Alcohol-induced alterations on host defense after traumatic injury

Mammalian Target of Rapamycin Inhibitors and Wound Healing Complications in Kidney Transplantation: Old Myths and New Realities

Mammalian target of rapamycin inhibitors (mTOR-I) lacks nephrotoxicity, has antineoplastic effects, and reduces viral infections in kidney transplant recipients. Earlier studies reported a significant incidence of wound healing complications and lymphocele. This resulted in the uncomfortable willingness of transplant clinicians to use these agents in the immediate posttransplant period. As evidence and experience evolved over time, much useful information became available about the optimal use of these agents. Understandably, mTOR-I effects wound healing through their antiproliferative properties. However, there are a lot of other immunological and nonimmunological factors which can also contribute to wound healing complications. These risk factors include obesity, uremia, increasing age, diabetes, smoking, alcoholism, and protein-energy malnutrition. Except for age, the rest of all these risk factors are modifiable. At the same time, mycophenolic acid derivatives, steroids, and antithymocyte globulin (ATG) have also been implicated in wound healing complications. A lot has been learnt about the optimal dose of mTOR-I and their trough levels, its combinations with other immunosuppressive medications, and patients' profile, enabling clinicians to use these agents appropriately for maximum benefits. Recent randomized control trials have further increased the confidence of clinicians to use these agents in immediate posttransplant periods.

Immune response profiling in patients with traumatic injuries associated with alcohol ingestion

Traumatic injuries afflict more than 5 million people globally every year. Current and past animal research has demonstrated association among alcohol, trauma, and impaired immune function, whereas human registries have shown association between alcohol and morbidity as well as mortality. The purpose of this study is to elucidate the immune interactions with alcohol in traumatically injured patients. We prospectively enrolled 379 patients after trauma at three medical centers in the Surgical Critical Care Initiative. Plasma was analyzed using Luminex for up to 35 different cytokines. Collected samples were grouped by patients with detectable plasma alcohol levels versus those without. Univariate testing determined differences in analytes between groups. We built Bayesian belief networks with multiple minimum descriptive lengths to compare the two groups. All 379 patient samples were analyzed. Two hundred eighty-two (74.4%) patients were men, and 143 (37.7%) were White. Patients had a median intensive care unit length of stay (LOS) of 5.8 days and hospital LOS of 12 days. Using single variate analyses, eight different cytokines were differentially associated with alcohol. Cytokines IL-12 and IL-6 were important nodes in both models and IL-10 was a prominent node in the nonalcohol model. This study found select immune function differed between traumatically injured patients with measurable serum alcohol levels as compared with those without. Traumatically injured patients with positive blood alcohol content appear less able to inhibit inflammatory stress. Alcohol appears to suppress pro-inflammatory IL-12 and IL-6, whereas patients without alcohol have greater levels of anti-inflammatory IL-10 expressed at injury and may better regulate anti-inflammatory pathways. Future studies should determine the relationship with these markers with clinically oriented outcomes.

Surgical Wound Healing in the Oral Cavity: a Review

Wound healing is a fundamental survival mechanism, largely taken for granted. It consists of four intricately tuned phases: haemostasis, inflammation, proliferation and remodelling. Successful wound healing only occurs if each phase occurs in the correct sequence and timeframe. Moreover, the oral cavity serves as a unique and remarkable setting whereby wound healing takes place in a saliva-filled environment containing millions of micro-organisms. Many local and systemic factors can impair oral wound healing. This article provides an overview of the wound healing process, with a discussion of these respective local and systemic factors, along with the potential cellular and/or molecular mechanisms involved.

CPD/Clinical Relevance: On a daily basis, dentists perform procedures such as exodontia and implant placement that rely on adequate wound healing. An improved understanding of the local and systemic factors that can impair oral wound healing can help clinicians to control these factors more accurately, resulting in improved patient outcomes.

Association between alcohol use and inflammatory biomarkers over time among younger adults with HIV-The Russia ARCH Observational Study

BACKGROUND

Biomarkers of monocyte activation (soluble CD14 [sCD14]), inflammation (interleukin-6 [IL-6]), and altered coagulation (D-dimer) are associated with increased mortality risk in people with HIV. The objective of the Russia Alcohol Research Collaboration on HIV/AIDS (ARCH) study was to evaluate the association between heavy alcohol use and inflammatory biomarkers over time.

METHODS

The study sought antiretroviral therapy naive participants with HIV (n = 350) and assessed them at baseline, 12 and 24 months. Linear mixed effects models were used to determine whether heavy drinking (self-report augmented by phosphatidylethanol [PEth], an alcohol biomarker) was longitudinally associated with IL-6, sCD14 and D-dimer adjusting for potential confounders (e.g., demographics, HIV factors, comorbid conditions).

