Hydroxycarboxylic acid receptor 3 and GPR84 - Two metabolite-sensing G protein-coupled receptors with opposing functions in innate immune cells.

G protein-coupled receptors (GPCRs) are key regulatory proteins of immune cell function inducing signaling in response to extracellular (pathogenic) stimuli. Although unrelated, hydroxycarboxylic acid receptor 3 (HCA3) and GPR84 share signaling via Gαi/o proteins and the agonist 3-hydroxydecanoic acid (3HDec). Both receptors are abundantly expressed in monocytes, macrophages and neutrophils but have opposing functions in these innate immune cells. Detailed insights into the molecular mechanisms and signaling components involved in immune cell regulation by GPR84 and HCA3 are still lacking. Here, we report that GPR84-mediated pro-inflammatory signaling depends on coupling to the hematopoietic cell-specific Gα15 protein in human macrophages, while HCA3 exclusively couples to Gαi protein. We show that activated GPR84 induces Gα15-dependent ERK activation, increases intracellular Ca2+ and IP3 levels as well as ROS production. In contrast, HCA3 activation shifts macrophage metabolism to a less glycolytic phenotype, which is associated with anti-inflammatory responses. This is supported by an increased release of anti-inflammatory IL-10 and a decreased secretion of pro-inflammatory IL-1ß. In primary human neutrophils, stimulation with HCA3 agonists counteracts the GPR84-induced neutrophil activation. Our analyses reveal that 3HDec acts solely through GPR84 but not HCA3 activation in macrophages. In summary, this study shows that HCA3 mediates hyporesponsiveness in response to metabolites derived from dietary lactic acid bacteria and uncovers that GPR84, which is already targeted in clinical trials, promotes pro-inflammatory signaling via Gα15 protein in macrophages.

The M1311V variant of ATP7A is associated with impaired trafficking and copper homeostasis in models of motor neuron disease.

Disruption in copper homeostasis causes a number of cognitive and motor deficits. Wilson's disease and Menkes disease are neurodevelopmental disorders resulting from mutations in the copper transporters ATP7A and ATP7B, with ATP7A mutations also causing occipital horn syndrome, and distal motor neuropathy. A 65 year old male presenting with brachial amyotrophic diplegia and diagnosed with amyotrophic lateral sclerosis (ALS) was found to harbor a p.Met1311Val (M1311V) substitution variant in ATP7A. ALS is a fatal neurodegenerative disease associated with progressive muscle weakness, synaptic deficits and degeneration of upper and lower motor neurons. To investigate the potential contribution of the ATP7AM1311V variant to neurodegeneration, we obtained and characterized both patient-derived fibroblasts and patient-derived induced pluripotent stem cells differentiated into motor neurons (iPSC-MNs), and compared them to control cell lines. We found reduced localization of ATP7AM1311V to the trans-Golgi network (TGN) at basal copper levels in patient-derived fibroblasts and iPSC-MNs. In addition, redistribution of ATP7AM1311V out of the TGN in response to increased extracellular copper was defective in patient fibroblasts. This manifested in enhanced intracellular copper accumulation and reduced survival of ATP7AM1311V fibroblasts. iPSC-MNs harboring the ATP7AM1311V variant showed decreased dendritic complexity, aberrant spontaneous firing, and decreased survival. Finally, expression of the ATP7AM1311V variant in Drosophila motor neurons resulted in motor deficits. Apilimod, a drug that targets vesicular transport and recently shown to enhance survival of C9orf72-ALS/FTD iPSC-MNs, also increased survival of ATP7AM1311V iPSC-MNs and reduced motor deficits in Drosophila expressing ATP7AM1311V. Taken together, these observations suggest that ATP7AM1311V negatively impacts its role as a copper transporter and impairs several aspects of motor neuron function and morphology.

Activity of trastuzumab emtansine (T-DM1) in 3D cell culture.

