Generation of C5a in the absence of C3: a new complement activation pathway.

Complement-mediated tissue injury in humans occurs upon deposition of immune complexes, such as in autoimmune diseases and acute respiratory distress syndrome. Acute lung inflammatory injury in wild-type and C3-/- mice after deposition of IgG immune complexes was of equivalent intensity and was C5a dependent, but injury was greatly attenuated in Hc-/- mice (Hc encodes C5). Injury in lungs of C3-/- mice and C5a levels in bronchoalveolar lavage (BAL) fluids from these mice were greatly reduced in the presence of antithrombin III (ATIII) or hirudin but were not reduced in similarly treated C3+/+ mice. Plasma from C3-/- mice contained threefold higher levels of thrombin activity compared to plasma from C3+/+ mice. There were higher levels of F2 mRNA (encoding prothrombin) as well as prothrombin and thrombin protein in liver of C3-/- mice compared to C3+/+ mice. A potent solid-phase C5 convertase was generated using plasma from either C3+/+ or C3-/- mice. Human C5 incubated with thrombin generated C5a that was biologically active. These data suggest that, in the genetic absence of C3, thrombin substitutes for the C3-dependent C5 convertase. This linkage between the complement and coagulation pathways may represent a new pathway of complement activation.

An essential role for complement C5a in the pathogenesis of septic cardiac dysfunction.

Defective cardiac function during sepsis has been referred to as "cardiomyopathy of sepsis." It is known that sepsis leads to intensive activation of the complement system. In the current study, cardiac function and cardiomyocyte contractility have been evaluated in rats after cecal ligation and puncture (CLP). Significant reductions in left ventricular pressures occurred in vivo and in cardiomyocyte contractility in vitro. These defects were prevented in CLP rats given blocking antibody to C5a. Both mRNA and protein for the C5a receptor (C5aR) were constitutively expressed on cardiomyocytes; both increased as a function of time after CLP. In vitro addition of recombinant rat C5a induced dramatic contractile dysfunction in both sham and CLP cardiomyocytes, but to a consistently greater degree in cells from CLP animals. These data suggest that CLP induces C5aR on cardiomyocytes and that in vivo generation of C5a causes C5a-C5aR interaction, causing dysfunction of cardiomyocytes, resulting in compromise of cardiac performance.

The accuracy of ACTH as a biomarker for pituitary pars intermedia dysfunction in horses: A systematic review and meta-analysis.

BACKGROUND: Accuracy of baseline ACTH for the diagnosis of PPID in horses varies between studies. OBJECTIVES: To estimate the diagnostic accuracy of ACTH as a biomarker for PPID in adult horses and appraise potential causes of heterogeneity. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A literature review identified studies reporting diagnostic accuracy data for extraction. Risk of bias was evaluated using QUADAS-2. Two random-effects models, the hierarchical summary receiver operating curve (HSROC) and the bivariate binomial normal model (BBN) were used to pool accuracy measurements. We performed meta-regression using study-level variables. The impact of diagnostic test accuracy on the frequency of false-positive and false-negative results at various pretest probabilities was calculated using the BBN model's accuracy results. RESULTS: Patient selection and index test evaluation demonstrated significant risk of bias. Mean and 95% confidence intervals for sensitivity and specificity for all studies (n = 11) based upon the HSROC model were (0.72, 95% CI: 0.62 to 0.82) and (0.88, 95% CI: 0.79 to 0.93), respectively. When studies with a common positivity threshold of 35 pg/mL ACTH were evaluated (n = 6), sensitivity and specificity were (0.66, 95% CI:0.54 to 0.77) and (0.87, 95% CI: 0.74 to 0.94). In a hypothetical group of one thousand horses with PPID prevalence of 2%, 20%, and 90%, the frequency of resulting false-positive and false-negatives would be (127 and 7), (104 and 68) and (13 and 306), respectively. Factors leading to increased accuracy were case-control design, clinical reference standard and data-driven choice of ACTH threshold. MAIN LIMITATIONS: A small number of primary studies (n = 11) were available, demonstrating significant biases. CONCLUSIONS: Less biased studies examining diagnostic accuracy of ACTH are needed. In horses with a high pretest probability of PPID, ACTH may be a functional "rule-in" test. Baseline ACTH is not recommended for screening purposes or use in horses without clinical signs of PPID.