RESULTS

Participants' baseline characteristics were as follows: 71% male; mean age of 34 years; 87% self-reported hepatitis C; and 86% current smokers. Mean log10 (HIV RNA) was 4.3 copies/mL. Heavy alcohol use, based on National Institute of Alcohol Abuse and Alcoholism risky drinking criteria and PEth (versus non-heavy alcohol use) was associated with higher sCD14 (adjusted mean difference 125 ng/mL [95% CI: 42, 209]), IL-6 (ratio of means 1.35 [95% CI: 1.17, 1.55] pg/mL), and D-dimer (ratio of means 1.20 [95% CI: 1.06, 1.37] ug/mL) across the two-year follow-up.

CONCLUSION

Among HIV+ adults, current heavy alcohol use is associated with higher sCD14, IL-6 and D-dimer over time. Since these biomarkers are associated with mortality, interventions to mitigate effects of heavy drinking on these immune processes merit consideration.

Effects of binge alcohol consumption on sleep and inflammation in healthy volunteers

Objective

Alcohol is a hypnotic that modifies immune function, specifically the cytokines interferon gamma (IFN-γ) and interleukin 2 (IL-2). We evaluated the association between unscheduled napping and acute alcohol-induced augmentation of IFN-γ and IL-2 expression.

Methods

In this prospective, observational pilot study, volunteers completed questionnaires on sleep quality, alcohol use, and hangover characteristics. Actigraph recordings began three nights before and continued for four nights after study initiation. Napping was recorded by actigraphy and self-reporting. A weight-based dose of 100-proof vodka was consumed, and the blood alcohol content (BAC) and phytohemagglutinin-M stimulated cytokine level were measured before and 20 minutes, 2 hours, and 5 hours after binge consumption.

Results

Ten healthy volunteers participated (mean age, 34.4 ± 2.3 years; mean body mass index, 23.9 ± 4.6 kg/m²; 60% female). The mean 20-minute BAC was 137.7 ± 40.7 mg/dL. Seven participants took an unscheduled nap. The ex vivo IFN-γ and IL-2 levels significantly increased at all time points after binge consumption in the nappers, but not in the non-nappers.

Conclusion

Augmented IFN-γ and IL-2 levels are associated with unscheduled napping after binge alcohol consumption. Further studies are needed to clarify the associations among alcohol consumption, sleep disruption, and inflammatory mediators.

N-Acetyl Cysteine Treatment Restores Early Phase Fracture Healing in Ethanol-Fed Rats

BACKGROUND

Fracture healing in alcoholics is delayed and often associated with infections resulting in prolonged rehabilitation. It has been reported that binge drinking of alcohol increases oxidative stress and delays fracture healing in rats, which is prevented by treatment with the antioxidant n-acetyl cysteine (NAC). Oxidative stress is a significant factor in pathologies of various organs resulting from chronic alcoholism. Therefore, we hypothesize that treatment with NAC reduces oxidative stress and restores fracture healing in chronic alcoholics.

METHODS

Rats (10 months old) were pair-fed the Lieber-DeCarli ethanol (EtOH) diet or control diet for 16 weeks. A closed fracture was performed and rats allowed to recover for 72 hours. Rats were divided into 4 groups-control, control + NAC, EtOH, and EtOH + NAC-and injected intraperitoneally with 200 mg/kg of NAC daily for 3 days. Serum and bone fracture callus homogenates were collected and assayed for traditional markers of inflammation, oxidative stress, and bone regeneration.

RESULTS

The oxidative stress marker malondialdehyde (MDA) was increased in both serum and bone tissue in EtOH-fed animals compared to controls. NAC treatment significantly (p < 0.01) reduced MDA to near normal levels and dramatically increased the index of antioxidant efficacy (catalase/MDA ratio) (p < 0.01). Inflammatory markers tumor necrosis factor-α, interferon-γ, and interleukin-6 were significantly decreased in serum and callus following NAC treatment. NAC treatment reduced EtOH-induced bone resorption as evidenced by significant decreases in C-telopeptide of type-I-collagen levels (p < 0.05) and band-5 tartrate-resistant acid phosphatase levels in the tissue (p < 0.001).

CONCLUSIONS

Oxidative stress and excessive inflammation are involved in the inhibition of fracture healing by EtOH. In this study, early short-term treatment of EtOH-fed animals with the antioxidant NAC reduced oxidative stress and normalized the innate immune response to fracture in the early phase of fracture healing, thereby restoring the normal onset of bone regeneration.

Sphingosine-1-Phosphate Treatment Can Ameliorate Microvascular Leakage Caused by Combined Alcohol Intoxication and Hemorrhagic Shock

Fluid resuscitation following hemorrhagic shock is often problematic, with development of prolonged hypotension and edema. In addition, many trauma patients are also intoxicated, which generally worsens outcomes. We directly investigated how alcohol intoxication impacts hemorrhagic shock and resuscitation-induced microvascular leakage using a rat model with intravital microscopic imaging. We also tested the hypothesis that an endothelial barrier-protective bioactive lipid, sphingosine-1-phosphate (S1P), could ameliorate the microvascular leakage following alcohol intoxication plus hemorrhagic shock and resuscitation. Our results show that alcohol intoxication exacerbated hemorrhagic shock and resuscitation-induced hypotension and microvascular leakage. We next found that S1P effectively could reverse alcohol-induced endothelial barrier dysfunction using both cultured endothelial cell monolayer and in vivo models. Lastly, we observed that S1P administration ameliorated hypotension and microvascular leakage following combined alcohol intoxication and hemorrhagic shock, in a dose-related manner. These findings suggest the viability of using agonists that can improve microvascular barrier function to ameliorate trauma-induced hypotension, offering a novel therapeutic opportunity for potentially improving clinical outcomes in patients with multi-hit injuries.

