared to the survivors sub-group measured in the first sample (study entry) and in the subsequent sample (24 hours later). There were no significant differences in IL-1β, TNF-α and IL-12p70 levels between survivors and non-survivors in any time sampled. Conclusions: The findings indicate that increased IL-10, -8 and -6 levels may constitute an early predictor of unfavourable outcome in severe TBI patients.

IL-6 polymorphism associated with fatal outcome in patients with severe traumatic brain injury

Objective: The aim of this study was to test whether a functional polymorphism (-174C/G) located in the promoter region of the interleukin-6 (IL-6) gene is associated with primary short-term outcome (death or Intensive Care Unit discharge) in patients with severe traumatic brain injury (TBI). Methods: The study group consisted of 77 male patients who suffered severe TBI. The -174C/G IL-6 polymorphism was analysed by polymerase chain reaction (PCR) followed by restriction digestion. Results: Severe TBI was associated with a 44% mortality rate. The GG genotype was significantly more frequent in the survivor group than in non-surviving patients (67% vs 41%; p = 0.038); similarly, the IL-6 -174G allele was more frequent in the survivor group than in non-surviving patients (81% vs 65%; p = 0.031). Conclusion: The findings indicate that genetic variation regarding inflammatory response has significant impact on the short-term outcome for patients after acute severe TBI.

Neurochemical characterization of traumatic brain injury in humans.

Trauma is the leading cause of death in individuals between the ages of 1 and 44 years. And, in the case of severe head injury mortality can reach as high as 35-70%. Despite this fact, there has been little progress in the development of effective pharmacological agents to protect brain injured patients. To date, there is little data on the mechanisms involved in neuronal cellular insult after severe head injury, especially in humans. Glutamate acts both as a primary excitatory neurotransmitter and a potential neurotoxin within the mammalian brain. Evidence indicates that hyperactivity of the glutamate system contributes to neuronal death in brain trauma. Also, in animal models of neurotrauma, this neural injury is followed by gliosis which has been linked to the severity of brain injury. To investigate the glutamate system in brain trauma, we carried out [3H]glutamate and [3H]MK801 (a noncompetitive NMDA-receptor antagonist) binding and [3H]glutamate uptake assays in human cerebral cortex preparations obtained from severely brain injured and control victims. Additionally, to investigate gliosis following brain injury, we performed GFAP immunohistochemistry. There were no significant differences in [3H]glutamate binding (affinity or density of sites) between the control and head injured groups. In contrast, cerebral cortical [3H]MK801 binding revealed both a significant increase in the density of sites (Bmax) and a decrease in the dissociation constant (Kd) in the head injured group when compared to controls. There were no significant differences in [3H]glutamate uptake between groups. The injured brains presented an increased number of GFAP-positive astrocytes and more intense GFAP reaction in comparison to control brains. In the context of traumatic brain injury, our results encourage further investigation into compounds capable of selective modulation of NMDA receptor subtype in humans while also therapeutically manipulating glial cell responses following brain trauma.

Irinotecan/5-fluorouracil combination induces alterations in mitochondrial membrane potential and caspases on colon cancer cell lines.

The combination of irinotecan (CPT-11) and 5-fluorouracil (5-FU) is currently used in the treatment of advanced colorectal carcinoma. When compared to both agents alone, CPT-11 followed by 5-FU treatment demonstrated a synergistic effect. This observation can be related to increased in apoptosis induction after caspase activation. Several studies have demonstrated that changes in mitochondrial membrane potential occur earlier in apoptosis. In this study, we verified whether the collapse in mitochondrial membrane and the activation of caspases is responsible for increased apoptosis observed with CPT-11/5-FU treatment. Thus, HT-29 and SNU-C4 human colon carcinoma cell lines were exposed for 24 h to each drug alone, and to various combinations and treatment sequences, and assessed for colony formation, changes in the mitochondrial membrane potential, and the activities of caspase-3, -8, and -9. The CPT-11/5-FU treatment induced apoptosis in both cell lines; however, the most pronounced effect was observed in HT-29 cells. In these cells, both caspase-3 and -9 were involved in the activation of apoptosis after CPT-11/5-FU treatment. Moreover, in these cells, a reduction of 50% in mitochondrial membrane potential was observed with this treatment. On the other hand, in the SNU-C4 cell line in addition to caspase-3 and-9, caspase-8 seems to be important to apoptosis after CPT-11/5-FU treatment. Furthermore, in this cell line we did not observe alterations in mitochondrial membrane potential. In spite of the differences among the cell lines, these results indicated that the increase in apoptosis in HT-29 cells observed with CPT-11 followed by 5-FU treatment could be explained by a disruption in mitochondria membrane potential that induced caspases activation.