Nonlinear fiber-bundle-cells-based phenomenological modeling of human tissue samples.

Certain assemblies of fibers, called fiber bundles, play a crucial role in the statistical macroscale properties of fibrous structures like natural or artificial materials. Based on the concept of using idealized statistical fiber bundle cells (FBCs) as model elements, the software named FiberSpace was developed by us earlier for the phenomenological modeling of the tensile test process of real fibrous structures. The model fibers of these FBCs had been considered linear elastic, which was suitable for modeling certain textiles and composites. However, the biological tissues are multilevel structures with fiber-like building elements on every structural level where the fiber elements on the dominant level are statistical bundles of elementary fibers. Hence, their modeling required us to introduce model fibers of nonlinear mechanical behavior and derive the proper mathematical formulas for the calculation of the expected tensile force processes of the FBCs. Accordingly, we developed a new version of FiberSpace. The proposed nonlinear FBCs-based modeling method is essentially phenomenological that decomposes the measured and averaged stress-strain curve into the weighted sum of the responses of different idealized nonlinear FBCs. However, this decomposition can give certain information about the fibrous structure and some details of its damage and failure sub-processes. A special application of nonlinear E-bundles, where the measured stress-strain curve is expanded into a product-function series, may give another type of description for the failure process and can be applied to single measurements of structured failure process containing significant peaks and drops as well. The fitted phenomenological FBC models provide a decomposition of the measured force-strain curve, which enables to construct informative damage and failure maps. The applicability of the phenomenological modeling method and the fitting procedure is demonstrated with the tensile test data of some human and animal tissues, such as facial nerves and tendons.

Burn-induced heart failure: lipopolysaccharide binding protein improves burn and endotoxin-induced cardiac contractility deficits.

BACKGROUND: Burn injury is frequently complicated by bacterial infection. Following burn injury, exposure to endotoxin produces a measurable decrease in cardiomyocyte sarcomere contractile function. Lipopolysaccharide-binding protein (LBP) is an acute phase protein that potentiates the recognition of lipopolysaccharide (LPS) by binding to the lipid A moiety of LPS. In this study, we sought to determine the effect of recombinant rat LBP (rLBP) on cardiomyocyte sarcomere function after burn or sham injury in the presence or absence of bacterial endotoxin. METHODS: Rats underwent a full-thickness 30% total body surface area scald or sham burn. At 24 h post-injury, cardiomyocytes were isolated, plated at 50,000 cells/well, and incubated with 50 µg/mL LPS and rLBP or chloramphenicol acetyltransferase (BVCat, an irrelevant control protein produced using the same expression system as rLBP) at concentrations by volume of 1%, 5%, 10%, and 30%. Subsets of cardiomyocytes were incubated with 5% rat serum or 30% rLBP and blocking experiments were conducted using an LBP-like synthetic peptide (LBPK95A). In vitro sarcomere function was measured using a variable rate video camera system with length detection software. RESULTS: Co-culture of burn and sham injury derived cardiomyocytes with high-dose rLBP in the presence of LPS resulted in a significant reduction to the functional impairment observed in peak sarcomere shortening following exposure to LPS alone. LBP-like peptide LBPK95A at a concentration of 20 µg/mL, in the presence of LPS, abolished the ability of 30% rLBP and 5% rat serum to restore peak sarcomere shortening of cardiomyocytes isolated following burn injury to levels of function exhibited in the absence of endotoxin exposure. CONCLUSIONS: In the setting of LPS challenge following burn injury, rLBP at high concentrations restores cardiomyocyte sarcomere contractile function in vitro. Rather than potentiating the recognition of LPS by the cellular LPS receptor complex, rLBP at high concentrations likely results in an inhibitory binding effect that minimizes the impact of endotoxin exposure on cardiomyocyte function following thermal injury.