Alcohol Consumption Modulates Host Defense in Rhesus Macaques by Altering Gene Expression in Circulating Leukocytes

Several lines of evidence indicate that chronic alcohol use disorder leads to increased susceptibility to several viral and bacterial infections, whereas moderate alcohol consumption decreases the incidence of colds and improves immune responses to some pathogens. In line with these observations, we recently showed that heavy ethanol intake (average blood ethanol concentrations > 80 mg/dl) suppressed, whereas moderate alcohol consumption (blood ethanol concentrations < 50 mg/dl) enhanced, T and B cell responses to modified vaccinia Ankara vaccination in a nonhuman primate model of voluntary ethanol consumption. To uncover the molecular basis for impaired immunity with heavy alcohol consumption and enhanced immune response with moderate alcohol consumption, we performed a transcriptome analysis using PBMCs isolated on day 7 post-modified vaccinia Ankara vaccination, the earliest time point at which we detected differences in T cell and Ab responses. Overall, chronic heavy alcohol consumption reduced the expression of immune genes involved in response to infection and wound healing and increased the expression of genes associated with the development of lung inflammatory disease and cancer. In contrast, chronic moderate alcohol consumption upregulated the expression of genes involved in immune response and reduced the expression of genes involved in cancer. To uncover mechanisms underlying the alterations in PBMC transcriptomes, we profiled the expression of microRNAs within the same samples. Chronic heavy ethanol consumption altered the levels of several microRNAs involved in cancer and immunity and known to regulate the expression of mRNAs differentially expressed in our data set.

Dissolution of lipids from mucus: a possible mechanism for prompt disruption of gut barrier function by alcohol

Acute and/or chronic alcohol ingestion has been shown to exacerbate the morbidity and mortality rate associated with acute mechanical and/or thermal trauma. While alcohol ingestion can affect many organs and systems, clinical and preclinical studies indicate that alcohol ingestion can cause a 'leaky gut' syndrome which in turn contributes to infection and systemic organ dysfunction. This study investigated the acute effect of alcohol on gut barrier function. Using an in vivo isolated gut sac model of naïve male rats, each individual gut sac was injected with different concentrations (0, 5, 10, 20, and 40%, v/v) of alcohol. After different times of alcohol exposure, each isolated gut segment was harvested and intestinal permeability and mucosal surface hydrophobicity (a physiologic marker of mucus barrier function) were measured as well as luminal DNA, mucus, protein and free fatty acids. The results showed that alcohol caused dose-dependent and time-dependent increases in gut permeability and decreases in mucosal surface hydrophobicity, with significant changes to be observed 5 min after treatment with 10% alcohol. In addition, it is further found that these changes in permeability and hydrophobicity are more closely associated with increased intestinal luminal free fatty acids levels but not protein or DNA levels. These results suggest that alcohol may cause loss of gut barrier function by extracting and dissolving lipids from the mucus with a resultant decrease in mucosal surface hydrophobicity, which is a critical component of gut barrier function.

Blood alcohol content, injury severity, and adult respiratory distress syndrome

BACKGROUND

Elevated blood alcohol content (BAC) is a risk factor for injury. Associations of BAC with adult respiratory distress syndrome (ARDS) have not been conclusively established.We evaluated the association of a BAC greater than 0 mg/dL with the intermediate outcomes, Injury Severity Score (ISS) and Glasgow Coma Scale (GCS) score, and their association with ARDS development.

METHODS

This is an observational retrospective cohort study of 26,305 primary trauma admissions to a statewide referral trauma center from July 11, 2003, to October 31, 2011. Logistic regression was performed to assess the relationship between admission BAC, ISS, GCS score, and ARDS development within 5 days of admission.

RESULTS

The case rate for ARDS was 5.5% (1,447). BAC greater than 0 mg/dL was associated with ARDS development in adjusted analysis (odds ratio, 1.50; 95% confidence interval [CI], 1.33-1.71; p < 0.001). High ISS (≥16) had a stronger association with ARDS development (odds ratio, 17.99; 95% CI, 15.51-20.86), as did low GCS score (≤8) (odds ratio, 8.77; 95% CI, 7.64-10.07; p < 0.001). Patients with low GCS score and high ISS had the most frequent ARDS (33.6%) and the highest case-fatality rate without ARDS (24.7%).