BACKGROUND: Cell spheroids and aggregates generated from three-dimensional (3D) cell culture methods are similar to in vivo tumors in terms of tissue morphology, biology, and gene expression, unlike cells grown in 2D cell cultures. Breast cancer heterogeneity is one of the main drug resistant mechanisms and needs to be overcome in order to increase the efficacy of drug activity in its treatments. METHODS: We performed a unique 3D cell culture and drug efficacy study with trastuzumab emtansine (Kadcyla®, T-DM1) across five breast cancer cell lines (BT-474, SK-BR-3, MDA-MB-361, MDA-MB-175, and MCF-7) that were previously investigated in 2D cell culture. We performed HER2 IHC staining, cell viability experiments, Gene-protein-assay (GPA), and T-DM1 internalization studies. RESULTS: We obtained significantly different results including higher IC50 for some of the cell lines. Our GPA showed some significant heterogeneous HER2 gene and protein expression in 3D cultured spheroids or aggregates. The fluorescent images also showed that a longer incubation time is needed for T-DM1 to be internalized effectively into 3D cultured spheroids or aggregates. CONCLUSION: Our study demonstrated that the difference of T-DM1 drug activity in 3D spheroids or aggregates might be due to tumor heterogeneity and less efficient internalization of T-DM1 that is not seen using 2D cell culture models. Drug studies using 3D cell culture are expected to provide biologically relevant models for determining drug activity in tumor tissue in future drug response and resistance research.

Outcomes in primary cutaneous diffuse large B-cell lymphoma, leg type.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT) is a rare, aggressive lymphoma characterized by skin involvement predominantly in the lower extremities. Immunochemotherapy with or without involved-site radiation therapy (ISRT) is considered standard front-line therapy. Over-expression of PD-L1/PD-L2 is seen in a high proportion of PCDLBCL, LT cases, but efficacy of immune checkpoint inhibitors (ICI) in relapsed/refractory, PCDLBCL, LT has not been thoroughly studied. We conducted a retrospective cohort study of patients diagnosed with PCDLBCL, LT seen at Mayo Clinic from 1 January 2000 to 31 December 2020. Using the Kaplan-Meier method, we calculated progression-free survival, duration of response, and overall survival in patients who received front-line rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) with and without ISRT, and salvage ICI therapy for relapsed/refractory disease. A total of 28 patients with PCDLBCL, LT were identified. The median PFS in patients treated with R-CHOP plus ISRT was 58 months (95% CI: 18-112) compared to 14 months (95% CI: 5-not reached; p = 0.04) in those treated with R-CHOP without ISRT. The median PFS from salvage ICI therapy was 10 months (95% CI: 4-not reached), and median DOR from salvage ICI therapy was 23 months [95% CI: 4-26]. R-CHOP with ISRT had a significantly longer median PFS compared to R-CHOP without ISRT as front-line therapy for PCDLBCL, LT. ICIs may have a role in treating relapsed/refractory disease as reasonable activity in heavily pre-treated patients was observed in this study.

Exploring G Protein-Coupled Receptor Signaling in Primary Pancreatic Islets.

BACKGROUND: Targeting G protein-coupled receptors (GPCRs) in pancreatic cells is feasible to modulate glucose-induced insulin secretion. Because pancreatic islets consist of several cell types and GPCRs can couple to more than one G-protein family, results obtained in pancreatic cell lines do not always match the response in primary cells or intact islets. Therefore, we set out to establish a protocol to analyze second messenger activation in mouse pancreatic islets. RESULTS: Activation of Gq/11-coupled receptor expressed in primary ß cells increased the second messenger IP1 in an accumulation assay. Applying a Gq/11 protein inhibitor completely abolished this signal. Activation of the V1 vasopressin and ghrelin receptors, predominantly expressed in the less abundant alpha and delta cells, was not sufficient to induce a significant IP1 increase in this assay. However, fura-2-based fluorescence imaging showed calcium signals upon application of arginine vasopressin or ghrelin within intact pancreatic islets. Using the here established protocol we were also able to determine changes in intracellular cAMP levels induced by receptors coupling to Gs and Gi/o proteins. CONCLUSIONS: Detection of the second messengers IP1, cAMP, and calcium, can be used to reliably analyze GPCR activation in intact islets.