The Irinotecan/5-Fluorouracil Combination Induces Apoptosis and Enhances Manganese Superoxide Dismutase Activity in HT-29 Human Colon Carcinoma Cells

Background: We examined whether induction of apoptosis and Mn-superoxide dismutase (Mn-SOD) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activities were involved in the greater cytotoxicity of the irinotecan (CPT-11)/5-fluorouracil (5-FU) combination for human colon cancer cells when compared to both drugs alone. Methods: HT-29 and SNU-C4 human colon carcinoma cell lines were treated with 5-FU and CPT-11, then apoptosis was evaluated by flow cytometry and SOD activities were determined by polyacrylamide gel electrophoresis. Results: Enhanced apoptosis of HT-29 cells was observed with all treatments containing 5-FU in SNU-C4 cells; however, in HT-29 cells, apoptosis was enhanced only with the CPT-11/5-FU combination. In the SNU-C4 cell line, none of the treatments exerted a significant effect on Cu,Zn-SOD or Mn-SOD activity. However, in HT-29 cells, the CPT-11/5-FU combination enhanced Mn-SOD activity when compared to cells treated with CPT-11 alone. Nevertheless, the combined treatment did not interfere with Cu,Zn-SOD activity. Conclusion: Treatment with the CPT-11/5-FU combination may promote in HT-29 cell apoptosis by enhancing Mn-SOD activity.

Elevated Cell-Free Plasma DNA Level as an Independent Predictor of Mortality in Patients with Severe Traumatic Brain Injury

Trauma is the leading cause of death in individuals less than 45 years old worldwide, and up to 50% of trauma fatalities are because of brain injury. Prediction of outcome is one of the major problems associated with severe traumatic brain injury (TBI), and research efforts have focused on the investigation of biomarkers with prognostic value after TBI. Therefore, our aim was to investigate whether cell-free DNA concentrations correlated to short-term primary outcome (survival or death) and Glasgow Coma Scale (GCS) scores after severe TBI. A total of 188 patients with severe TBI were enrolled in this prospective study; outcome variables comprised survival and neurological assessment using the GCS at intensive care unit (ICU) discharge. Control blood samples were obtained from 25 healthy volunteers. Peripheral venous blood was collected at admission to the ICU. Plasma DNA was measured using a real-time quantitative polymerase chain reaction (PCR) assay for the β-globin gene. There was correlation between higher DNA levels and both fatal outcome and lower hospital admission GCS scores. Plasma DNA concentrations at the chosen cutoff point (≥171,381 kilogenomes-equivalents/L) predicted mortality with a specificity of 90% and a sensitivity of 43%. Logistic regression analysis showed that elevated plasma DNA levels were independently associated with death (p<0.001). In conclusion, high cell-free DNA concentration was a predictor of short-term mortality after severe TBI.

Biomarcadores prognósticos no traumatismo crânio-encefálico grave

Trauma is the leading cause of death of people from 1 to 44 years of age. Traumatic brain injury is the main determinant for mortality and morbidity caused by trauma. Outcome prediction is one of the major problems related to severe traumatic brain injury because clinical evaluation has an unreliable predictive value and complicates identification of patients with higher risk of developing secondary lesions and fatal outcome. That is why, there is considerable interest in development of biomarkers that reflect the severity of brain injury and correlate with mortality and functional outcome. Proteins S100B and neuron specific enolases are among the markers most studied for this purpose, however some studies are investigating glial fibrillary acidic protein, creatinine phospokinase, isoenzime B, myelin basic protein, plasma desoxiribonucleic acid, heat shock protein 70, von Willebrand factor, metalloproteinases and brain-derived neurotrophic factor, among others. Evidence suggests that inflammation, oxidative stress, excitotoxicity, neuroendocrine responses and apoptosis play an important role in the development of secondary lesions. Markers involved in these processes are being studied in traumatic brain injury. We reviewed these biomarkers, some of which present promising results for future clinical application.

Increased serum sFas and TNFα following isolated severe head injury in males

Objectives: Severe traumatic brain injury (TBI) is associated with a 30–70% mortality rate. Nevertheless, controversy has been raised concerning the prognostic value of biomarkers following severe TBI. Therefore, our aim was to determine whether sFas or TNFα serum levels correlate with primary outcome following isolated severe TBI. Methods: Seventeen consecutive male patients, victims of isolated severe TBI (Glasgow Coma Scale score 3–8) and a control group consisting of 6 healthy male volunteers were enrolled in this prospective study. Clinical outcome variables of severe TBI comprised: survival, time for intensive care unit (ICU) discharge, and neurological assessment by Glasgow Outcome Scale at ICU discharge. Venous blood samples were taken at admission in the ICU. Serum sFas and TNFα concentrations were measured by ELISA assays. Results: At admission in the ICU (mean time 10.2 h after injury), mean sFas and TNFα concentrations were significantly increased in the TBI (0.105 and 24.275 ρg/l, respectively) compared with the control group (0.047 and 15.475 ρg/l, respectively). However, no significant correlation was found between higher serum sFas or TNFα concentrations and fatal outcome. Conclusions: Increased serum sFas and TNFα levels following isolated severe TBI did not predict fatal outcome.