CONCLUSION

Elevated BAC is associated with ARDS development. In the analysis of alcohol exposure, ISS and GCS score occur after alcohol ingestion, making them intermediate outcomes. ISS and GCS score were strong predictors of ARDS and may be useful to identify at-risk patients. Elevated BAC may increase the frequency of the ARDS through influence on injury severity or independent molecular mechanisms, which can be discriminated only in experimental models.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Acute alcohol intoxication prolongs neuroinflammation without exacerbating neurobehavioral dysfunction following mild traumatic brain injury

Traumatic brain injury (TBI) represents a leading cause of death and disability among young persons with ∼1.7 million reported cases in the United States annually. Although acute alcohol intoxication (AAI) is frequently present at the time of TBI, conflicting animal and clinical reports have failed to establish whether AAI significantly impacts short-term outcomes after TBI. The objective of this study was to determine whether AAI at the time of TBI aggravates neurobehavioral outcomes and neuroinflammatory sequelae post-TBI. Adult male Sprague-Dawley rats were surgically instrumented with gastric and vascular catheters before a left lateral craniotomy. After recovery, rats received either a primed constant intragastric alcohol infusion (2.5 g/kg+0.3 g/kg/h for 15 h) or isocaloric/isovolumic dextrose infusion followed by a lateral fluid percussion TBI (∼1.4 J, ∼30 ms). TBI induced apnea and a delay in righting reflex. AAI at the time of injury increased the TBI induced delay in righting reflex without altering apnea duration. Neurological and behavioral dysfunction was observed at 6 h and 24 h post-TBI, and this was not exacerbated by AAI. TBI induced a transient upregulation of cortical interleukin (IL)-6 and monocyte chemotactic protein (MCP)-1 mRNA expression at 6 h, which was resolved at 24 h. AAI did not modulate the inflammatory response at 6 h but prevented resolution of inflammation (IL-1, IL-6, tumor necrosis factor-α, and MCP-1 expression) at 24 h post-TBI. AAI at the time of TBI did not delay the recovery of neurological and neurobehavioral function but prevented the resolution of neuroinflammation post-TBI.

Drug and alcohol use complicate traumatic peripheral vascular injury

BACKGROUND

Drug and alcohol use complicate the presentation and management of traumatic injuries. Impaired hemodynamic recovery and host defense in substance users also predispose these patients to worse outcomes after trauma. We hypothesized that substance abuse, particularly when drugs and alcohol are combined, complicates the presentation, management, and patient outcomes following isolated traumatic peripheral vascular injury.

METHODS

This is a retrospective analysis of patients admitted with isolated peripheral vascular injury to our Level 1 trauma center between 2006 and 2012. Demographics, presentation, substance use, resuscitation, operative management, intensive care needs, and length of hospital stay were analyzed.

RESULTS

From 257 patients admitted, 158 patients experienced isolated peripheral vascular injury. Patients were subdivided by blood alcohol level (BAL) and urinary toxicology (utox) screens; negative BAL/negative utox (nonintoxicated, n = 90), negative BAL/positive utox (drug users, n = 27), positive BAL/negative utox (alcohol users, n = 22), and positive BAL/positive utox (polysubstance users, n = 19). Compared with nonintoxicated patients, more polysubstance users experienced lower-extremity injury (79% vs. 47%) and presented more often than alcohol users with proximal injury (83% vs. 45%), lower-extremity injury (79% vs. 36%), and as a result of assault (68.4% vs. 31.8%). Polysubstance users required greater resuscitation, more operations, and more frequently experienced complications than any other cohort. Subsequently, these patients had a greater need for intensive care management and longer hospital stay than nonintoxicated and alcohol users. Moreover, using multivariate logistic regression analysis, we found that polysubstance use, alcohol use, and lower-extremity injury are each independent risk factors for infectious complications.

CONCLUSION

Our data show that polysubstance users with isolated peripheral vascular injury experience more proximal and lower-extremity injuries, require greater resuscitation, and undergo more operations compared with nonintoxicated patients. Treatment of these patients is more frequently complicated by infection, vascular complications, and increased hospital length of stay.

Age and gender differences in substance screening may underestimate injury severity: a study of 9793 patients at level 1 trauma center from 2006 to 2010

BACKGROUND

Although the relationship between psychoactive substance use and injury is known, evidence remains conflicting on the impact of substance use on clinical outcomes after injury. We hypothesized that preinjury substance use would negatively impact clinical outcomes.

METHODS

National Trauma Registry American College of Surgeons identified patients (n = 9793) presenting to Duke Hospital from 2006 to 2010. Logistic regression models assessed potential predictors of receiving substance screening, mortality, length of stay, ventilator requirement, intensive care admission, or emergency department disposition.