Natural biased signaling of hydroxycarboxylic acid receptor 3 and G protein-coupled receptor 84.

BACKGROUND: Medium-chain fatty acids and their 3-hydroxy derivatives are metabolites endogenously produced in humans, food-derived or originating from bacteria. They activate G protein-coupled receptors, including GPR84 and HCA3, which regulate metabolism and immune functions. Although both receptors are coupled to Gi proteins, share at least one agonist and show overlapping tissue expression, GPR84 exerts pro-inflammatory effects whereas HCA3 is involved in anti-inflammatory responses. Here, we analyzed signaling kinetics of both HCA3 and GPR84, to unravel signal transduction components that may explain their physiological differences. METHODS: To study the signaling kinetics and components involved in signal transduction of both receptors we applied the label-free dynamic mass redistribution technology in combination with classical cAMP, ERK signaling and ß-arrestin-2 recruitment assays. For phenotypical analyses, we used spheroid cell culture models. RESULTS: We present strong evidence for a natural biased signaling of structurally highly similar agonists at HCA3 and GPR84. We show that HCA3 signaling and trafficking depends on dynamin-2 function. Activation of HCA3 by 3-hydroxyoctanoic acid but not 3-hydroxydecanoic acid leads to ß-arrestin-2 recruitment, which is relevant for cell-cell adhesion. GPR84 stimulation with 3-hydroxydecanoic acid causes a sustained ERK activation but activation of GPR84 is not followed by ß-arrestin-2 recruitment. CONCLUSIONS: In summary, our results highlight that biased agonism is a physiological property of HCA3 and GPR84 with relevance for innate immune functions potentially to differentiate between endogenous, non-pathogenic compounds and compounds originating from e.g. pathogenic bacteria. Video Abstract.

Loss of Orai2-Mediated Capacitative Ca2+ Entry Is Neuroprotective in Acute Ischemic Stroke.

Background and Purpose- Ischemic stroke is one of the leading causes of disability and death. The principal goal of acute stroke treatment is the recanalization of the occluded cerebral arteries, which is, however, only effective in a very narrow time window. Therefore, neuroprotective treatments that can be combined with recanalization strategies are needed. Calcium overload is one of the major triggers of neuronal cell death. We have previously shown that capacitative Ca2+ entry, which is triggered by the depletion of intracellular calcium stores, contributes to ischemia-induced calcium influx in neurons, but the responsible Ca2+ channel is not known. Methods- Here, we have generated mice lacking the calcium channel subunit Orai2 and analyzed them in experimental stroke. Results- Orai2-deficient mice were protected from ischemic neuronal death both during acute ischemia under vessel occlusion and during ischemia/reperfusion upon successful recanalization. Calcium signals induced by calcium store depletion or oxygen/glucose deprivation were significantly diminished in Orai2-deficient neurons demonstrating that Orai2 is a central mediator of neuronal capacitative Ca2+ entry and is involved in calcium overload during ischemia. Conclusions- Our experimental data identify Orai2 as an attractive target for pharmaceutical intervention in acute stroke.

Leiomodin 3 and tropomodulin 4 have overlapping functions during skeletal myofibrillogenesis.

Precise regulation of thin filament length is essential for optimal force generation during muscle contraction. The thin filament capping protein tropomodulin (Tmod) contributes to thin filament length uniformity by regulating elongation and depolymerization at thin filament ends. The leiomodins (Lmod1-3) are structurally related to Tmod1-4 and also localize to actin filament pointed ends, but in vitro biochemical studies indicate that Lmods act instead as robust nucleators. Here, we examined the roles of Tmod4 and Lmod3 during Xenopus skeletal myofibrillogenesis. Loss of Tmod4 or Lmod3 resulted in severe disruption of sarcomere assembly and impaired embryonic movement. Remarkably, when Tmod4-deficient embryos were supplemented with additional Lmod3, and Lmod3-deficient embryos were supplemented with additional Tmod4, sarcomere assembly was rescued and embryonic locomotion improved. These results demonstrate for the first time that appropriate levels of both Tmod4 and Lmod3 are required for embryonic myofibrillogenesis and, unexpectedly, both proteins can function redundantly during in vivo skeletal muscle thin filament assembly. Furthermore, these studies demonstrate the value of Xenopus for the analysis of contractile protein function during de novo myofibril assembly.

