Background Mortality and morbidity of acute myocardial infarction remains high. Intravenous magnesium started early after the onset of myocardial infarction is a promising adjunctive treatment that may limit infarct size, prevent serious arrhythmias, and reduce mortality. Several earlier trials and meta-analyses demonstrated a mortality rate reduction with magnesium treatment, but one mega trial found no benefit. Objective To examine the effect of intravenous magnesium versus control on early mortality and morbidity, stratified by time since onset of symptoms (lt;6 hours, 6+ hours), use of thrombolysis (used, not used), dose of magnesium used (lt;75 mmol, 75+ mmol). Search strategy We search the Cochrane controlled trial register (CCTR) of Cochrane Library, Medline and Embase. We also search Chinese Biomedical Disk (CBM disk) to identify the Chinese trials. Each database will be searched from its starting date to the first-half year of 2002. Selection criteria All randomized controlled trials that compared intravenous magnesium with placebo in the presence or absence of fibrolytic therapy in addition to routine treatment are eligible if they reported mortality and clinical events within 35 days of onset, regardless of language. Methods of review A data abstraction form will be specifically developed to extract information from the eligible articles. The quality assessment of RCT will be focused on method of treatment assignment, blinding of participants and investigators, control of selection bias after treatment assignment. The selection of studies, data extraction and assessment of methodological quality will be performed independently by two reviewers. Disagreements will be resolved through discussion, when necessary, in consultation with a third reviewer. Publication bias, heterogeneity and sensitivity analysis will be performed. The odds ratio (OR) will be used to pooling the effect if appropriate.
Objective To evaluate the safety and efficacy of potassium and magnesium supplement with potassium aspartate and magnesium aspartate injection in gastrointestinal surgery patients during absolute fasting．Methods A multicenter randomized controlled clinical trial was conducted in 111 patients after gastrointestinal surgery. For trial group，56 patients were given potassium aspartate and magnesium aspartate injection （Panangin®） in half of the total potassium replenished dose and the rest half of the potassium replenished dose was given in 10% potassium chloride injection．For control group，55 patients were given 10% potassium chloride injection for the total dose of potassium replenished．Such treatments maintained five consecutive days after surgical operation．Clinical observations were performed until patients were discharged from the hospitals．Results Before the intervention，there were no significant differences for the baseline between two groups （P＞0.05）．There was no significant difference for the serum potassium level between two groups （P＞0.05） after intervention．The amount of urinary potassium （mmol/24 h） for patients in the trial group was significantly lower than that in the control group during treatment after operation．The serum magnesium level of control group was much lower than that of control group （P＜0.05）. In the clinical observation process，no drug-related adverse event was observed．Conclusions The supplementary effect of potassium and magnesium for potassium aspartate and magnesium aspartate injection in patients with gastrointestinal surgery during absolute fasting is significant，and superior to potassium chloride injection for potassium supplement．Potassium aspartate and magnesium aspartate injection is a safe and appropriate choice for patients with potassium depletion．
Focusing on the poor mechanical strength of porous bioceramics bone scaffold, and taking into account of the good mechanical properties of biodegradable magnesium alloy, we proposed a novel method to fabricate magnesium alloy/bioceramics composite bone scaffold with stereolithography double channels. Firstly, a scaffold structure without mutually connected double channels was designed. Then, an optimized bioceramics scaffold was fabricated according to stereolithography and gel-casing. Molten AZ31 magnesium alloy was perfused into the secondary channel of scaffold by low-pressure casting, and magnesium alloy/bioceramics composite bone scaffold was obtained when magnesium alloy was solidified. The compression test showed that the strength of bioceramics scaffold with only one channel and without magnesium alloy was (9.76±0.64) MPa, while the strength of magnesium alloy/bioceramics composite scaffold with double channels was (17.25±0.88) MPa. It can be concluded that the magnesium alloy/bioceramics composite is obviously able to improve the scaffold strength.
ObjectiveTo systematically review the clinical efficacy of potassium magnesium aspartate in prevention of arrhythmia after cardiac heart surgery. MethodsSearching PubMed, MEDLINE, EMbase, The Cochrane Library (Issue 5, 2014), CNKI, VIP and WanFang Data to collect randomized controlled trials (RCTs) about the clinical efficacy of potassium magnesium aspartate in prevention of arrhythmia after cardiac heart surgery from the date of establishment of the databases to May 2014. Literature screening according to the inclusion and exclusion criteria, data extraction and methodological quality assessment of the included studies were completed by two reviewers independently. Meta-analysis was then conducted by RevMan 5.2 software. ResultsA total of nine RCTs involving 825 patients were enrolled. The results of meta-analysis indicated that: compared with the control group, timely giving supplement of potassium magnesium aspartate before and after surgery significantly reduced the incidences of arrhythmia (OR=0.25, 95%CI 0.09 to 0.69, P=0.008), premature beats (OR=0.08, 95%CI 0.03 to 0.23, P < 0.000 01), tachycardia (OR=0.29, 95%CI 0.17 to 0.49, P < 0.000 01) and 24 h low cardiac output (OR=0.27, 95%CI 0.10 to 0.72, P=0.009); and increased auto-resuscitation rates (OR=12.16, 95%CI 4.82 to 30.68, P < 0.000 01), with significant differences. However, the two groups were alike in the incidences of atrial fibrillation (OR=0.05, 95%CI-0.16 to 0.05, P=0.34) and ventricular fibrillation (OR=1.24, 95%CI 0.73 to 2.13, P=0.43). ConclusionPotassium magnesium aspartate is effective in prevention of arrhythmias after cardiac surgery, and protective to the myocardium. However, compared with conventional treatment it cannot significantly decrease the incidences of atrial fibrillation and ventricular fibrillation. Due to the limited quantity and quality of the included studies, more multi-centre high quality RCTs with large sample size are needed to verify the above conclusion.