Cannabidiol in low back pain: scientific rationale for clinical trials in low back pain.

INTRODUCTION: The pooled worldwide prevalence of low-back pain-related presentations in primary care varies between 6.8% and 28.4% in the high-income countries rendering it a major healthcare/economy problem. To best manage this complex bio-psycho-social condition a 360-degree approach is needed, as the psycho-social components are often more important than the scant pathophysiology. Pattern analysis of cannabis users suggested that attempts to alleviate musculo-skeletal pain is often seen as a major drive to use cannabinoids. AREAS COVERED: Unlike NSAIDs/opioids, cannabidiol might directly affect more than one modality of pain signaling/perception. The 2019 guideline of the National Institute for Clinical Excellence recommended further studies with cannabidiol in pain medicine because of its excellent safety profile and presumed therapeutic potential. Therefore, we have researched relevant databases for pharmaco-physiological papers published between 2000 and 2021 to collate evidence in a narrative fashion to determine the clinical rationale for this cannabinoid in low-back pain. EXPERT OPINION: Observational research reported good results with CBD in pain and fear reduction, which are both key factors in low-back pain. Given the paucity of high-quality evidence, further research is needed to determine the efficacy/non-inferiority of CBD in primary/emergency care setting, using multimodal assessment of various patient-reported outcomes.

A retrospective study of bronchoalveolar lavage fluid analysis in barrel racing horses with exercise-induced pulmonary hemorrhage and asthma in Texas from 2016 to 2018.

Exercise-induced pulmonary hemorrhage (EIPH) and asthma in barrel racing horses is a common disease across the United States. Limited information is available on non-infectious respiratory diseases in this population, the interaction between these two diseases, and the occurrence of both EIPH and asthma in the horse. The purpose of this study was to evaluate the bronchoalveolar lavage (BAL) fluid cytological results of barrel racing horses with EIPH, asthma, or both. A retrospective study was conducted using the medical records of horses that presented with cough and decreased athletic performance and BAL results that met the criteria for inclusion. Data from 95 horses were included from a private practice referral hospital in Texas. No statistical difference was found in the frequency of neutrophilia, eosinophilia, or mastocytosis between diagnoses of EIPH, asthma, or concurrent diagnoses of EIPH and asthma. Bronchoalveolar lavage of horses suspected of EIPH is warranted to fully characterize the noninfectious respiratory disease of barrel racing horses.

Effects of Chlorine Dioxide on Oral Hygiene - A Systematic Review and Meta-analysis.

BACKGROUND: Effective and selective oral rinses are required in the daily medical and dental practice. Currently mouthwashes used have substantial side effects. OBJECTIVES: Our aim was to evaluate the efficacy of chlorine dioxide-containing mouthwashes in comparison with other previously established mouth rinses in healthy adults using oral hygiene indices. METHODS: This work was registered in PROSPERO (CRD42018099059) and carried out using multiple databases and reported according to the PRISMA statement. The search terms used were "chlorine dioxide" AND "oral", and only randomised controlled trials (RCTs) were included. The primary outcome was the alteration of the plaque index (PI), while the secondary outcomes were the gingival index (GI) and bacterial counts. For the risk of bias assessment, the Cochrane Risk of Bias Tool was used. Statistical analysis for data heterogeneity was performed by Q-value and I2-tests. RESULTS: 364 articles were found in the databases. After the selection process, only five RCTs were eligible for meta-analysis. Data heterogeneity was low. There were no statistical differences in effectiveness between chlorine dioxide and other effective mouth rinses in PI (0.720±0.119 vs 0.745±0.131; 95%; confidence intervals (CIs): 0.487-0.952 vs 0.489-1.001, respectively) and GI (0.712±0.130 vs 0.745±0.131; 95% CIs: 0.457-0.967 vs 0.489- 1.001, respectively) and also in bacterial counts. CONCLUSION: Chlorine dioxide reduces both plaque and gingival indices and bacterial counts in the oral cavity similar to other routinely used oral rinses, however, the evidence supporting this outcome is very limited. Therefore, further large scale RCTs are needed to decrease the risk of bias.

