Stored whole blood transfusion initiates serum amyloid A activation monitored by real-time dynamic imaging.

BACKGROUND: Transfusion of stored whole blood (SWB) to resuscitate severe traumatic haemorrhage patients in military operations and civilian emergency centres is being increasingly used in routine practice. It has been well established that transfusion of red blood cells (RBCs) after prolonged storage has harmful effects, mainly mediated by inflammation. Whether the side effects of inflammation are brought about by SWB transfusion remains unclear. MATERIALS AND METHODS: A hepatocyte SAA (serum amyloid A) specific reporter mouse that facilitated non-invasive imaging of hepatocyte SAA expression was used to evaluate acute inflammation and acute-phase reaction after the transfusion of SWB or components separated from end-storage whole blood. The whole blood of C57BL/6 donor mouse was used to model an allogeneic transfusion to BALB/c recipient mouse. RESULTS: End-storage whole blood (14 days of storage) transfusion induced the most significant SAA expression, while 10-day storage resulted in a much weaker signal compared to their fresh and 5-day storage counterparts. RBCs rather than white blood cells and plasma-containing platelets are thought to be responsible for the systemic inflammatory and SAA activation during end-storage whole blood transfusion. Circulatory and hepatic pro-inflammatory cytokines secreted by M1-polarised macrophage initiated the SAA expression in hepatocytes through nuclear transcription factor NF-κB. DISCUSSION: Storage lesions will also occur during the storage of whole blood, which is related to the change in RBCs with prolonged storage. The side effect induced by systemic inflammation and acute-phase reaction should be considered before resuscitation with long-term storage whole blood transfusion.

Multi-view radiomics and dosiomics analysis with machine learning for predicting acute-phase weight loss in lung cancer patients treated with radiotherapy.

We propose a multi-view data analysis approach using radiomics and dosiomics (R&D) texture features for predicting acute-phase weight loss (WL) in lung cancer radiotherapy. Baseline weight of 388 patients who underwent intensity modulated radiation therapy (IMRT) was measured between one month prior to and one week after the start of IMRT. Weight change between one week and two months after the commencement of IMRT was analyzed, and dichotomized at 5% WL. Each patient had a planning CT and contours of gross tumor volume (GTV) and esophagus (ESO). A total of 355 features including clinical parameter (CP), GTV and ESO (GTV&ESO) dose-volume histogram (DVH), GTV radiomics, and GTV&ESO dosiomics features were extracted. R&D features were categorized as first- (L1), second- (L2), higher-order (L3) statistics, and three combined groups, L1 + L2, L2 + L3 and L1 + L2 + L3. Multi-view texture analysis was performed to identify optimal R&D input features. In the training set (194 earlier patients), feature selection was performed using Boruta algorithm followed by collinearity removal based on variance inflation factor. Machine-learning models were developed using Laplacian kernel support vector machine (lpSVM), deep neural network (DNN) and their averaged ensemble classifiers. Prediction performance was tested on an independent test set (194 more recent patients), and compared among seven different input conditions: CP-only, DVH-only, R&D-only, DVH + CP, R&D + CP, R&D + DVH and R&D + DVH + CP. Combined GTV L1 + L2 + L3 radiomics and GTV&ESO L3 dosiomics were identified as optimal input features, which achieved the best performance with an ensemble classifier (AUC = 0.710), having statistically significantly higher predictability compared with DVH and/or CP features (p < 0.05). When this performance was compared to that with full R&D-only features which reflect traditional single-view data, there was a statistically significant difference (p < 0.05). Using optimized multi-view R&D input features is beneficial for predicting early WL in lung cancer radiotherapy, leading to improved performance compared to using conventional DVH and/or CP features.

Acute Phase Response in Critically Ill Elderly Burn Patients.