An oxide ceramic coating can be formed on the surface of magnesium alloy by micro-arc oxidation so that the corrosion resistance of the magnesium alloy can be enhanced. In this paper, a general overview of the surface treatment of micro-arc oxidation on the surface of magnesium alloy is presented, the related research on the treatment of several kinds of magnesium alloys is introduced in detail, and a brief introduction of biological activity of magnesium alloy due to micro-arc oxidation is given. Finally, the technical advantages and existing problems are summarized.
ObjectiveTo investigate the mechanism of magnesium sulfate in protecting rabbit cartilage by initiating autophagy.MethodsTwenty-four adult female New Zealand rabbits were used to prepare post-traumatic osteoarthritis (PTOA) models by anterior cruciate ligament transection. Then, the PTOA models were randomly divided into PTOA group, distilled water group, and magnesium sulfate group, with 8 rabbits in each group. Immediately after operation, the distilled water group and the magnesium sulfate group were injected with 0.5 mL distilled water and 20 mmol/L magnesium sulfate solution in the joint cavity 3 times a week for 4 weeks, respectively. The PTOA group was not treated. The general condition of the animals was observed after operation. After 4 weeks, the expressions of tumor necrosis factor α (TNF-α) and collagen typeⅡ in the joint fluid and the expression of collagen type Ⅱ in venous blood were detected by ELISA assay. The protein expressions of transient receptor potential channel vanilloid 5 (TRPV5) and microtubule associated protein 1 light chain 3 (LC3; LC3-Ⅱ/LC3-Ⅰ) in femoral cartilage were detected by Western blot. The mRNA expressions of interleukin 1β (IL-1β), TNF-α, matrix metalloproteinases 3 (MMP-3) in synovial tissue and collagen type Ⅱ, Aggrecan (AGN), SOX9 in cartilage tissue were detected by real-time fluorescence quantitative PCR. Cartilage tissue sections were stained with HE staining, Masson staining, and Alcian blue staining and scored according to the modified histological osteoarthritis (OA) score.ResultsAll animals survived until the experiment was completed. Compared with the other two groups, the expression of TNF-α in joint effusion and collagen type Ⅱ in joint effusion and venous blood were decreased in magnesium sulfate group; the protein expression of TRPV5 decreased, and the ratio of LC3-Ⅱ/LC3-Ⅰ increased significantly; the mRNA expressions of IL-1β, TNF-α, and MMP-3 in synovial tissue were decreased, and the mRNA expressions of collagen type Ⅱ, AGN, and SOX9 in cartilage tissue were increased; OA scores also decreased significantly. All differences were statistically significant (P<0.05). There was no significant difference in the above indicators between the PTOA group and the distilled water group (P>0.05).ConclusionIntra-articular injection of magnesium sulfate can reduce intra-articular inflammation, reduce the loss of collagen type Ⅱ and AGN, and is beneficial to cartilage regeneration in rabbits. The mechanism may be related to the initiation of chondroautophagy by inhibiting the calcium channel TRPV5.