γ-Aminobutyric Acid and Derivatives Reduce the Incidence of Acute Pain after Herpes Zoster - A Systematic Review and Meta-analysis.

Herpes zoster (HZ) causes considerable pain and distress, and γ-Aminobutyric acid (GABA) and its derivatives are assumed to control this, but the available data are inconsistent. This meta-analysis and systematic review aimed to assess the effectiveness of GABA derivatives in the prevention of acute herpetic pain. The metaanalysis was conducted following the PRISMA guidelines using PICO format, registered in PROSPERO number CRD42018095758. PubMed, Web of Science, Ovid, Scopus, and EMBASE databases were searched. Records were included if they were randomized controlled trials of patients undergoing HZ infection, investigating the effect of GABA derivatives versus placebo in the treatment of HZ pain. Eligible trials were evaluated for the risk of bias. Then data were extracted and analysed. The number of patients with observed presence of pain after treatment was used to calculate odds ratio in a random effect model with the DerSimonian-Laird estimator. The I2 statistic was analysed for heterogeneity. The potential risk of bias was measured using Egger's regression test. The meta-analysis included three randomized controlled trials with a total of 297 patients. The incidence of acute HZ pain events for GABA group was significantly lower compared to placebo group,18/148 vs 44/149, respectively (OR = 0.36; 95% CI = 0.14 to 0.93; Z = 2.11; P = 0.035), Egger's test yielded P = 0.308. In conclusion, the present meta-analysis demonstrates that GABA derivatives reduce the incidence of acute herpetic pain. However, additional, well-designed randomized clinical trials are needed to determine their dose- and time-dependency regarding this symptom.

Towards a European health research and innovation cloud (HRIC).

The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe.

Adverse functions of IL-17A in experimental sepsis.

IL-17A is a proinflammatory cytokine produced by a variety of cells. In the current study, we examined the role of IL-17A in sepsis induced in mice by cecal ligation and puncture (CLP). IL-17A levels, which rose time-dependently in plasma after CLP, were not affected in the absence of alphabeta T cells or neutrophils. In sharp contrast, gammadelta T cell-knockout or gammadelta T cell-depleted mice displayed baseline IL-17A plasma levels after CLP. Neutralization of IL-17A by two different antibodies improved sepsis (survival from approximately 10% to nearly 60%). Unexpectedly, antibody treatment was protective, even when administration of anti-IL-17A was delayed for up to 12 h after CLP. These protective effects of IL-17A blockade were associated with substantially reduced levels of bacteremia together with significant reductions of systemic proinflammatory cytokines and chemokines in plasma. In vitro incubation of mouse peritoneal macrophages with lipopolysaccharide (LPS) in the copresence of IL-17A substantially increased the production of TNF-alpha, IL-1beta, and IL-6 by these cells. These data suggest that, during experimental sepsis, gammadelta T cell-derived IL-17A promotes high levels of proinflammatory mediators and bacteremia, resulting in enhanced lethality. IL-17A may be a potential therapeutic target in sepsis.

Ability of antioxidant liposomes to prevent acute and progressive pulmonary injury.

We recently showed that acute oxidant-related lung injury (ALI) in rats after application of 2-chloroethyl ethyl sulfide (CEES) is attenuated by the airway instillation of antioxidants. We investigated whether intratracheal administration of antioxidant-containing liposomes immediately after instillation of CEES would attenuate short-term as well as long-term (fibrotic) effects of CEES-induced lung injury. In the acute injury model (4 h after injury), N-acetylcysteine (NAC)-containing liposomes were protective and reduced to baseline levels both the lung permeability index and the appearance of proinflammatory mediators in bronchoalveolar lavage fluids from CEES-exposed lungs. Similar results were obtained when rat alveolar macrophages were incubated in vitro with either CEES or lipopolysaccharide in the presence of NAC-liposomes. When lung fibrosis 3 weeks after CEES was quantitated by using hydroxyproline content, liposomes containing NAC or NAC + glutathione had no effects, but liposomes containing alpha/gamma-tocopherol alone or with NAC significantly suppressed the increase in lung hydroxyproline. The data demonstrate that delivery of antioxidants via liposomes to CEES-injured lungs is, depending on liposomal content, protective against ALI, prevents the appearance of proinflammatory mediators in bronchoalveolar fluids, and suppresses progressive fibrosis. Accordingly, the liposomal strategy may be therapeutically useful in CEES-induced lung injury in humans.