OBJECTIVES: Survival of elderly burn patients remains unacceptably poor. The acute phase, defined as the first 96 hours after burn, includes the resuscitation period and influences subsequent outcomes and survival. The aim of this study was to determine if the acute phase response post burn injury is significantly different in elderly patients compared with adult patients and to identify elements contributing to adverse outcomes. DESIGN: Cohort study. SETTING: Tertiary burn center. PATIENTS: Adult (< 65 yr old) and elderly (≥ 65 yr old) patients with an acute burn injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included all patients with an acute burn injury greater than or equal to 20% total body surface area to our burn center from 2011 to 2016. Clinical and laboratory measures during the acute phase were compared between adult and elderly patients. Outcomes included clinical hemodynamic measurements, organ biomarkers, volume of fluid resuscitation, cardiac agents, and the inflammatory cytokine response in plasma. Data were analyzed using the Student t test, Mann-Whitney U test, and Fisher exact test. A total of 149 patients were included, with 126 adults and 23 elderly. Injury severity was not significantly different among adult and elderly patients. Elderly had significantly lower heart rates (p < 0.05), cardiac index (p < 0.05), mean arterial pressure (p < 0.05), PaO2/FIO2 (p < 0.05), and pH (p < 0.05), along with higher lactate (p < 0.05). Organ biomarkers, particularly creatinine and blood urea nitrogen, showed distinct differences between adults and elderly (p < 0.05). Elderly had significantly lower levels of interleukin-6, monocyte chemotactic protein-1, monocyte chemotactic protein-3, and granulocyte-colony stimulating factor during the acute phase (p < 0.05). Overall mortality was significantly higher in elderly patients (5% vs 52%; p < 0.0001). CONCLUSIONS: Response to the burn injury during the acute phase response after burn is substantially different between elderly and adult burn patients and is characterized by cardiac depression and hypoinflammation.

Outcomes with newly proposed classification of acute respiratory deterioration in idiopathic pulmonary fibrosis.

BACKGROUND: Respiratory-related hospitalization, in particular acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF), is common and associated with increasing mortality in patients with IPF. We aimed to evaluate the implications of a newly proposed framework of acute respiratory deterioration (ARD) and AE-IPF in hospitalized patients. METHODS: Using the data of an IPF cohort consisting of 225 consecutive patients, we retrospectively studied first hospitalizations from January 2008 to December 2017. We analysed the demographics and 90-day mortality of patients with AE-IPF and those with parenchymal cause of ARD other than AE. RESULTS: Among 122 patients with first hospitalization for ARD, 35 patients were diagnosed with AE-IPF, including 11 patients with triggered AE. Parenchymal cause of ARD other than AE was diagnosed in 71 patients, and extra-parenchymal cause in 16 patients. Almost all hospitalized patients (93%) underwent chest CT, and 83% of patients with AE-IPF underwent bronchoalveolar lavage. There was a significant difference in the anti-inflammatory therapy between the AE-IPF group and parenchymal cause of ARD other than AE group (p < 0.001). AE-IPF was independently associated with poor survival in multivariate Cox proportional regression analysis. CONCLUSIONS: AE-IPF accounted for about 30% of first hospitalizations for ARD, and differentiation between AE-IPF and the other categories in ARD is important from a therapeutic and a prognostic point of view.

Acute tissue reactions, inner segment pathology, and effects of the antioxidant α1-microglobulin in an in vitro model of retinal detachment.

The purpose of this study was to explore acute tissue reactions, ultrastructural photoreceptor morphology with emphasis on inner segments, and the effect of antioxidant treatment in an in vitro model of rhegmatogenous retinal detachment (RRD). A previously described method of RRD simulation was used with adult retinal porcine explants kept free-floating in culture medium with or without treatment with the radical scavenger α1-microglobulin (A1M). Explants were examined at 5 time points from 1 to 24 h using transmission electron microscopy as well as quantitative real-time PCR (RT-PCR) to quantify gene expression of the cell stress marker heat shock protein 70 (Hsp70) and oxidative stress marker heme oxygenase (HO-1). The culture medium level of the cell damage marker lactate dehydrogenase (LDH) and oxidative stress DNA damage marker 8-Oxo-2'-deoxyguanosine (8-OHdG) was also assessed at each time point. We found that the levels of Hsp70 and LDH rapidly increased in both groups, and at 3 and 6 h, Hsp70 was significantly higher in A1M treated retinas. At 24 h, Hsp70 and LDH, as well as 8-OHdG were significantly lower compared with controls, whereas the tissue level of HO-1 was significantly higher. Progressive ultrastructural photoreceptor changes were seen in untreated control explants from 1 h and onwards including outer segment shortening and loss, disruption of organelles within the inner segments and loss of perikarya in the outer nuclear layer. Inner segment pathology was more rapid and extensive in rods compared with in cones. In A1M treated counterparts, damage to rod inner segment mitochondria was significantly higher after 1 h of culture, but after this time, no statistical difference was found. At 24 h, cone inner segment mitochondrial disruption was significantly higher in control retinas and the number of surviving perikarya lower. From our results, we conclude that retinal explants elicit acute cell stress reactions when placed in culture without physical support simulating a detached retina floating in the vitreous space. Photoreceptors rapidly display degenerative changes including extensive damage to inner segment mitochondria indicating loss of energy transduction as an early key event. A1M increases initial mitochondrial stress in the rods, however, subsequent pathology is attenuated by the treatment, highlighting the dynamics of protective as well as disruptive oxidative stress reactions in the detached retina.

