Mai M. Abdelhafez

Background: Currently, the duration of tourniquet time in total knee arthroplasty is chosen by the surgeons and varies between 0 and 120 min. Studies evaluating the effect of tourniquet time in this surgery are heterogeneous, and there is limited information on molecular/complement profiling. The purpose of this study was, therefore, to determine whether the duration of tourniquet-induced limb ischemia during total knee arthroplasty influences reperfusion injury, resulting in pain, swelling, and the release of pro-inflammatory markers. Methods: In 40 patients undergoing total knee arthroplasty, a tourniquet was applied for up to 30 min (group A, short tourniquet) or 90–120 min (group B, long tourniquet). Postoperative pain and swelling served as primary outcome parameters. The levels of pro- and anti-inflammatory markers before surgery and 4 h, 24 h, and 48 h after surgery were used as secondary outcome parameters for exploratory testing. Results: There were no differences in numeric rating pain scale (NRS) scores and calf circumference between groups A and B. Patients in group B required patient-controlled intravenous analgesia more frequently than group A patients (47% versus 5%, group B vs. group A, p < 0.0001). In group B, a significantly higher increase in C3a and MIG levels between 4 h and 48 h, and a significantly higher increase for MIG and M-CSF between 24 h and 48 h, were observed. Conclusions: Tourniquet times between 90 and 120 min were not associated with higher pain levels or more swelling, but an increased need for intravenous analgesia and a higher increase in pro-inflammatory markers. This might be a consequence of a more pronounced ischemia/reperfusion injury with tourniquet times longer than 90 min.

Background: Currently, the duration of tourniquet time in total knee arthroplasty is chosen by the surgeons and varies between 0 and 120 minutes. Studies evaluating the effect of tourniquet time in this operation are lacking. The purpose of this study was, therefore, to determine whether the duration of tourniquet-induced limb ischemia during total knee arthroplasty influences reperfusion injury, resulting in pain, swelling and the release of proinflammatory markers. Methods: In 40 patients undergoing total knee arthroplasty, tourniquet was applied for up to 30 minutes (group A, short tourniquet) or 90-120 minutes (group B, long tourniquet). Postoperative pain and swelling served as primary outcome parameters. The levels of pro- and anti-inflammatory markers (D-dimers, C3a, C5a, TAT, fetuin-A, PAI-I/tPA complexes, CK-MM, IP10, M-CSF, MIG, MIP-1α, and sC5b9) before surgery and 4 hours, 24 hours and 48 hours after surgery, were used as secondary outcome parameters. Results: Patients in group B, with the long tourniquet time, required patient-controlled intravenous analgesia more frequently than group A patients (47% versus 5%, group B vs. group A, p < 0.0001). However, there were no differences in numeric rating pain scale (NRS) scores and calf circumference between groups A and B. In group B, a significantly higher increase of C3a levels between 4 h and 48 h, a significantly higher increase for MIG between 4 h and 48 h as well as 24 h and 48 h, and a significantly higher increase in M-CSF levels between 24 h and 48 h were observed when compared to group A. Conclusions: Tourniquet times between 90 and 120 minutes, despite currently being accepted in the clinical setting, were associated with an increased need for intravenous analgesia and higher increase of the pro-inflammatory markers C3a, MIG, and M-CSF, suggesting a more pronounced ischemia/reperfusion injury with tourniquet times longer than 90 minutes.

The present study explores the metabolic profiling and molecular wound-healing mechanisms of Echinacea purpurea (L.) Moench (EP) flowers aqueous (AE) and ethanol (EE) extracts in an excision wound-healing model. Metabolic profiling of the extracts was investigated using UHPLC-ESI-TOF–MS and molecular networking. Antioxidant activity was carried out using the DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging method and FRAP (ferric reducing antioxidant power). Carboxy methylcellulose gels of 5 and 10% of both aqueous (AE) and ethanol (EE) extracts were prepared. The wounds were explored macroscopically, histologically, and immunohistochemically. The UHPLC-ESI-TOF–MS method enabled the identification of 3 organic acids, 14 phenolic acids, 3 phenylethanoid glycosides, and 11 flavonoids from EP extracts. EE had significant antioxidant activity compared to AE. The EP treated wounds healed faster. The EE succeeded in improving healing properties and controlling the inflammatory response by reducing IL-6 and increasing IL-10 expression and enhancing angiogenesis and remodeling via increased NF-κB, TGF-β, VEGF, CD31 expression and α-SMA and collagen deposition. It is worth mentioning that the EE groups also showed improvement in the histopathological examination in a dose-dependent manner. The effectiveness of EE in wound-healing may be attributed to its higher content of polyphenols which also made the antioxidant potential of the EE and its capacity to donate electrons higher than that of AE. This study scientifically enables the understanding of the molecular mechanisms Echinacea purpurea extract in wound healing via modulating skin inflammatory response and indicates the potential usefulness of EP ethanol extract for wound healing.