RESULTS

Forty-seven percent (4607/9793) of patients received blood alcohol screen (BAS) and 31% (3017/9793) received urine drug screen (UDS). Men were more likely to receive both BASs (P < 0.001) and UDSs (P = 0.001) than women after controlling for potential confounders. There was no significant difference between men and women over the legal limit for alcohol (OLLA; 27.2%, 95% confidence interval [CI]: 25.7%-28.8% versus 24.8%, 95% CI: 22.3%-27.5%). Similarly, younger patients more likely received both BASs (P < 0.001) and UDSs (P < 0.001) compared with older patients. The proportion of patients aged ≤45 y OLLA (26.5 %, 95% CI: 24.9%-28.2%) was similar to those aged >45 y OLLA (26.8%, 95% CI: 24.5%-29.3%). After controlling for potential confounders neither alcohol, nor tetrahydrocannabinol, nor cocaine was predictive of mortality, ventilator requirement, length of stay, or emergency department disposition, but a higher alcohol level (P = 0.0174) predicted intensive care admission.

CONCLUSIONS

Females and those aged >45 y are less likely to receive BASs and UDSs. Differential screening that is biased may place patients at risk for receiving inadequate care.

Heavy ethanol intoxication increases proinflammatory cytokines and aggravates hemorrhagic shock-induced organ damage in rats

Hemorrhagic shock (HS) following acute alcohol intoxication can increase proinflammatory cytokine production and induce marked immunosuppression. We investigated the effects of ethanol on physiopathology and cytokine levels following HS in acutely alcohol-intoxicated rats. Rats received an intravenous injection of 5 g/kg ethanol over 3 h followed by HS induced by withdrawal of 40% of total blood volume from a femoral arterial catheter over 30 min. Mean arterial pressure (MAP) and heart rate (HR) were monitored continuously for 48 h after the start of blood withdrawal. Biochemical parameters, including hemoglobin, ethanol, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), blood urea nitrogen (BUN), creatinine (Cre), lactic dehydrogenase (LDH), and creatine phosphokinase (CPK), were measured at 30 min before induction of HS and 0, 1, 3, 6, 9, 12, 18, 24, and 48 h after HS. Serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were measured at 1 and 12 h after HS. The liver, kidneys, and lungs were removed for pathology at 48 h later. HS significantly increased HR, blood GOT, GPT, BUN, Cre, LDH, CPK, TNF-α, and IL-6 levels and decreased hemoglobin and MAP in rats. Acute ethanol intoxication further increased serum levels of GOT, GPT, BUN, Cre, LDH, CPK, TNF-α and IL-6 elevation following HS. Acutely intoxicated rats exacerbated the histopathologic changes in the liver, kidneys, and lungs following HS.

Angiotensin (1-7) contributes to nitric oxide tonic inhibition of vasopressin release during hemorrhagic shock in acute ethanol intoxicated rodents

AIMS

Acute ethanol intoxication (AEI) attenuates the arginine vasopressin (AVP) response to hemorrhage leading to impaired hemodynamic counter-regulation and accentuated hemodynamic stability. Previously we identified that the ethanol-induced impairment of circulating AVP concentrations in response to hemorrhage was the result of augmented central nitric oxide (NO) inhibition. The aim of the current study was to examine the mechanisms underlying ethanol-induced up-regulation of paraventricular nucleus (PVN) NO concentration. Angiotensin (ANG) (1-7) is an important mediator of NO production through activation of the Mas receptor. We hypothesized that Mas receptor inhibition would decrease central NO concentration and thus restore the rise in circulating AVP levels during hemorrhagic shock in AEI rats.

MAIN METHODS

Conscious male Sprague-Dawley rats (300-325 g) received a 15 h intra-gastric infusion of ethanol (2.5 g/kg+300 mg/kg/h) or dextrose prior to a fixed-pressure (~40 mm Hg) 60 min hemorrhage. The Mas receptor antagonist A-779 was injected through an intracerebroventricular (ICV) cannula 15 min prior to hemorrhage.

KEY FINDINGS

PVN NOS activity and NO were significantly higher in AEI compared to DEX-treated controls at the completion of hemorrhage. ICV A-779 administration decreased NOS activity and NO concentration, partially restoring the rise in circulating AVP level at completion of hemorrhage in AEI rats.

SIGNIFICANCE

These results suggest that Mas receptor activation contributes to the NO-mediated inhibitory tone of AVP release in the ethanol-intoxicated hemorrhaged host.

Liver cirrhosis but not alcohol abuse is associated with impaired outcome in trauma patients - a retrospective, multicentre study

INTRODUCTION

Liver cirrhosis has been shown to be associated with impaired outcome in patients who underwent elective surgery. We therefore investigated the impact of alcohol abuse and subsequent liver cirrhosis on outcome in multiple trauma patients.

MATERIALS AND METHODS

Using the multi-centre population-based Trauma Registry of the German Society for Trauma Surgery, we retrospectively compared outcome in patients (ISS ≥ 9, ≥ 18) with pre-existing alcohol abuse and liver cirrhosis with healthy trauma victims in univariate and matched-pair analysis. Means were compared using Student's t-test and analysis of variance (ANOVA) and categorical variables using χ(2) (p<0.05=significant).