Adrenal crisis after first infusion of zoledronic acid: a case report.

Patients with Addison's disease are at greater risk of having reduced bone mineral density and hip fractures and are thus more likely to receive a bisphosphonate than their peers. Potent intravenous bisphosphonates could provoke an acute phase reaction. An 80-year-old female with Addison's disease received her first infusion of zoledronic acid for osteoporosis at our outpatient clinic around noon. Despite doubling her usual afternoon hydrocortisone dose, she became feverish, nauseous, extremely weak, and hypotensive over the night. When transported to the nearest general hospital the next morning, the patient was found to have signs of hypovolemic shock and she was admitted to the ICU. Crystalloid infusion, followed by dobutamine and norepinephrine drip, had no effect. Only after her European emergency card for glucocorticoid cover was found, adrenal crisis was recognized, and she was immediately given an intravenous bolus of hydrocortisone followed by continuous hydrocortisone infusion. The patient rapidly improved and was transferred to a regular ward the next day, where hydrocortisone dose was gradually tapered. Our experience might suggest that patients with Addison's disease should probably start their treatment with zoledronic acid in a hospital setting. Their usual oral dose of hydrocortisone should be doubled or even tripled. Careful monitoring of these patients seems to be warranted, and intravenous hydrocortisone should be given if any symptoms or signs of the imminent adrenal crisis are noted.

The effects of systemic treatment with aminobisphosphonates and statins on circulating Vγ9Vδ2-T cells in patients with advanced cancer.

Aminobisphosphonates (NBP) are used for treatment of metastatic bone disease. Frequently, patients undergoing NBP-treatment experience side-effects, known as acute phase response (APR), resulting from cytokine production by Vγ9Vδ2-T cells. As opposed to NBP, statins reduce intracellular phosphoantigen levels and prevent NBP-induced Vγ9Vδ2-T cell activation in vitro. We conducted a pilot study in patients with (bone-)metastasized malignancies receiving NBP-treatment and evaluated the phenotype and function of circulating Vγ9Vδ2-T cells in vivo and the effects of statins on Vγ9Vδ2-T cell responses and the associated APR. We observed reduced expression of perforin, granzyme B and HLA-DR on Vγ9Vδ2-T cells in patients treated with NBP and statins. However, statins could not prevent NBP-induced changes in circulating Vγ9Vδ2-T cell numbers or production of IFNγ and TNFα. Consistent with this, simvastatin could not prevent the occurrence of APR upon NBP-infusion. These observations call for the exploration of alternative strategies to prevent collateral APR upon NBP treatment.

Hypoalbuminemia and Clinical Outcomes: What is the Mechanism behind the Relationship?