The relationship between nernst equilibrium variability and the multifractality of interspike intervals in the hippocampus.

Spatiotemporal patterns of action potentials are considered to be closely related to information processing in the brain. Auto-generating neurons contributing to these processing tasks are known to cause multifractal behavior in the inter-spike intervals of the output action potentials. In this paper we define a novel relationship between this multifractality and the adaptive Nernst equilibrium in hippocampal neurons. Using this relationship we are able to differentiate between various drugs at varying dosages. Conventional methods limit their ability to account for cellular charge depletion by not including these adaptive Nernst equilibria. Our results provide a new theoretical approach for measuring the effects which drugs have on single-cell dynamics.

Assessments of Fatty Infiltration and Muscle Atrophy From a Single Magnetic Resonance Image Slice Are Not Predictive of 3-Dimensional Measurements.

PURPOSE: To (1) determine whether standard clinical muscle fatty infiltration and atrophy assessment techniques using a single image slice for patients with a rotator cuff tear (RCT) are correlated with 3-dimensional measures in older individuals (60+ years) and (2) to determine whether age-associated changes to muscle morphology and strength are compounded by an RCT. METHODS: Twenty older individuals were studied: 10 with an RCT of the supraspinatus (5 men and 5 women) and 10 matched controls. Clinical imaging assessments (Goutallier and Fuchs scores and cross-sectional area ratio) were performed for participants with RCTs. Three-dimensional measurements of rotator cuff muscle and fat tissues were obtained for all participants using magnetic resonance imaging (MRI). Isometric joint moment was measured at the shoulder. RESULTS: There were no significant associations between single-image assessments and 3-dimensional measurements of fatty infiltration for the supraspinatus and infraspinatus muscles. Compared with controls, participants with RCTs had significantly increased percentages of fatty infiltration for each rotator cuff muscle (all P ≤ .023); reduced whole muscle volume for the supraspinatus, infraspinatus, and subscapularis muscles (all P ≤ .038); and reduced fat-free muscle volume for the supraspinatus, infraspinatus, and subscapularis muscles (all P ≤ .027). Only the teres minor (P = .017) fatty infiltration volume was significantly greater for participants with RCTs. Adduction, flexion, and external rotation strength (all P ≤ .021) were significantly reduced for participants with RCTs, and muscle volume was a significant predictor of strength for all comparisons. CONCLUSIONS: Clinical scores using a single image slice do not represent 3-dimensional muscle measurements. Efficient methods are needed to more effectively capture 3-dimensional information for clinical applications. Participants with RCTs had increased fatty infiltration percentages that were likely driven by muscle atrophy rather than increased fat volume. The significant association of muscle volume with strength production suggests that treatments to preserve muscle volume should be pursued for older patients with RCTs. LEVEL OF EVIDENCE: Level II, diagnostic study, with development of diagnostic criteria on the basis of consecutive patients with universally applied reference gold standard.

STIM1, STIM2, and Orai1 regulate store-operated calcium entry and purinergic activation of microglia.