RESULTS

Overall 13,527 patients met the inclusion criteria and were, thus, analyzed. 713 (5.3%) patients had a documented alcohol abuse and 91 (0.7%) suffered from liver cirrhosis. Patients abusing alcohol and suffering from cirrhosis differed from controls regarding injury pattern, age and outcome. More specific, liver cirrhotic patients showed significantly higher in-hospital mortality than predicted (35% vs. predicted 19%) and increased single- and multi-organ failure rates. While alcohol abuse increased organ failure rates as well this did not affect in-hospital mortality.

CONCLUSIONS

Patients suffering from liver cirrhosis presented impaired outcome after multiple injuries. Pre-existing condition such as cirrhosis should be implemented in trauma scores to assess the individual mortality risk profile.

Mesenchymal stem cells facilitate fracture repair in an alcohol-induced impaired healing model

OBJECTIVES

Clinical studies have shown alcohol to be a risk factor for traumatic orthopaedic injuries and for nonunion. Data from animal studies suggest that alcohol exposure inhibits fracture healing. This report presents a novel rodent model of impaired fracture healing caused by repeated alcohol exposure. Using this model, we examined the regenerative effects of an intravenously administered population of isolated and expanded mesenchymal stem cells (MSCs) on fracture healing.

METHODS

Bone marrow-derived MSC were isolated from transgenic green fluorescent protein C57BL/6 mice, and culture expanded using a lineage depletion protocol. Adult wild-type C57BL/6 mice were subjected to a 2-week binge alcohol exposure paradigm (3 days during which they received daily intraperitoneal injections of a 20% alcohol/saline solution followed by a 4-day rest period and another binge cycle for 3 consecutive days). At completion of the second binge cycle, mice were subjected to a mid-shaft tibia fracture while intoxicated. Twenty-four hours after the fracture, animals were administered an intravenous transplant of green fluorescent protein-labeled MSC. Two weeks after the fracture, animals were euthanized and injured tibiae were collected and subjected to biomechanical, histologic, and microcomputed tomography analysis.

RESULTS

Pre-injury binge alcohol exposure resulted in a significant impairment in biomechanical strength and decrease in callus volume. MSC transplants restored both fracture callus volume (P < 0.05) and biomechanical strength (P < 0.05) in animals with alcohol-impaired healing. In vivo imaging demonstrated a time-dependent MSC migration to the fracture site.

CONCLUSIONS

These data suggest that a 2-week binge alcohol exposure significantly impairs fracture healing in a murine tibia fracture model. Intravenously administered MSC were capable of specifically homing to the fracture site and of normalizing biomechanical, histologic, and microcomputed tomography parameters of healing in animals exposed to alcohol. Understanding MSC recruitment patterns and functional contributions to fracture repair may lead to their use in patients with impaired fracture healing and nonunion.

Acute alcohol intoxication reduces mortality, inflammatory responses and hepatic injury after haemorrhage and resuscitation in vivo

BACKGROUND AND PURPOSE

Haemorrhagic shock and resuscitation (H/R) induces hepatic injury, strong inflammatory changes and death. Alcohol intoxication is assumed to worsen pathophysiological derangements after H/R. Here, we studied the effects of acute alcohol intoxication on survival, liver injury and inflammation after H/R, in rats.

EXPERIMENTAL APPROACH

Rats were given a single oral dose of ethanol (5 g·kg(-1) , 30%) or saline (control), 12 h before they were haemorrhaged for 60 min and resuscitated (H/R). Sham groups received the same procedures without H/R. Measurements were made 2, 24 and 72 h after resuscitation. Survival was assessed 72 h after H/R.

KEY RESULTS

Ethanol increased survival after H/R three-fold and also induced fatty changes in the liver. H/R-induced liver injury was amplified by ethanol at 2 h but inhibited 24 h after H/R. Elevated serum IL-6 levels as well as hepatic IL-6 and TNF-α gene expression 2 h after H/R were reduced by ethanol. Ethanol enhanced serum IL-1β at 2 h, but did not affect increased hepatic IL-1β expression at 72 h after H/R. Local inflammatory markers, hepatic infiltration with polymorphonuclear leukocytes and intercellular adhesion molecule 1 expression decreased after ethanol compared with saline, following H/R. Ethanol reduced H/R-induced IκBα activation 2 h after H/R, and NF-κB-dependent gene expression of MMP9.

CONCLUSIONS AND IMPLICATIONS

Ethanol reduced H/R-induced mortality at 72 h, accompanied by a suppression of proinflammatory changes after H/R in ethanol-treated animals. Binge-like ethanol exposure modulated the inflammatory response after H/R, an effect that was associated with NF-κB activity.

