Advances in macrophage metabolic reprogramming in myocardial ischemia-reperfusion.

Acute myocardial infarction (AMI) is the leading cause of death worldwide, and reperfusion therapy is a critical therapeutic approach to reduce myocardial ischemic injury and minimize infarct size. However, ischemia/reperfusion (I/R) itself also causes myocardial injury, and inflammation is an essential mechanism by which it leads to myocardial injury, with macrophages as crucial immune cells in this process. Macrophages are innate immune cells that maintain tissue homeostasis, host defence during pathogen infection, and repair during tissue injury. During the acute phase of I/R, M1-type macrophages generate a pro-inflammatory milieu, clear necrotic myocardial tissue, and further recruit mononuclear (CCR2+) macrophages. Over time, the reparative (M2 type) macrophages gradually became dominant. In recent years, metabolic studies have shown a clear correlation between the metabolic profile of macrophages and their phenotype and function. M1-type macrophages are mainly characterized by glycolytic energy supply, and their tricarboxylic acid (TCA) cycle and mitochondrial oxidative phosphorylation (OXPHOS) processes are impaired. In contrast, M2 macrophages rely primarily on OXPHOS for energy. Changing the metabolic profile of macrophages can alter the macrophage phenotype. Altered energy pathways are also present in macrophages during I/R, and intervention in this process contributes to earlier and greater M2 macrophage infiltration, which may be a potential target for the treatment of myocardial I/R injury. Therefore, this paper mainly reviews the characteristics of macrophage energy metabolism alteration and phenotypic transition during I/R and its mechanism of mediating myocardial injury to provide a basis for further research in this field.

Toxicity and bioactivity of cobalt nanoparticles on the monocytes.

OBJECTIVE: To explore the toxicity and biological activity of cobalt nanoparticles on the osteoclasts. Analyze the relationship between cobalt nanoparticles and osteolysis. METHODS: Monocyte-macrophages (RAW 264.7) was cultured in vitro, osteoclast-like cells were induced by lipopolysaccharides (LPS). After RAW 264.7 was induced for 24 h, Methyl Thiazolium Tetrazolium (MTT) biological toxicity test of osteoclast-like cell was preceded using Cobalt nanoparticles (set 4 concentrations: 10, 20, 50, 100 µM) and cobalt chloride (set 4 concentrations: 10, 20, 50, 100 µM) at 2, 4, 8, 24 and 48 h respectively. The relative expression of mRNA of CA II and Cat K after RAW 264.7 induction was determined by Q-PCR. RESULTS: mRNA relative expression of CA II, Cat K were reduced at multiple concentrations both cobalt nanoparticles and cobalt chloride, and was time and concentration dependent, cobalt nanoparticles are more significant than cobalt chloride group. But when the cobalt nanoparticles concentration is in 10-50 µM, the mRNA relative expression of CA II, Cat K increased. CONCLUSION: Cobalt nanoparticles have biological toxicity. At multiple concentrations, the differentiation and proliferation of osteoclasts was inhibited, but when the concentration of cobalt nanoparticles is in 10-50 µM, it has been strengthened.

Comparison of complications and results of early versus delayed surgery for Gartland type III supracondylar humeral fractures in pediatric patients.

OBJECTIVE: To investigate the effect of timing of surgery on clinical results and perioperative complications in pediatric patients with Gartland III type supracondylar humeral fractures without neurovascular compromise. METHODS: Eighty-six consecutive children treated surgically at our hospital from April 2005 to June 2007 for displaced supracondylar humeral fractures were reviewed. All these patients were treated by the same group of doctors. The children were divided into two groups: early if treated within 12 hours after injury and delayed if treated later than that. Perioperative complications and clinical results, especially for open surgery, were compared between the two groups. RESULTS: Forty pediatric patients underwent surgery in the early group and 46 in the delayed group. There were no significant differences between the two groups in perioperative complications such as pin tract infection, iatrogenic nerve injury, compartment syndrome and conversion to open surgery. For open surgery, both the clinical results and perioperative complications were not affected by delaying for more than 12 hours after injury. However, blood loss and operation time were greater in the early than in the delayed group, possibly due to relatively more edema. CONCLUSION: Delay in surgery, regardless of whether it is closed or open, for more than 12 hours after injury does not influence the perioperative complications and clinical results for displaced supracondylar humeral fractures in children. However early open reduction and pinning may increase intra-operative blood loss and take longer.

[Surgical treatment for open dislocation of talus].

OBJECTIVE: To evaluate the clinical effects of surgical treatment for open dislocation of talus. METHODS: From June 2001 to July 2008,the complete data of 11 patients with open dislocations of talus were retrospectively analyzed, including 8 males and 3 females with an average age of 39.5 years (ranged 19 to 52). According to Gustilo typing, type I was in 2 cases, type II in 6 cases, type III A in 2 cases, type III B in 1 case. Five cases were tibial astragaloid joint dislocation in which 3 cases associated with subtalar joint dislocation, 4 cases were subtalar joint dislocation and 2 cases were total dislocation of talus. Among them, 8 dislocations associated with talus fractures. All patients were treated with debridement, open reduction, internal fixation with K-wires or screws and external fixation with plaster or external fixator within 8 hours after injury. External fixations were removed at 6 weeks after operation. Partial weight bearing was permitted only when X-rays indicated bony healing. Clinical effects were evaluated according to AOFAS system and X-ray films during follow-up. RESULTS: The mean time of follow-up was 13.8 months(ranged 10 to 15 months). Eight patients with fractures obtained bone healing in 4-7 months with an average of 4.3 months. No infection of wound or deep tissue was found. At final follow-up, talus necrosis was in 2 cases and traumatic arthritis was in 2 cases. The AOFAS score was 71.3 +/- 8.6, among the total, the pain, function, alignment was respectively (32.4 +/- 7.1), (31.0 +/- 15.7), (7.6 +/- 2.3) scores. CONCLUSION: Complete debridement may avoid infection in treating open dislocation of talus, early reduction and fixation is a key point during treatment.