Activation of microglia is the first and main immune response to brain injury. Release of the nucleotides ATP, ADP, and UDP from damaged cells regulate microglial migration and phagocytosis via purinergic P2Y receptors. We hypothesized that store-operated Ca(2+) entry (SOCE), the prevalent Ca(2+) influx mechanism in non-excitable cells, is a potent mediator of microglial responses to extracellular nucleotides. Expression analyses of STIM Ca(2+) sensors and Orai Ca(2+) channel subunits, that comprise the molecular machinery of SOCE, showed relevant levels of STIM1, STIM2, and Orai1 in cultured mouse microglia. STIM1 expression and SOCE were down-regulated by treatment of microglia with lipopolysaccharide, suggesting that inflammation limits SOCE by lower STIM1 abundance. Ca(2+) entry induced by cyclopiazonic acid, ATP, the P2Y6 receptor agonist UDP, or the P2Y12 receptor agonist 2-methylthio-ADP (2-MeSADP) was clearly affected in microglia from Stim1(-/-) , Stim2(-/-) , and Orai1(-/-) mice. SOCE blockers or ablation of STIM1, STIM2, or Orai1 severely impaired nucleotide-induced migration and phagocytosis in microglia. Thus, this study assigns SOCE, regulated by STIM1, STIM2, and Orai1 an essential role in purinergic signaling and activation of microglia.

The role of biological sex in severely traumatized patients on outcomes: a matched-pair analysis.

OBJECTIVE: Analyze sex differences in TraumaRegister DGU (TR-DGU). BACKGROUND: Sex differences are considered to influence trauma outcomes. However, clinical study results are controversial. METHODS: Of 29,353 prospectively recorded cases of TR-DGU, we included primary trauma room admissions with Injury Severity Score of 9 or more into the analysis. Pairs (n = 3887) were formed from 1 male and 1 female according to age, mechanism, injury severity by Abbreviated Injury Scale (for head, thorax, abdomen, extremities), and occurrence of prehospital shock. Biochemical markers, treatment modalities, length of stay, and outcome (multiple organ failure, sepsis, mortality rates) were assessed. Statistical significance was accepted at P < 0.05. Odds ratios (ORs) are given with 95% confidence interval (CI). RESULTS: Females had less multiple organ failure [OR: 1.18 (95% CI, 1.05-1.33); P = 0.007], particularly in age group of 16 to 44 years; sepsis [OR: 1.45 (95% CI, 1.21-1.74); P < 0.001]), particularly at age more than 45 years; and mortality [OR: 1.14 (95% CI, 1.01-1.28); P = 0.037]. Prehospital chest tube insertions (214 vs 158) and surgical procedures before intensive care unit admission were more often performed in males (79.7% vs 76.4%). Females had lower mean hemoglobin levels [10.7 ± 2.6 vs 11.9 ± 2.8 (mg/dL)]. There were no sex differences in fluid resuscitation, shock index, coagulation, and base excess. CONCLUSIONS: Males are more susceptible to multiple organ failure, sepsis, and mortality after trauma. Differences were not exclusively related to reproductive age and thus cannot be attributed to sex hormones alone. Females aged 16 to 44 years seem to tolerate shock better. Higher susceptibility to sepsis might be explained by male immune function or increased systemic burden from higher rates of surgical interventions.

Morbidity and survival probability in burn patients in modern burn care.

OBJECTIVE: Characterizing burn sizes that are associated with an increased risk of mortality and morbidity is critical because it would allow identifying patients who might derive the greatest benefit from individualized, experimental, or innovative therapies. Although scores have been established to predict mortality, few data addressing other outcomes exist. The objective of this study was to determine burn sizes that are associated with increased mortality and morbidity after burn. DESIGN AND PATIENTS: Burn patients were prospectively enrolled as part of the multicenter prospective cohort study, Inflammation and the Host Response to Injury Glue Grant, with the following inclusion criteria: 0-99 years old, admission within 96 hours after injury, and more than 20% total body surface area burns requiring at least one surgical intervention. SETTING: Six major burn centers in North America. MEASUREMENTS AND MAIN RESULTS: Burn size cutoff values were determined for mortality, burn wound infection (at least two infections), sepsis (as defined by American Burn Association sepsis criteria), pneumonia, acute respiratory distress syndrome, and multiple organ failure (Denver 2 score>3) for both children (<16 yr) and adults (16-65 yr). Five hundred seventy-three patients were enrolled, of which 226 patients were children. Twenty-three patients were older than 65 years and were excluded from the cutoff analysis. In children, the cutoff burn size for mortality, sepsis, infection, and multiple organ failure was approximately 60% total body surface area burned. In adults, the cutoff for these outcomes was lower, at approximately 40% total body surface area burned. CONCLUSIONS: In the modern burn care setting, adults with over 40% total body surface area burned and children with over 60% total body surface area burned are at high risk for morbidity and mortality, even in highly specialized centers.