Acute ethanol intoxication and the trauma patient: hemodynamic pitfalls

Many trauma patients are acutely intoxicated with alcohol. Animal studies have demonstrated that acute alcohol intoxication inhibits the normal release of epinephrine, norepinephrine, and vasopressin in response to acute hemorrhage. Ethanol also increases nitric oxide release and inhibits antidiuretic hormone secretion. This article studies the effects of alcohol intoxication (measured by blood alcohol level, BAL) on the presentation and resuscitation of trauma patients with blunt hepatic injuries. A retrospective registry and chart review was conducted of all patients who presented with blunt liver injuries at an ACS-verified, level I trauma center. Data collected included admission BAL, systolic blood pressure, hematocrit, International Normalized Ratio (INR), liver injury grade, Injury Severity Score (ISS), intravenous fluid and blood product requirements, base deficit, and mortality. From September 2002 to May 2008, 723 patients were admitted with blunt hepatic injuries. Admission BAL was obtained in 569 patients, with 149 having levels >0.08%. Intoxicated patients were more likely to be hypotensive on admission (p = 0.01) despite a lower liver injury grade and no significant difference in ISS. There was no significant difference in the percent of intoxicated patients requiring blood transfusion. However, when blood was given, intoxicated patients required significantly more units of packed red blood cells (PRBC) than their nonintoxicated counterparts (p = 0.01). Intoxicated patients also required more intravenous fluid during their resuscitation (p = 0.002). Alcohol intoxication may impair the ability of blunt trauma patients to compensate for acute blood loss, making them more likely to be hypotensive on admission and increasing their PRBC and intravenous fluid requirements. All trauma patients should have BAL drawn upon admission and their resuscitation should be performed with an understanding of the physiologic alterations associated with acute alcohol intoxication.

Antioxidant therapy attenuates deficient bone fracture repair associated with binge alcohol exposure

OBJECTIVES

Alcohol consumption is a known risk factor for traumatic injuries of all types and has been shown to produce detrimental effects on bone metabolism. Although the mechanisms responsible for these detrimental effects are not well characterized, oxidative stress from alcohol exposure appears to play a central role. This study was designed to examine the effect of a short-term binge alcohol consumption pattern on fracture repair and the effect of an antioxidant, N-acetylcysteine, on fracture healing after binge alcohol consumption.

METHODS

One hundred forty-four adult male Sprague-Dawley rats underwent unilateral closed femur fracture after injection of either saline or alcohol to simulate a binge alcohol cycle. Animals in the antioxidant treatment group received daily N-acetylcysteine after fracture. Femurs were harvested at 1, 2, 4, and 6 weeks after injury and underwent biomechanical testing and histologic analysis.

RESULTS

Binge alcohol administration was associated with significant decreases in biomechanical strength at 1- and 2-week time points with a trend toward decreased strength at 4- and 6-week time points as well. Alcohol-treated animals had less cartilage component within the fracture callus and healed primarily by intramembranous ossification. Administration of N-acetylcysteine in alcohol-treated animals improved biomechanical strength to levels comparable to the control animals and was associated with increased endochondral ossification.

CONCLUSIONS

Our results indicate that binge alcohol alters the quality of fracture healing after a traumatic injury and that concurrent administration of an antioxidant is able to reverse these effects.

Operating characteristics of carbohydrate-deficient transferrin (CDT) for identifying unhealthy alcohol use in adults with HIV infection

Unhealthy alcohol use (the spectrum of risky use through dependence) is common in HIV-infected persons, yet it can interfere with HIV medication adherence, may lower CD4 cell count, and can cause hepatic injury. Carbohydrate-deficient transferrin (CDT), often measured as %CDT, can detect heavy drinking but whether it does in people with HIV is not well established. We evaluated the operating characteristics of %CDT in HIV-infected adults using cross-sectional data from 300 HIV-infected adults with current or past alcohol problems. Past 30-day alcohol consumption was determined using the Timeline Followback (TLFB), a validated structured recall questionnaire, as the reference standard. Sensitivity and specificity of %CDT (at manufacturer's cut-off point of 2.6%) for detecting both "at-risk" (≥4 drinks in a day or >7 drinks per week for women, ≥5 drinks in a day or >14 per week for men) and "heavy" drinking (≥4 drinks in a day for women, ≥5 drinks in a day for men on at least seven days) were calculated. Receiver operating characteristic (ROC) curves were estimated to summarize the diagnostic ability of %CDT for distinguishing "at risk" and "heavy" levels of drinking. Exploratory analyses that stratified by gender and viral hepatitis infection were performed. Of 300 subjects, 103 reported current consumption at "at-risk" amounts, and 47 reported "heavy" amounts. For "at-risk" drinking, sensitivity of %CDT was 28% (95% confidence interval (CI) 19%, 37%), specificity 90% (95% CI 86%, 94%); area under the ROC curve (AUC) was 0.59. For "heavy" drinking, sensitivity was 36% (95% CI 22%, 50%), specificity 88% (95% CI 84%, 92%); AUC was 0.60. Sensitivity appeared lower among women and those with viral hepatitis; specificity was similar across subgroups. Among HIV-infected adults, %CDT testing yielded good specificity, but poor sensitivity for detecting "at-risk" and "heavy" alcohol consumption, limiting its clinical utility for detecting unhealthy alcohol use in this population.