Complement-related molecular events in sepsis leading to heart failure.

Despite intensive ongoing research efforts, the mortality of patients with sepsis remains unacceptably high. A significant number of clinical trials have failed to produce sufficient therapeutic strategies despite showing promising results in animal models. So far, many studies have focused on deterioration of the humoral and cellular components of the immune system, the main cause of death in septic patients being multi-organ failure. However, not much is known about the effects of the complement system on parenchymal cells of organs such as the heart. Recently, septic cardiomyopathy has been recognized as one of the major complications during sepsis, often determining the clinical outcome. In this review, we describe molecular events which are thought to be related to cardiac dysfunction during sepsis. A special emphasis will be placed on the complement system, which generates powerful anaphylatoxins (such as C5a) and which has recently been associated with septic cardiomyopathy. Together with the impact on cardiac function of various cytokines we will provide a synopsis of the current knowledge regarding the pathophysiology underlying cardiac failure during sepsis with a special emphasis on C5a and C5aR.

Topical p38 MAPK inhibition reduces bacterial growth in an in vivo burn wound model.

BACKGROUND: Although the inflammatory response is a prerequisite for wound healing, excessive activation of the innate immune system can induce epithelial cell damage and apoptosis, which may further compromise dermal integrity. In a noninfectious burn wound model, we previously demonstrated that topical inhibition of p38 MAPK, an important inflammatory signaling pathway, attenuated epithelial cell damage and apoptosis. We now question whether attenuating local inflammation would weaken bacterial wound resistance and compromise host defense. METHODS: Rats received 30% total body surface area burn, and the wound was treated with topical application of a p38 MAPK inhibitor or vehicle. At 24 hours after injury, burn wounds were inoculated with Pseudomonas aeruginosa. At 48 hours postinjury, animals were sacrificed, and the burn wound was analyzed. RESULTS: Inoculating burn wounds induced significant bacterial growth. Dermal inflammatory changes were markedly accentuated in the inoculated animals. Topical p38 MAPK inhibition reduced the proinflammatory cytokine expression in the burn wounds and neutrophil sequestration with or without bacterial inoculation. Interestingly, the bacterial wound growth was significantly attenuated in animals treated with topical p38 MAPK inhibitor. CONCLUSIONS: Topical p38 MAPK inhibition attenuated wound inflammation without interfering with bacterial host defense. Attenuation of excessive burn wound inflammatory signaling may prevent secondary damage of the dermal barrier and reduce the growth of opportunistic pathogens.

New insights into cellular mechanisms during sepsis.

Despite intensive ongoing research efforts, the mortality of patients with sepsis remains unacceptably high. Clinical trials emerging from promising results in animal models have mostly failed to deliver sufficient treatment strategies so far. Many studies investigating the underlying mechanisms of sepsis have focused on deterioration of the humoral and cellular components of the immune system. However, in addition to septic shock, the main cause of death in septic patients is multiorgan failure. So far, not much is known about the effects of a dysregulated immune system as seen in sepsis on parenchymal cells of end organs. Studies on the interaction of the complement system and kidney as well as liver cells resulted in interesting yet still inconclusive data. In this review, we provide new insights into mechanisms during sepsis based on recent findings.

Topical p38MAPK inhibition reduces dermal inflammation and epithelial apoptosis in burn wounds.