The effects of chronic alcohol self-administration in nonhuman primate brain networks.

BACKGROUND: Long-term alcohol abuse is associated with change in behavior, brain structure, and brain function. However, the nature of these changes is not well understood. In this study, we used network science to analyze a nonhuman primate model of ethanol self-administration to evaluate functional differences between animals with chronic alcohol use and animals with no exposure to alcohol. Of particular interest was how chronic alcohol exposure may affect the resting state network. METHODS: Baseline resting state functional magnetic resonance imaging was acquired in a cohort of vervet monkeys. Animals underwent an induction period where they were exposed to an isocaloric maltose dextrin solution (control) or ethanol in escalating doses over three 30-day epochs. Following induction, animals were given ad libitum access to water and a maltose dextrin solution (control) or water and ethanol for 22 h/d over 12 months. Cross-sectional analyses examined region of interests in hubs and community structure across animals to determine differences between drinking and nondrinking animals after the 12-month free access period. RESULTS: Animals were classified as lighter (<2.0 g/kg/d) or heavier drinkers (≥2.0 g/kg/d) based on a median split of their intake pattern during the 12-month ethanol free access period. Statistical analysis of hub connectivity showed significant differences in heavier drinkers for hubs in the precuneus, posterior parietal cortices, superior temporal gyrus, subgenual cingulate, and sensorimotor cortex. Heavier drinkers were also shown to have less consistent communities across the brain compared to lighter drinkers. The different level of consumption between the lighter and heavier drinking monkeys suggests that differences in connectivity may be intake dependent. CONCLUSIONS: Animals that consume alcohol show topological differences in brain network organization, particularly in animals that drink heavily. Differences in the resting state network were linked to areas that are associated with spatial association, working memory, and visuomotor processing.

Reliable scar scoring system to assess photographs of burn patients.

BACKGROUND: Several scar-scoring scales exist to clinically monitor burn scar development and maturation. Although scoring scars through direct clinical examination is ideal, scars must sometimes be scored from photographs. No scar scale currently exists for the latter purpose. MATERIALS AND METHODS: We modified a previously described scar scale (Yeong et al., J Burn Care Rehabil 1997) and tested the reliability of this new scale in assessing burn scars from photographs. The new scale consisted of three parameters as follows: scar height, surface appearance, and color mismatch. Each parameter was assigned a score of 1 (best) to 4 (worst), generating a total score of 3-12. Five physicians with burns training scored 120 representative photographs using the original and modified scales. Reliability was analyzed using coefficient of agreement, Cronbach alpha, intraclass correlation coefficient, variance, and coefficient of variance. Analysis of variance was performed using the Kruskal-Wallis test. Color mismatch and scar height scores were validated by analyzing actual height and color differences. RESULTS: The intraclass correlation coefficient, the coefficient of agreement, and Cronbach alpha were higher for the modified scale than those of the original scale. The original scale produced more variance than that in the modified scale. Subanalysis demonstrated that, for all categories, the modified scale had greater correlation and reliability than the original scale. The correlation between color mismatch scores and actual color differences was 0.84 and between scar height scores and actual height was 0.81. CONCLUSIONS: The modified scar scale is a simple, reliable, and useful scale for evaluating photographs of burn patients.

Voxel-based morphometry and arterial spin labeling fMRI reveal neuropathic and neuroplastic features of brain processing of itch in end-stage renal disease.

