Intraoperative prostaglandin E1 improves antimicrobial and inflammatory responses in alveolar immune cells

Effects of propofol on macrophage activation and function in diseases

Macrophages work with monocytes and dendritic cells to form a monocyte immune system, which constitutes a powerful cornerstone of the immune system with their powerful antigen presentation and phagocytosis. Macrophages play an essential role in infection, inflammation, tumors and other pathological conditions, but these cells also have non-immune functions, such as regulating lipid metabolism and maintaining homeostasis. Propofol is a commonly used intravenous anesthetic in the clinic. Propofol has sedative, hypnotic, anti-inflammatory and anti-oxidation effects, and it participates in the body’s immunity. The regulation of propofol on immune cells, especially macrophages, has a profound effect on the occurrence and development of human diseases. We summarized the effects of propofol on macrophage migration, recruitment, differentiation, polarization, and pyroptosis, and the regulation of these propofol-regulated macrophage functions in inflammation, infection, tumor, and organ reperfusion injury. The influence of propofol on pathology and prognosis via macrophage regulation is also discussed. A better understanding of the effects of propofol on macrophage activation and function in human diseases will provide a new strategy for the application of clinical narcotic drugs and the treatment of diseases.

Essential Fatty Acids and Their Metabolites in the Pathobiology of Inflammation and Its Resolution

Arachidonic acid (AA) metabolism is critical in the initiation and resolution of inflammation. Prostaglandin E2 (PGE2) and leukotriene B4/D4/E4 (LTB4/LD4/LTE4), derived from AA, are involved in the initiation of inflammation and regulation of immune response, hematopoiesis, and M1 (pro-inflammatory) macrophage facilitation. Paradoxically, PGE2 suppresses interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) production and triggers the production of lipoxin A4 (LXA4) from AA to initiate inflammation resolution process and augment regeneration of tissues. LXA4 suppresses PGE2 and LTs' synthesis and action and facilitates M2 macrophage generation to resolve inflammation. AA inactivates enveloped viruses including SARS-CoV-2. Macrophages, NK cells, T cells, and other immunocytes release AA and other bioactive lipids to produce their anti-microbial actions. AA, PGE2, and LXA4 have cytoprotective actions, regulate nitric oxide generation, and are critical to maintain cell shape and control cell motility and phagocytosis, and inflammation, immunity, and anti-microbial actions. Hence, it is proposed that AA plays a crucial role in the pathobiology of ischemia/reperfusion injury, sepsis, COVID-19, and other critical illnesses, implying that its (AA) administration may be of significant benefit in the prevention and amelioration of these diseases.

Beneficial role of bioactive lipids in the pathobiology, prevention, and management of HBV, HCV and alcoholic hepatitis, NAFLD, and liver cirrhosis: A review

It has been suggested that hepatitis B virus (HBV)- and hepatitis C virus (HCV)-induced hepatic damage and cirrhosis and associated hypoalbuminemia, non-alcoholic fatty liver disease (NAFLD), and alcoholic fatty liver disease (AFLD) are due to an imbalance between pro-inflammatory and anti-inflammatory bioactive lipids. Increased tumour necrosis factor (TNF)-α production induced by HBV and HCV leads to a polyunsaturated fatty acid (PUFA) deficiency and hypoalbuminemia. Albumin mobilizes PUFAs from the liver and other tissues and thus may aid in enhancing the formation of anti-inflammatory lipoxins, resolvins, protectins, maresins and prostaglandin E1 (PGE1) and suppressing the production of pro-inflammatory PGE2. As PUFAs exert anti-viral and anti-bacterial effects, the presence of adequate levels of PUFAs could inactivate HCV and HBV and prevent spontaneous bacterial peritonitis observed in cirrhosis. PUFAs, PGE1, lipoxins, resolvins, protectins, and maresins suppress TNF-α and other pro-inflammatory cytokines, exert cytoprotective effects, and modulate stem cell proliferation and differentiation to promote recovery following hepatitis, NAFLD and AFLD. Based on this evidence, it is proposed that the administration of albumin in conjunction with PUFAs and their anti-inflammatory products could be beneficial for the prevention of and recovery from NAFLD, hepatitis and cirrhosis of the liver. NAFLD is common in obesity, type 2 diabetes mellitus, and metabolic syndrome, suggesting that even these diseases could be due to alterations in the metabolism of PUFAs and other bioactive lipids. Hence, PUFAs and co-factors needed for their metabolism and albumin may be of benefit in the prevention and management of HBV, HCV, alcoholic hepatitis and NAFLD, and liver cirrhosis.