Albumin has a number of important physiologic functions, which include maintaining oncotic pressure, transporting various agents (fatty acids, bile acids, cholesterol, metal ions, and drugs), scavenging free oxygen radicals, acting as an antioxidant, and exerting an antiplatelet effect. Hypoalbuminemia in adults, defined by an intravascular albumin level of <3.5 g/dL, is associated with poor postoperative outcomes in patients undergoing surgical intervention. Although the relationship of hypoalbuminemia and poor surgical outcome has been known for many years, the pathophysiology behind the relationship is unclear. Three theoretical constructs might explain this relationship. First, albumin might serve as a nutritional marker, such that hypoalbuminemia represents poor nutritional status in patients who go on to experience poor postoperative outcomes. Second, albumin has its own pharmacologic characteristics as an antioxidant or transporter, and therefore, the lack of albumin might result in a deficiency of those functions, resulting in poor postoperative outcomes. Or third, albumin is known to be a negative acute phase protein, and as such hypoalbuminemia might represent an increased inflammatory status of the patient, potentially leading to poor outcomes. A thorough review of the literature reveals the fallacy of these arguments and fails to show a direct cause and effect between low albumin levels per se and adverse outcomes. Interventions designed solely to correct preoperative hypoalbuminemia, in particular intravenous albumin infusion, do little to change the patient's course of hospitalization. While surgeons may use albumin levels on admission for their prognostic value, they should avoid therapeutic strategies whose main endpoint is correction of this abnormality.

Carotenoids buffer the acute phase response on fever, sickness behavior and rapid bill color change in zebra finches.

Carotenoids are finite resources that animals can allocate to self-maintenance, attractiveness or reproduction. Here we test how carotenoids affect the acute phase response (APR), an intense rapid systemic response characterized by fever, sickness behavior and production of acute phase proteins, which serves to reduce pathogen persistence. We conducted a 2×2 factorial design experiment in captive adult male and female zebra finches (Taeniopygia guttata) to determine the effects of carotenoid supplementation on the intensity of the APR. We measured changes in feeding rate, activity level and body temperature of the birds. We found that, relative to unsupplemented controls, carotenoid-supplemented birds exhibited less severe reductions in feeding and activity, smaller increases in body temperature and lower circulating levels of haptoglobin (an acute phase protein) 24 h after inducing an APR. Among supplemented individuals, those with higher blood carotenoid levels exhibited a lower reduction in activity rate after 24 h. Forty-eight hours after APR induction, birds exhibited a significant decrease in plasma carotenoid levels and a decrease in bill hue, with less reduction in hue in carotenoid-supplemented individuals. These results demonstrate that carotenoids can alleviate several important behavioral and physiological effects of an APR and that bill color can change rapidly following induction of the costly APR immune defense. In particular, immune activation may have caused birds to preferentially draw down carotenoids from the bloodstream, ostensibly for use in health. Rapid bill color changes over a 48-h period support growing evidence that bills may serve as short-term signals of health and condition.

Double-Edged Sword: Musculoskeletal Infection Provoked Acute Phase Response in Children.

The acute phase response has a crucial role in mounting the body's response to tissue injury. Excessive activation of the acute phase response is responsible for many complications that occur in orthopedic patients. Given that infection may be considered continuous tissue injury that persistently activates the acute phase response, children with musculoskeletal infections are at markedly increased risk for serious complications. Future strategies that modulate the acute phase response have the potential to improve treatment and prevent complications associated with musculoskeletal infection.

Characterizing the Acute Phase Response in Healthy Patients Following Total Joint Arthroplasty: Predictable and Consistent.

BACKGROUND: During surgery, trauma to musculoskeletal tissue induces a systemic reaction known as the acute phase response (APR). When excessive or prolonged, the APR has been implicated as an underlying cause of surgical complications. The purpose of this study was to determine the typical APR following total joint arthroplasty in a healthy population defined by the Charlson Comorbidity Index (CCI). METHODS: This retrospective study identified 180 healthy patients (CCI < 2) who underwent total joint arthroplasty by a single surgeon for primary osteoarthritis from 2013 to 2015. Serial measurements of C-reactive protein (CRP) and fibrinogen were obtained preoperative, perioperative, and at 2 and 6 weeks postoperative. RESULTS: Postoperative CRP peaked during the inpatient period and returned to baseline by 2 weeks. Fibrinogen peaked after CRP and returned to baseline by 6 weeks. Elevated preoperative CRP correlated with a more robust postoperative APR for both total hip arthroplasty and total knee arthroplasty, suggesting that a patient's preoperative inflammatory state correlates with the magnitude of the postoperative APR. CONCLUSION: Measurement of preoperative acute phase reactants may provide an objective means to predict a patient's risk of postoperative dysregulation of the APR and complications.