Binge alcohol exposure modulates rodent expression of biomarkers of the immunoinflammatory response to orthopaedic trauma

BACKGROUND

Alcohol is a known modulator of the immune system and host-defense response. Alcohol abuse is common in trauma patients, although the influence of alcohol intoxication on the inflammatory response following major orthopaedic injury remains unknown. The aim of this investigation was to examine the influence of binge alcohol exposure on biomarkers of the systemic inflammatory response following bilateral traumatic femoral fracture in a rodent model.

METHODS

Ninety-two Sprague-Dawley rats were administered intraperitoneal injections of either saline solution or alcohol for three days. These animals then underwent a sham procedure or bilateral femoral intramedullary pinning and mid-diaphyseal closed fracture via blunt guillotine. The animals were killed at specific time points after the injury. Serum and lung tissue were collected, and twenty-five inflammatory markers were analyzed by immunoassay. Histological sections of lung tissue were evaluated by a board-certified pathologist.

RESULTS

Bilateral femoral fracture significantly (p < 0.05) increased multiple serum biomarkers of inflammation. Binge alcohol treatment prior to injury significantly suppressed the increase in serum levels of interleukin (IL)-6, white blood cells, IL-2, IL-10, and C-reactive protein after the fracture. However, alcohol-treated animals were found to have increased pulmonary levels of IL-6, IL-1β, IL-2, and macrophage inflammatory protein-1α following bilateral femoral fracture. In addition, lung tissue harvested following alcohol treatment and injury demonstrated increased pathologic changes, including parenchymal, alveolar, and peribronchial leukocyte infiltration and significantly elevated pulmonary wet-to-dry ratio, indicative of pulmonary edema.

CONCLUSIONS

Our results indicate that acute alcohol intake prior to bilateral femoral fracture with fixation in rats modulates the inflammatory response after injury in a tissue-dependent manner. Although serum biomarkers of inflammation were suppressed in alcohol-treated animals following injury, several measures of pulmonary inflammation including cytokine levels, histological changes, and findings of pulmonary edema were significantly increased following fracture with the presence of alcohol.

Treatment course and outcomes following drug and alcohol-related traumatic injuries

Background

Alcohol and drug use is known to be a major factor affecting the incidence of traumatic injury. However, the ways in which immediate pre-injury substance use affects patients' clinical care and outcomes remains unclear. The goal of the present study is to determine the associations between pre-injury use of alcohol or drugs and patient injury severity, hospital course, and clinical outcome.

Materials and methods

This study used more than 200,000 records from the National Trauma Data Bank (NTDB), which is the largest trauma registry in the United States. Incidents in the NTDB were placed into one of four classes: alcohol related, drug related, alcohol-and-drug related, and substance negative. Logistic regression models were used to determine comorbid conditions or treatment complications that were significantly associated with pre-injury substance use. Hospital charges were associated with the presence or absence of drugs and alcohol, and patient outcomes were assessed using discharge disposition as delimited by the NTDB.

Results

The rates of complications arising during treatment were 8.3, 10.9, 9.9 and 8.6 per one hundred incidents in the alcohol related, drug related, alcohol-and-drug related, and substance-negative classes, respectively. Regression models suggested that pre-injury alcohol use is associated with a 15% higher risk of infection, whereas pre-injury drug use is associated with a 30% higher risk of infection. Pre-injury substance use did not appear to significantly impact clinical outcomes following treatment for traumatic injury, however.

Conclusion

This study suggests that pre-injury drug use is associated with a significantly higher complication rate. In particular, infection during hospitalization is a significant risk for both alcohol and drug related trauma visits, and drug-related trauma incidents are associated with increased risk for additional circulatory complications. Although drug and alcohol related trauma incidents are not associated with appreciably worse clinical outcomes, patients experiencing such complications are associated with significantly greater length of stay and higher hospitalization costs. Therefore significant benefits to trauma patients could be gained with enhanced surveillance for pre-injury substance use upon admission to the ED, and closer monitoring for infection or circulatory complications during their period of hospitalization.

Factors affecting wound healing

Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds.

A recent perspective on alcohol, immunity, and host defense

BACKGROUND

Multiple line of clinical and experimental evidence demonstrates that both acute, moderate, and chronic, excessive alcohol use result in various abnormalities in the functions of the immune system.

METHODS

Medline and PubMed databases were used to identify published reports with particular interest in the period of 2000-2008 in the subject of alcohol use, infection, inflammation, innate, and adaptive immunity.

RESULTS

This review article summarizes recent findings relevant to acute or chronic alcohol use-induced immunomodulation and its consequences on host defense against microbial pathogens and tissue injury. Studies with in vivo and in vitro alcohol administration are both discussed. The effects of alcohol on lung infections, trauma and burn injury, liver, pancreas, and cardiovascular diseases are evaluated with respect to the role of immune cells. Specific changes in innate immune response and abnormalities in adaptive immunity caused by alcohol intake are detailed.

CONCLUSION

Altered inflammatory cell and adaptive immune responses after alcohol consumption result in increased incidence and poor outcome of infections and other organ-specific immune-mediated effects.