Thermal injury induces dermal inflammatory and proapoptotic signaling. These phenomena extend burn wound size and trigger a systemic inflammatory response, factors known to adversely affect outcomes. p38MAPK is known to trigger inflammatory responses and induce epithelial proapoptotic genes. We hypothesize that topical p38MAPK inhibition will attenuate excessive inflammatory and apoptotic signaling and reduce dermal tissue loss. Rats were given a 30% total body surface area partial thickness burn or sham injury. Some of the animals were treated with a p38MAPK inhibitor or vehicle, which was applied directly to the wound. Dermal inflammation was investigated with enzyme-linked immunosorbent assay, reverse transcriptase polymerase chain reaction, myeloperoxidase assay, and Evans blue extravasation. Apoptotic changes were detected using terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and Caspase-3 in situ staining. Burn injury activated dermal p38MAPK and induced a significant rise in dermal IL-6, TNF-alpha, and IL-1beta expression. Neutrophil sequestration, microvascular damage, and hair follicle apoptosis were significantly elevated after injury. Topical p38MAPK inhibition significantly attenuated downstream dermal p38MAPK targets, proinflammatory cytokine expression, neutrophil sequestration, and microvascular injury. A significant reduction in hair follicle apoptosis was seen. This study demonstrates the attenuation of burn-induced cellular stress by topical application of p38MAPK inhibitors. Blunting early excessive inflammatory signaling may be an efficient strategy to improve patient outcomes after burn injury.

Ruptured Cystic Mesothelioma Diagnosed after Blunt Trauma; Case Report and Literature Review.

The majority of blunt trauma is secondary to motor vehicle crashes,especially in those wearing seatbelts or sitting in the front or passenger seat location.Hollow viscus gastrointestinal injuries occur more frequently in small bowel, followed by colorectal, duodenum, stomach and appendix. A 25-year-old male presents after being involved in a motor vehicle accident. Initialworkup was significant for moderate amount of pelvic free fluid and curvilinear,cysticlike structures in the pelvis. He subsequently developed peritonitis and underwentdiagnostic laparoscopy, which revealed multiple cystic nodules arising from theperitoneum. Pathology demonstrated benign cystic mesothelioma (BCM). BCM is a very rarecondition of mesotheliallined, variably sized, fluidfilled cysts that arises from theserous, pericardial or peritoneal lining. Due to the scarcity of cases, its management and prognosis are not fully established. This singular case highlights the necessity for a clinician to have a widedifferential forunusual causes of free pelvic fluid after blunt abdominaltrauma.

Harmful and protective roles of neutrophils in sepsis.

The current studies demonstrate protective and harmful effects of neutrophils (PMN) during experimental sepsis after cecal ligation and puncture (CLP). It is known that CLP induces signaling defects in blood PMN. When PMN were depleted 12 h after CLP, there were dramatic reductions in levels of bacteremia, evidence for reduced liver and renal dysfunction, sharp reductions in serum levels of cytokines (IL-1beta, IL-6, IL-10, TNF-alpha, and IL-2), and improved survival. In contrast, PMN depletion before CLP resulted in substantial increases in bacteremia and no evidence for attenuation of liver and renal failure dysfunction. These data suggest that at the onset of sepsis, PMN are important in regulating the levels of bacteremia, whereas after the onset of sepsis, as they lose innate immune functions, their presence is associated with higher levels of bacteremia and intensified organ dysfunction.

Varicella-zoster virus infection of human mononuclear cells.

Varicella-zoster virus (VZV) DNA was detected in mononuclear cells (MNC) of 7 humans with acute zoster 1-23 days after the onset of skin lesions. To further study the interaction of VZV with human MNC, cells obtained from seropositive normal donors were infected with VZV and analyzed for the presence of viral DNA and proteins. VZV-DNA was detected in T, B, and OKM 1 (monocyte-macrophage) positive cells, and virus-specific proteins were demonstrated by indirect immunofluorescence and immunoprecipitation. Hybridization studies revealed that VZV-DNA did not replicate in human MNC.