Misoprostol modulates cytokine expression through a cAMP pathway: Potential therapeutic implication for liver disease

Dysregulated cytokine metabolism plays a critical role in the pathogenesis of many forms of liver disease, including alcoholic and non-alcoholic liver disease. In this study we examined the efficacy of Misoprostol in modulating LPS-inducible TNFα and IL-10 expression in healthy human subjects and evaluated molecular mechanisms for Misoprostol modulation of cytokines in vitro. Healthy subjects were given 14day courses of Misoprostol at doses of 100, 200, and 300μg four times a day, in random order. Baseline and LPS-inducible cytokine levels were examined ex vivo in whole blood at the beginning and the end of the study. Additionally, in vitro studies were performed using primary human PBMCs and the murine macrophage cell line, RAW 264.7, to investigate underlying mechanisms of misoprostol on cytokine production. Administration of Misoprostol reduced LPS inducible TNF production by 29%, while increasing IL-10 production by 79% in human subjects with no significant dose effect on ex vivo cytokine activity; In vitro, the effect of Misoprostol was largely mediated by increased cAMP levels and consequent changes in CRE and NFκB activity, which are critical for regulating IL-10 and TNF expression. Additionally, chromatin immunoprecipitation (ChIP) studies demonstrated that Misoprostol treatment led to changes in transcription factor and RNA Polymerase II binding, resulting in changes in mRNA levels. In summary, Misoprostol was effective at beneficially modulating TNF and IL-10 levels both in vivo and in vitro; these studies suggest a potential rationale for Misoprostol use in ALD, NASH and other liver diseases where inflammation plays an etiologic role.

The Effects of Prostaglandin E1 on Interleukin-6, Pulmonary Function and Postoperative Recovery in Oesophageetomised Patients

The inflammatory reactions and tissue response after oesophagectomy are leading causes of postoperative morbidity and mortality. We evaluated the effects of intraoperative infusion of prostaglandin E1 (PGE1) on interleukin-6 (IL-6) levels, (A-a) DO2, pulmonary function and complications. This randomised double-blind clinical trial study was performed on patients undergoing transthoracic oesophagectomy due to cancer. Thirty patients were randomly allocated to two groups: the PGE1 group (infusion of PGE1, 20 ng.kg−1.min−1) and a placebo group (infusion of normal saline 0.9%). The infusion was started before induction of anaesthesia and continued until the end of the operation. The groups were comparable in basic characteristics and preoperative pulmonary function. Patients in the PGE1 group were discharged significantly earlier from the intensive care unit (72±9 vs 83±17 hours) and hospital (13±4 vs 18±8 days) (P=0.04 and 0.03, respectively). The (A-a) DO2 was significantly less in the PGE1 group at 12 and 24 hours after the operation (P=0.001, P=0.003, respectively). Postoperatively, IL-6 levels were significantly higher in the placebo group than in the PGE1 group. There were no differences in the forced expiratory volume in the first second or forced vital capacity. The findings indicate that infusion of PGE1 attenuates the increase in serum levels of IL-6 in patients undergoing esophagectomy and improves the (A-a) DO2. Stays in the intensive care unit and hospital were shorter in the PGE1 group. However, there were no differences in pulmonary complications.

The Effects of LASIK on the Ocular Surface

Laser in situ keratomileusis (LASIK) can affect corneal sensation, aqueous tear production, wound healing, and the incidence of corneal erosions. Virtually all patients experience dry eye at least transiently after LASIK. Because intact corneal sensation drives tear production, denervation associated with the LASIK procedure is the most significant cause of post-LASIK dry eye. To prevent symptomatic postoperative dry eye, it is crucial to identify and treat pre-existing dry eye before surgery. This review addresses the pathophysiology and management of dry eye, as well as the relationship between LASIK and corneal erosions, and suggests intra- and post-operative management techniques to minimize complications and maximize the stability of the ocular surface. Contraindications to LASIK and alternative refractive surgical procedures are discussed.