White, green, and oolong teas are produced from the tea plant (Camellia sinensis (L.) Kuntze) and are reported to have anti-obesity and hypolipidemic effects. The current study aims to investigate the anti-obesity effects of a tea mixture nano-formulation by targeting the AMPK/Sirt-1/GLUT-4 axis in rats. In vitro lipase and α-amylase inhibition assays were used to determine the active sample, which was then incorporated into a nanoparticle formulation subjected to in vivo anti-obesity testing in rats by measuring the expression level of different genes implicated in adipogenesis and inflammation using qRT-PCR. Moreover, metabolomic analysis was performed for each tea extract using LC/ESI MS/MS coupled to chemometrics in an attempt to find a correlation between the constituents of the extracts and their biological activity. The in vitro pancreatic lipase and α-amylase inhibition assays demonstrated more effective activity in the tea mixture than the standards, orlistat and acarbose, respectively, and each tea alone. Thus, the herbal tea mixture and its nanoparticle formulation were evaluated for their in vivo anti-obesity activity. Intriguingly, the tea mixture significantly decreased the serum levels of glucose and triglycerides and increased the mRNA expression of GLUT-4, P-AMPK, Sirt-1, and PPAR-γ, which induce lipolysis while also decreasing the mRNA expression of TNF-α and ADD1/SREBP-1c, thereby inhibiting the inflammation associated with obesity. Our study suggests that the tea mixture nano-formulation is a promising therapeutic agent in the treatment of obesity and may also be beneficial in other metabolic disorders by targeting the AMPK/Sirt-1/Glut-4 pathway.

Inhibiting thrombosis without generating bleeding risks is a major challenge in medicine. A promising solution may be the inhibition of coagulation factor XII (FXII), because its knock-out or inhibition in animals reduced thrombosis without causing abnormal bleeding. Herein, we have engineered a macrocyclic peptide inhibitor of activated FXII (FXIIa) with sub-nanomolar activity (K_i = 370 ± 40 pM) and a high stability (t_1/2 > 5 days in plasma), allowing for the preclinical evaluation of a first synthetic FXIIa inhibitor. This 1899 Da molecule, termed FXII900, efficiently blocks FXIIa in mice, rabbits, and pigs. We found that it reduces ferric-chloride-induced experimental thrombosis in mice and suppresses blood coagulation in an extracorporeal membrane oxygenation (ECMO) setting in rabbits, all without increasing the bleeding risk. This shows that FXIIa activity is controllable in vivo with a synthetic inhibitor, and that the inhibitor FXII900 is a promising candidate for safe thromboprotection in acute medical conditions.

Key Points: Repertoire analysis by microarray technology constitutes a powerful tool to evaluate immune system failure in PADs.

Myocardial ischemia reperfusion (I/R) injury contributes to almost half of the necrotic area after myocardial infarction. To date there is no approved drug to prevent or reduce myocardial I/R injury. The study and understanding of the pathophysiological mechanisms of myocardial I/R injury is essential to develop successful treatments. Large animal experiments are an important step in translational methods. The porcine model of acute myocardial infarction has been established and described by ourselves and others. We aimed to further improve the value of the model by focusing in detail on the sampling techniques for use in future experiments. Furthermore, we emphasize small but important steps that can affect the quality of the final results. To mimic the clinical situation of myocardial I/R injury, a percutaneous coronary intervention (PCI) catheter was inserted into the left anterior descending coronary artery (LAD) of an anesthetized pig. °°°This model mimics acute myocardial infarction and PCI treatment in humans with the possibility of accurately determining the area at risk as well as the necrotic- and viable ischemic tissue. Here the model was used to investigate the effect of a bicyclic peptide inhibitor of FXIIa. The model can also be modified to allow longer reperfusion times to study later effects of myocardial infarction.