Pruritus of end-stage renal disease (ESRD) is a multifactorial symptom of complex etiology not yet fully understood. In this study we have investigated the cerebral perfusion patterns at rest in ESRD patients on hemodialysis, compared with those in healthy volunteers. We have also studied the brain responses evoked by experimental itch induction in ESRD, after stimulating the two distinct histamine and cowhage itch pathways, and compared them with the responses evoked in healthy volunteers. To identify potential structural alterations in ESRD patients compared with a group of age-matched healthy volunteers, we calculated the density of gray matter for the entire brain using a voxel-based morphometric analysis. Our results indicated that gray matter density was significantly reduced in ESRD patients in the frontal, parietal, temporal, and occipital cortices, as well as in the S1, precuneus, and insula, whereas the brain stem, hippocampus, amygdala, midcingulate cortex, and nucleus accumbens displayed an increased gray matter density. Functionally, we found a significantly higher brain perfusion at baseline associated with ESRD pruritus in the anterior cingulate, insula, claustrum, hippocampus, and nucleus accumbens. The brain responses evoked by cowhage itch, which are mediated by protease-activated receptors (PAR2), displayed significant differences compared with responses in healthy individuals and were correlated with perceived itch intensity in a dual, complex manner. The inverse correlations in particular suggested that a negative feedback mechanism modulated itch intensity, when elicited in a preexistent chronic itch background.

Occurrence of multiorgan dysfunction in pediatric burn patients: incidence and clinical outcome.

OBJECTIVE: To examine the incidence of single or multiple organ failure postburn and its resultant clinical outcomes during acute hospitalization. BACKGROUND: Patient outcomes are inherently dependent on intact organ function; however, burn injury affects the structure and function of almost every organ, but especially lung, liver, kidney, and heart. Therefore, single-organ failure and/or multiorgan failure (MOF) are thought to contribute significantly to postburn morbidity and mortality, but to date no large trial examining the effects of MOF on postburn outcomes exists. METHODS: Incidence of MOF was monitored in 821 pediatric burn patients during acute hospitalization. Patients were divided into groups on the basis of the incidence of single-organ-specific failure, MOF, and non-MOF. The DENVER2 score was used to assess organ-specific scores for lung, liver, kidney, and heart. The patient's demographics, injury characteristics, and outcome parameters were recorded. RESULTS: Respiratory failure has the highest incidence in the early phase of postburn injury and decreases starting 5 days postburn. Cardiac failure was noted to have the highest incidence throughout hospital stay. Incidence of hepatic failure increases with the hospital length of stay and is associated with a high mortality during the late phase of the acute hospital stay. Renal failure has an unexpectedly low incidence but is associated with a high mortality during the first 3 weeks postburn injury. Three or more organ failure is associated with very high mortality. CONCLUSIONS: This is the first large study in burn patients to determine the incidence of organ-specific failure and outcome. The results of this study confirmed the expected chronologic incidence of organ-specific failure and yield the long-term mortality from liver and renal failure.

Survivors versus nonsurvivors postburn: differences in inflammatory and hypermetabolic trajectories.

OBJECTIVE: To evaluate whether a panel of common biomedical markers can be utilized as trajectories to determine survival in pediatric burn patients. BACKGROUND: Despite major advances in clinical care, of the more than 1 million people burned in the United States each year, more than 4500 die as a result of their burn injuries. The ability to predict patient outcome or anticipate clinical trajectories using plasma protein expression would allow personalization of clinical care to optimize the potential for patient survival. METHODS: A total of 230 severely burned children with burns exceeding 30% of the total body surface, requiring at least 1 surgical procedure were enrolled in this prospective cohort study. Demographics, clinical outcomes, and inflammatory and acute-phase responses (serum cytokines, hormones, and proteins) were determined at admission and at 11 time points for up to 180 days postburn. Statistical analysis was performed using a 1-way analysis of variance, the Student t test, χ test, and Mann-Whitney test where appropriate. RESULTS: Survivors and nonsurvivors exhibited profound differences in critical markers of inflammation and metabolism at each time point. Nonsurvivors had significantly higher serum levels of interleukin (IL)-6, IL-8, granulocyte colony-stimulating factor, monocyte chemoattractant protein-1, C-reactive protein, glucose, insulin, blood urea nitrogen, creatinine, and bilirubin (P < 0.05). Furthermore, nonsurvivors exhibited a vastly increased hypermetabolic response that was associated with increases in organ dysfunction and sepsis when compared with survivors (P < 0.05). CONCLUSIONS: Nonsurvivors have different trajectories in inflammatory, metabolic, and acute phase responses allowing differentiation of nonsurvivors from survivors and now possibly allowing novel predictive models to improve and personalize burn outcomes.