Objective To investigate the safety and efficacy of a new biodegradable magnesium internal fixation screw for vascularized iliac bone flap grafting in treatment of osteonecrosis of the femoral head (ONFH). Methods Patients with ONFH admitted between July 2020 and February 2021 were selected as the research objects, and 20 patients (20 hips) met the selection criteria and were included in the study. The patients were divided into two groups (n=10) by central random method. The iliac bone flap was fixed with a new biodegradable magnesium internal fixation screw in the trial group, and the iliac bone flap was wedged directly in the control group. There was no significant difference (P>0.05) in gender, age, and side, type, Association Research Circulation Osseous (ARCO) stage, and disease duration of ONFH between the two groups. The operation time and intraoperative blood loss of the two groups were recorded. Laboratory tests were performed at each time point before and after operation, including white blood cell (WBC), electrolytes (K, Ca, P, Mg), blood urea nitrogen (BUN), serum creatinine (Scr), glomerular filtration rate (eGFR), lymphocyte ratio (CD4/CD8), immunoglobulin G (IgG), IgM, alanine transaminase (ALT), aspartate aminotransferase (AST). After operation, Harris score was used to evaluate the hip joint function. CT of the hip joint and X-ray films in anteroposterior and frog positions of the pelvis were used to review the iliac bone flap position, fusion, and screw biodegradation in the trial group. Results The vital signs of the two groups were stable, the incisions healed by first intention, and no adverse events occurred after operation. One patient in the control group refused to return to the hospital for follow-up at 3 months after operation, and 1 patient in the trial group refused to return to the hospital for follow-up at 1 year after operation. The rest of the patients completed the follow-up at 2 weeks, 3 months, 6 months, and 1 year after operation. Laboratory tests showed that there was no significant difference in WBC, electrolytes (K, Ca, P, Mg), BUN, Scr, eGFR, CD4/CD8, IgG, IgM, ALT, and AST between the two groups at each time point before and after operation (P>0.05). The operation time and intraoperative blood loss of the trial group were significantly less than those of the control group (P<0.05). The Harris scores of the two groups at 1 year significantly increased when compared with the values before operation and at 6 months after operation (P<0.05). There was no significant difference in Harris score between the two groups at each time point (P>0.05). Postoperative CT of hip joint and X-ray films of pelvis showed that the iliac bone flap reached osseous fusion with the fenestration of the head and neck junction of femoral head in the two groups at 1 year after operation, and no loosening or shedding of iliac bone flap was observed during follow-up. In the trial group, there were signs of dissolution and absorption of the new biodegradable magnesium internal fixation screws after operation, and the diameter of the screws gradually decreased (P<0.05); no screw breakage or detachment occurred during follow-up. Conclusion In the treatment of ONFH with vascularized iliac bone flap grafting, the new biodegradable magnesium internal fixation screws can fix the iliac bone flap firmly. Compared with the traditional iliac bone flap wedging directly, it has a shorter operation time, less intraoperative blood loss, and can obtain similar joint function.
In recent years, 3D printing technology, as a new material processing technology, can precisely control the macroscopic and microstructure of biological scaffolds and has advantages that traditional manufacturing methods cannot match in the manufacture of complex bone repair scaffolds. Magnesium ion is one of the important trace elements of the human body. It participates in many physiological activities of the body and plays a very important role in maintaining the normal physiological function of the organism. In addition, magnesium ions also have the characteristics of promoting the secretion of osteogenic proteins by osteoblasts and osteogenic differentiation of mesenchymal stem cells. By combining with 3D printing technology, more and more personalized magnesium-based biological scaffolds have been produced and used in bone regeneration research in vivo and in vitro. Therefore, this article reviews the application and research progress of 3D printing magnesium-based biomaterials in the field of bone regeneration and repair.
Objective To review the research progress of magnesium and magnesium alloy implants in the repair and reconstruction of sports injury. Methods Relevant literature of magnesium and magnesium alloys for sports injury repair and reconstruction was extensively reviewed. The characteristics of magnesium and its alloys and their applications in the repair and reconstruction of sports injuries across various anatomical sites were thoroughly discussed and summarized. Results Magnesium and magnesium alloys have advantages in mechanical properties, biosafety, and promoting tendon-bone interface healing. Many preclinical studies on magnesium and magnesium alloy implants for repairing and reconstructing sports injuries have yielded promising results. However, successful clinical translation still requires addressing issues related to mechanical strength and degradation behavior, where alloying and surface treatments offer feasible solutions. Conclusion The clinical translation of magnesium and magnesium alloy implants for repairing and reconstructing sports injuries holds promise. Subsequent efforts should focus on optimizing the mechanical strength and degradation behavior of magnesium and magnesium alloy implants. Conducting larger-scale biocompatibility testing and developing novel magnesium-containing implants represent new directions for future research.
[Abstract]Esophageal stricture is a common esophageal lesion in adults and children, and endoscopic dilatation is currently the standard treatment. However, high recurrence rate and frequent dilations have become a major problem in patients. Esophageal stents provide sustained dilation therapy but can lead to serious complications such as displacement, perforation, and bleeding, necessitating removal. Biodegradable stents, with the advantage of both dilation and self-degradation, are promising potential solutions to this problem. Currently, biodegradable materials are mainly categorized into metals and polymers, leading to the development of magnesium alloy esophageal stents and polymer esophageal stents. Among polymer stents, PLLA stents and SX-ELLA stents have been put into clinical application. In recent years, with the advancement of 3D bioprinting technology, the personalized fabrication of biodegradable stents has become feasible. In this paper, we will outline the current research status and progress of biodegradable magnesium alloy stents and polymer stents, introduce the new process of constructing esophageal stents by 3D bioprinting technology, focus on the clinical research of SX-ELLA stents in pediatric and adult patients. We will also analyze the existing problems with biodegradable stents and the directions for future development.