Complications associated with blood alcohol concentration following injury

Chronic Binge Alcohol Administration Dysregulates Hippocampal Genes Involved in Immunity and Neurogenesis in Simian Immunodeficiency Virus-Infected Macaques

Alcohol use disorders (AUD) exacerbate neurocognitive dysfunction in Human Immunodeficiency Virus (HIV+) patients. We have shown that chronic binge alcohol (CBA) administration (13–14 g EtOH/kg/wk) prior to and during simian immunodeficiency virus (SIV) infection in rhesus macaques unmasks learning deficits in operant learning and memory tasks. The underlying mechanisms of neurocognitive alterations due to alcohol and SIV are not known. This exploratory study examined the CBA-induced differential expression of hippocampal genes in SIV-infected (CBA/SIV+; n = 2) macaques in contrast to those of sucrose administered, SIV-infected (SUC/SIV+; n = 2) macaques. Transcriptomes of hippocampal samples dissected from brains obtained at necropsy (16 months post-SIV inoculation) were analyzed to determine differentially expressed genes. MetaCore from Thomson Reuters revealed enrichment of genes involved in inflammation, immune responses, and neurodevelopment. Functional relevance of these alterations was examined in vitro by exposing murine neural progenitor cells (NPCs) to ethanol (EtOH) and HIV trans-activator of transcription (Tat) protein. EtOH impaired NPC differentiation as indicated by decreased βIII tubulin expression. These findings suggest a role for neuroinflammation and neurogenesis in CBA/SIV neuropathogenesis and warrant further investigation of their potential contribution to CBA-mediated neurobehavioral deficits.

The Legal Limit: Differences in Injury Severity Score for Vehicular Crashes

In 2013, the National Transportation Safety Board advised lawmakers in the United States to reduce the legal limit of blood alcohol content (BAC) from 0.08% to 0.05%. The purpose of this research was to evaluate the rationale for reducing the legal limit of BAC to 0.05% through analysis of the relationship between BAC and injury severity. A correlational study was conducted on patients with positive BAC involved in a motor vehicular collision. Retrospective review of 446 trauma patients (aged 18-80 years) injured in a vehicular collision routinely screened for BAC was conducted. Two groups were compared: Group 1, patients with nonzero blood alcohol concentration (n = 101); and Group 2, patients with zero blood alcohol (n = 345). Standard statistical analyses were utilized. A total of 101 patients (23%) had a detectable BAC on admission. Patients with a detectable BAC were younger (33 and 44 years) and more likely to be male (27% and 16%). There was no statistically significant association between both injury severity score (ISS) and BAC or between ISS and age. There was no significant correlation between higher BAC and a higher ISS. Positive BAC alone may not affect ISS, but the potential for risk-taking behaviors by drivers under the influence may increase injury severity.

Alcohol Intake and Reduced Mortality in Patients with Traumatic Brain Injury

BACKGROUND

The purpose of our study was to determine whether alcohol intake influences short-term mortality in patients with traumatic brain injury (TBI), using a comprehensive trauma database.

METHODS

We collected data from 7 emergency departments (EDs) between June 1, 2008 and May 31, 2010, using the same data form. Cases were included if they met the following criteria: (i) older than 15 and (ii) injuries including TBI. Demographics and outcomes were compared between patients with and without alcohol intake. We present the risk of mortality using hazard ratios and 95% confidence intervals.

RESULTS

A total of 76,596 trauma patients visited the EDs during the study period; 12,980 patients were older than 15 and had TBI. There were 4,009 (30.9%) patients in the alcohol-intake group, of whom 3,306 (82.5%) patients were male, 1,450 (36.2%) patients were moved by ambulance, and 1,218 (30.4%) patients' injuries were intentional. The most frequent injury mechanism was falling down with alcohol intake and blunt injury without alcohol intake. Mortality rate was 1.0% with alcohol intake and 2.0% without alcohol intake. After adjusting for all factors related to mortality, the hazard ratio of mortality was 0.72 in the alcohol-intake group.

CONCLUSIONS

Mortality rate due to TBI in the alcohol-intake group appears to be lower compared to that in the no-alcohol-intake group after adjusting for main confounding variables.

Alcohol impairs skeletal muscle protein synthesis and mTOR signaling in a time-dependent manner following electrically stimulated muscle contraction

Alcohol (EtOH) decreases protein synthesis and mammalian target of rapamycin (mTOR)-mediated signaling and blunts the anabolic response to growth factors in skeletal muscle. The purpose of the current investigation was to determine whether acute EtOH intoxication antagonizes the contraction-induced increase in protein synthesis and mTOR signaling in skeletal muscle. Fasted male mice were injected intraperitoneally with 3 g/kg EtOH or saline (control), and the right hindlimb was electrically stimulated (10 sets of 6 contractions). The gastrocnemius muscle complex was collected 30 min, 4 h, or 12 h after stimulation. EtOH decreased in vivo basal protein synthesis (PS) in the nonstimulated muscle compared with time-matched Controls at 30 min, 4 h, and 12 h. In Control, but not EtOH, PS was decreased 15% after 30 min. In contrast, PS was increased in Control 4 h poststimulation but remained unchanged in EtOH. Last, stimulation increased PS 10% in Control and EtOH at 12 h, even though the absolute rate remained reduced by EtOH. The stimulation-induced increase in the phosphorylation of S6K1 Thr(421)/Ser(424) (20-52%), S6K1 Thr(389) (45-57%), and its substrate rpS6 Ser(240/244) (37-72%) was blunted by EtOH at 30 min, 4 h, and 12 h. Phosphorylation of 4E-BP1 Ser(65) was also attenuated by EtOH (61%) at 4 h. Conversely, phosphorylation of extracellular signal-regulated kinase Thr(202)/Tyr(204) was increased by stimulation in Control and EtOH mice at 30 min but only in Control at 4 h. Our data indicate that acute EtOH intoxication suppresses muscle protein synthesis for at least 12 h and greatly impairs contraction-induced changes in synthesis and mTOR signaling.