Hypoglycemia is associated with increased postburn morbidity and mortality in pediatric patients.

OBJECTIVE: The objective of this study was to determine the prevalence of hypoglycemia after burn injury and whether hypoglycemia is associated with increased postburn morbidity and mortality. DESIGN: Cohort analysis. SETTING: Academic pediatric burn hospital. PATIENTS: This analysis included 760 pediatric burn patients, who were stratified according the number of hypoglycemic episodes (< 60 mg/dL glucose) they experienced while in the ICU. Clinical outcomes and metabolic and inflammatory biomarkers were analyzed during the first 60 days post admission. Patients with one or more hypoglycemic events were matched with patients not experiencing any event using propensity score matching, and outcomes and biomarker expression were compared between groups. MEASUREMENTS AND MAIN RESULTS: Eighty-four patients had one episode of hypoglycemia, 108 patients had two or more episodes of hypoglycemia, and 568 patients never experienced hypoglycemia. Patients with one or more hypoglycemic episodes had longer hospitalization, as well as more frequent infections, sepsis, multiple organ failure, and death (p < 0.05). The 166 propensity score-matched patients with one or more hypoglycemic events had greater inflammatory and metabolic responses, prevalence of sepsis, multiple organ failure, and mortality than burn patients without hypoglycemic (p < 0.05). CONCLUSIONS: Hypoglycemic episodes correlate with injury severity and inhalation injury. When adjusted for injury severity, hypoglycemia is associated with significantly higher postburn morbidity and mortality.

Target flow deviations on the cardiopulmonary bypass cause postoperative delirium in cardiothoracic surgery-a retrospective study evaluating temporal fluctuations of perfusion data.

OBJECTIVES: Postoperative delirium (POD) is common, costly and associated with long-term morbidity and increased mortality. We conducted a cohort study to assess the contribution of cardiopulmonary bypass (CPB) to the development of POD by means of algorithm-based data processing. METHODS: A database was compiled from 3 datasets of patients who underwent cardiac surgery between 2014 and 2019: intensive care unit discharge files, CPB protocols and medical quality management records. Following data extraction and structuring using novel algorithms, missing data were imputed. Ten independent imputations were analysed by multiple logistic regression with stepwise deletion of factors to arrive at a minimal adequate model. RESULTS: POD was diagnosed in 456/3163 patients (14.4%). In addition to known demographic risk factors and comorbidities like male sex, age, carotid disease, acute kidney failure and diabetes mellitus, cardiopulmonary parameters like total blood volume at the CPB [adjusted odds ratio (AOR) 1.001; confidence interval (CI) 1.1001-1.002] were independent predictors of POD. Higher values of the minimal blood flow were associated with a lower risk of POD (AOR 0.993; CI 0.988-0.997). Flow rates at least 30% above target did emerge in the minimal adequate model as a potential risk factor, but the confidence interval suggested a lack of statistical significance (AOR 1.819; 95% CI: 0.955-3.463). CONCLUSIONS: CPB data processing proved to be a useful tool for obtaining compact information to better identify the roles of individual operational states. Strict adherence to perfusion limits along with tighter control of blood flow and acid-base balance during CPB may help to further decrease the risk of POD.