Long-Term Impact of Postoperative Complications on Cancer Recurrence Following Lung Cancer Surgery.

BACKGROUND: Postoperative complications are associated with poor cancer-specific survival in various types of cancer surgery. Recent studies suggest that systemic inflammation induced by surgical trauma can accelerate the adhesion of circulating tumor cells to the vascular endothelium of distant organs, resulting in early cancer recurrence. We investigated the impact of postoperative cardiopulmonary complications on cancer recurrence following lung cancer surgery. METHODS: From a prospective database of 675 consecutive patients who underwent curative surgery for lung cancer between 2007 and 2012, the incidence of postoperative cardiopulmonary complications, white blood cell counts, and C-reactive protein levels were evaluated in the acute phase after surgery. Four patients had both cardiovascular and respiratory complications. The remaining 671 patients were divided into 3 groups: patients without cardiopulmonary complications; those with cardiovascular complications; and those with respiratory complications. The incidence of cancer recurrence was compared among the three groups. RESULTS: Postoperative cardiovascular or respiratory complications were identified in 94 (14%) or 25 (4%) patients, respectively. Postoperative white blood cell counts and C-reactive protein levels were significantly higher in those with postoperative respiratory complications than in those without. There was a significantly higher incidence of cancer recurrence in those with postoperative respiratory complications than in those without (48.0 vs. 16.8%; p < 0.0001). Multiple regression analysis adjusted for age, sex, and pathological staging showed that the incidence of postoperative respiratory complications was a significant predictor of cancer recurrence. CONCLUSIONS: The presence of respiratory complications following lung cancer surgery was a significant predictor of cancer recurrence.

Correlations between the levels of acute infection markers and serum albumin in elderly patients with hip fracture.

OBJECTIVE: The aim of this study was to explore a clinical index that could predict the decline of serum albumin (ALB) in elderly patients (over 60 years old) with hip fractures in 2014. METHODS: All the data came from the retrospective survey, and the correlations between the ALB changes and acute infection markers were then analyzed using correlation analysis. The changes of infection markers and ALB before and after surgery were compared using the t test. RESULTS: There was no correlation of the serum ALB blood with interleukin-6 (IL-6) (r = 0.072, P = 0.588), C-reactive protein (CRP) (r = -0.249, P = 0.057), or calcitonin (PCT) (r = -0.038, P = 0.775) when patients were admitted, but it was negatively correlated with the total amount of infection markers (TAIMs) (r = -0.301, P = 0.020). The postoperative levels of IL-6 (154.23 ± 177.14 pg/mL) (P < 0.001), CRP (69.52 ± 39.84 mg/L) (P < 0.001), and PCT (1.27 ± 2.4 ng/mL) (P < 0.001) were significantly increased than those before surgery [IL-6 (44.96 ± 54.58 pg/mL), CRP (31.78 ± 29.90 mg/L), and PCT (0.42 ± 1.06 ng/mL)]. The postoperative level of serum ALB (29.93 ± 3.02 g/L) was significantly reduced than that before surgery (33.95 ± 3.69 g/L) (P < 0.001). The serum ALB level was negatively correlated with IL-6 (r = -0.333, P = 0.015) before surgery, but not correlated with TAIMs (r = -0.256, P = 0.061). The serum ALB level was negatively correlated with IL-6 (r = -0.292, P = 0.034) and TAIMs (r = -0.271, P = 0.050) after surgery. CONCLUSIONS: The serum IL-6 level could predict the changes of ALB during the disease process.

Comparison of the acute-phase response after laparoscopic versus open aortobifemoral bypass surgery: a substudy of a randomized controlled trial.

PURPOSE: Minimally invasive surgical techniques have been shown to reduce the inflammatory response related to a surgical procedure. The main objective of our study was to measure the inflammatory response in patients undergoing a totally laparoscopic versus open aortobifemoral bypass surgery. This is the first randomized trial on subjects in this population. PATIENTS AND METHODS: This is a substudy of a larger randomized controlled multicenter trial (Norwegian Laparoscopic Aortic Surgery Trial). Thirty consecutive patients with severe aortoiliac occlusive disease eligible for aortobifemoral bypass surgery were randomized to either a totally laparoscopic (n=14) or an open surgical procedure (n=16). The inflammatory response was measured by perioperative monitoring of serum interleukin-6 (IL-6), IL-8, and C-reactive protein (CRP) at six different time points. RESULTS: The inflammatory reaction caused by the laparoscopic procedure was reduced compared with open surgery. IL-6 was significantly lower after the laparoscopic procedure, measured by comparing area under the curve (AUC), and after adjusting for the confounding effect of coronary heart disease (P=0.010). The differences in serum levels of IL-8 and CRP did not reach statistical significance. CONCLUSION: In this substudy of a randomized controlled trial comparing laparoscopic and open aortobifemoral bypass surgeries, we found a decreased perioperative inflammatory response after the laparoscopic procedure measured by comparing AUC for serum IL-6.

Early post-operative acute phase response in patients with early graft dysfunction is predictive of 6-month and 12-month mortality in liver transplant recipients.

UNLABELLED: Early allograft dysfunction (EAD) after liver transplantation is mostly a reversible event caused by factors related to ischemia/reperfusion (I/R) injury. EAD represents a hepatic injury associated with pre- and early post-transplant inflammatory cytokine responses. Aim of the present study was to evaluate the prognostic and diagnostic value of CRP in liver transplant recipients with EAD. MATERIALS AND METHODS: Forty-seven patients with EAD were compared with 115 non-EAD patients. Pre- and post-transplant parameters were analyzed. EAD was defined based on postoperative liver function tests such as INR, bilirubin and liver enzymes. Statistical analysis was performed using SPSS version 18.0. RESULTS: Pre-transplant liver enzyme were not significantly different in the two groups. At day 3, 5 and 10 post-transplant CRP was significantly higher in patients with EAD than in non-EAD patients (p⩽0.001 for all investigations) and remained consistently high in patients with EAD and low in non-EAD patients. EAD patients with high CRP at post-transplant days 3 and 5 showed lower survival at 6-month and 12-month post-transplant than patients with low CRP. CONCLUSION: Our results indicate a prognostic and diagnostic value of CRP in patients with early graft dysfunction and predict 6-month and 12-month mortality in liver transplant recipients.

Distending Pressure Did Not Activate Acute Phase or Inflammatory Responses in the Airways and Lungs of Fetal, Preterm Lambs.

BACKGROUND: Mechanical ventilation at birth causes airway injury and lung inflammation in preterm sheep. Continuous positive airway pressure (CPAP) is being increasingly used clinically to transition preterm infants at birth. OBJECTIVE: To test if distending pressures will activate acute phase reactants and inflammatory changes in the airways of fetal, preterm lambs. METHODS: The head and chest of fetal lambs at 128±1 day GA were surgically exteriorized. With placental circulation intact, fetal lambs were then randomized to one of five 15 minute interventions: PEEP of 0, 4, 8, 12, or 16 cmH2O. Recruitment volumes were recorded. Fetal lambs remained on placental support for 30 min after the intervention. The twins of each 0 cmH2O animal served as controls. Fetal lung fluid (FLF), bronchoalveolar lavage fluid (BAL), right mainstem bronchi and peripheral lung tissue were evaluated for inflammation. RESULTS: Recruitment volume increased from 0.4±0.04 mL/kg at 4 cmH2O to 2.4±0.3 mL/kg at 16 cmH2O. The lambs were surfactant deficient, and all pressures were below the opening inflection pressure on pressure-volume curve. mRNA expression of early response genes and pro-inflammatory cytokines did not increase in airway tissue or lung tissue at any pressure compared to controls. FLF and BAL also did not have increases in early response proteins. No histologic changes or Egr-1 activation was present at the pressures used. CONCLUSION: Distending pressures as high as 16 cmH2O did not recruit lung volume at birth and did not increase markers of injury in the lung or airways in non-breathing preterm fetal sheep.

Acute lung injury induced by whole gastric fluid: hepatic acute phase response contributes to increase lung antiprotease protection.

BACKGROUND: Gastric contents aspiration in humans is a risk factor for severe respiratory failure with elevated mortality. Although aspiration-induced local lung inflammation has been studied in animal models, little is known about extrapulmonary effects of aspiration. We investigated whether a single orotracheal instillation of whole gastric fluid elicits a liver acute phase response and if this response contributes to enrich the alveolar spaces with proteins having antiprotease activity. METHODS: In anesthetized Sprague-Dawley rats receiving whole gastric fluid, we studied at different times after instillation (4 h -7 days): changes in blood cytokines and acute phase proteins (fibrinogen and the antiproteases alpha1-antitrypsin and alpha2-macroglobulin) as well as liver mRNA expression of the two antiproteases. The impact of the systemic changes on lung antiprotease defense was evaluated by measuring levels and bioactivity of antiproteases in broncho-alveolar lavage fluid (BALF). Markers of alveolar-capillary barrier derangement were also studied. Non-parametric ANOVA (Kruskall-Wallis) and linear regression analysis were used. RESULTS: Severe peribronchiolar injury involving edema, intra-alveolar proteinaceous debris, hemorrhage and PMNn cell infiltration was seen in the first 24 h and later resolved. Despite a large increase in several lung cytokines, only IL-6 was found elevated in blood, preceding increased liver expression and blood concentration of both antiproteases. These changes, with an acute phase response profile, were significantly larger for alpha2-macroglobulin (40-fold increment in expression with 12-fold elevation in blood protein concentration) than for alpha1-antitrypsin (2-3 fold increment in expression with 0.5-fold elevation in blood protein concentration). Both the increment in capillary-alveolar antiprotease concentration gradient due to increased antiprotease liver synthesis and a timely-associated derangement of the alveolar-capillary barrier induced by aspiration, contributed a 58-fold and a 190-fold increase in BALF alpha1-antitrypsin and alpha2-macroglobulin levels respectively (p < 0.001). CONCLUSIONS: Gastric contents-induced acute lung injury elicits a liver acute phase response characterized by increased mRNA expression of antiproteases and elevation of blood antiprotease concentrations. Hepatic changes act in concert with derangement of the alveolar capillary barrier to enrich alveolar spaces with antiproteases. These findings may have significant implications decreasing protease burden, limiting injury in this and other models of acute lung injury and likely, in recurrent aspiration.

Study of the immunomodulatory properties of gamithromycin and dexamethasone in a lipopolysaccharide inflammation model in calves.

The aim of this study was to define the in vivo immunomodulatory properties of the macrolide antibiotic gamithromycin in calves, with respect to the acute phase response. Additionally, the corticosteroid dexamethasone was included as a positive control immunomodulatory drug. Both drugs, as well as their combination,were studied in a previously developed inflammation model,which was initiated by an intravenous lipopolysaccharide (LPS) challenge (0.5 µg/kg body weight). Twenty-four 4-week-old male Holstein Friesian calves were randomized into four groups: no pharmacological treatment (n = 6) or a pharmacological treatment with gamithromycin (n= 6), dexamethasone (n= 6) or their combination (n= 6) 1 h prior to LPS administration. Blood collection and clinical scoring were performed at regular time points until 72 h post LPS challenge. Plasma concentrations of selected cytokines (tumour necrosis factor-α (TNF-α) and interleukin 6 (IL-6)) and acute phase proteins (serum amyloid A and haptoglobin) were subsequently determined. Gamithromycin did not have any beneficial effect on the LPS-induced clinical signs (dyspnea, fever, anorexia and depression), nor on the studied inflammatory mediators. In the dexamethasone and combination groups, the occurrence of dyspnea and fever was not prominently influenced, although the calves recovered significantly faster from the challenge. Moreover, dexamethasone significantly inhibited the levels of TNF-α and IL-6, suggesting a key role for these cytokines in sickness behaviour. In conclusion, unlike dexamethasone, gamithromycin did not directly reduce cytokine release in an LPS inflammation model in calves.