This study aims to explore the effects and action mechanisms of the active ingredients in Buyang Huanwu Decoction(BYHWD), namely tetramethylpyrazine(TMP) and hydroxy-safflor yellow A(HSYA), on oxygen-glucose deprivation/reglucose-reoxygenation(OGD/R)-induced inflammation and oxidative stress of microglia(MG). Network pharmacology was used to screen the effective monomer ingredients of BYHWD and determine the safe concentration range for each component. Inflammation and oxidative stress models were established to further screen the best ingredient combination and optimal concentration ratio with the most effective anti-inflammatory and antioxidant effects. OGD/R BV2 cell models were constructed, and BV2 cells in the logarithmic growth phase were divided into a normal group, a model group, an HSYA group, a TMP group, and an HSYA + TMP group. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of inflammatory cytokines such as interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6). Oxidative stress markers, including superoxide dismutase(SOD), nitric oxide(NO), and malondialdehyde(MDA), were also measured. Western blot was used to analyze the protein expression of both inflammation-related pathway [Toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)] and oxidative stress-related pathway [nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)]. Immunofluorescence was used to assess the expression of proteins such as inducible nitric oxide synthase(iNOS) and arginase-1(Arg-1). The most effective ingredients for anti-inflammatory and antioxidant effects in BYHWD were TMP and HSYA. Compared to the normal group, the model group showed significantly increased levels of IL-1β, TNF-α, IL-6, NO, and MDA, along with significantly higher protein expression of NF-κB, TLR4, Nrf2, and HO-1 and significantly lower SOD levels. The differences between the two groups were statistically significant. Compared to the model group, both the HSYA group and the TMP group showed significantly reduced levels of IL-1β, TNF-α, IL-6, NO, and MDA, lower expression of NF-κB and TLR4 proteins, higher levels of SOD, and significantly increased protein expression of Nrf2 and HO-1. Additionally, the expression of the M1-type MG marker iNOS was significantly reduced, while the expression of the M2-type MG marker Arg-1 was significantly increased. The results of the HSYA group and the TMP group had statistically significant differences from those of the model group. Compared to the HSYA group and the TMP group, the HSYA + TMP group showed further significant reductions in IL-1β, TNF-α, IL-6, NO, and MDA levels, along with significant reductions in NF-κB and TLR4 protein expression, an increase in SOD levels, and elevated Nrf2 and HO-1 protein expression. Additionally, the expression of the M1-type MG marker iNOS was reduced, while the M2-type MG marker Arg-1 expression increased significantly in the HSYA + TMP group compared to the TMP or HSYA group. The differences in the results were statistically significant between the HSYA + TMP group and the TMP or HSYA group. The findings indicated that the combined use of HSYA and TMP, the active ingredients of BYHWD, can effectively inhibit OGD/R-induced inflammation and oxidative stress of MG, showing superior effects compared to the individual use of either component.
Oxidative Stress/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Animals ; Mice ; Glucose/metabolism* ; Cell Line ; Inflammation/genetics* ; Oxygen/metabolism* ; Pyrazines/pharmacology* ; Microglia/metabolism* ; NF-E2-Related Factor 2/immunology* ; NF-kappa B/immunology* ; Toll-Like Receptor 4/immunology* ; Anti-Inflammatory Agents/pharmacology* ; Humans

OBJECTIVE: High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory. Nogo-A is an important axonal growth inhibitory factor. However, its function in high-altitude hypoxia and its mechanism of action remain unclear. METHODS: In an in vivo study, a low-pressure oxygen chamber was used to simulate high-altitude hypoxia, and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway. Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats, and synaptic damage in the hippocampus and changes in oxidative stress levels were observed. In vitro, SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion (OGD/R) models. RESULTS: Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats, triggered oxidative stress in the hippocampal tissue, and reduced the dendritic spine density of hippocampal neurons. Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress, synaptic damage, and the learning and memory impairment induced by high-altitude exposure. CONCLUSION: Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure. GRAPHICAL ABSTRACT available in www.besjournal.com.
Animals ; Oxidative Stress ; Hippocampus/metabolism* ; Rats ; Nogo Proteins/genetics* ; Male ; Rats, Sprague-Dawley ; Hypoxia/metabolism* ; Altitude ; Synapses ; Humans ; Altitude Sickness/metabolism*

Objective To investigate the antibacterial effect and its preliminary mechanism of lavender essential oil on multi-drug resistant Acinetobacter baumannii.Methods Micro-dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)of lavender essential oil against multi-drug resistant Acinetobacter baumannii,and bactericidal kinetic study was employed to determine the onset and maintenance time of lavender essential oil.Meanwhile,the promoting and therapeutic effects of lavender essential oil on wound healing were observed in a mouse model of infection.Subsequently,crystal violet staining was used to determine the inhibition and clearance of multi-drug resistant Acinetobacter baumannii biofilm by lavender essential oil,and laser confocal microscopy was utilized to observe the survival of bacteria in biofilms.NanoDrop instrument was utilized to quantify the leakage of bacterial DNA nucleic acid and protein after intervention with 3 and 6 mg/mL lavender essential oil,and the leakage of bacterial potassium ion was measured by potassium ion test kit.Proteomics technology combined with bio-informatics were applied to explore the action mechanism of lavender essential oil against multi-drug resistant Acinetobacter baumannii.Results The MIC and MBC of lavender essential oil were both 6 mg/mL,which could kill almost all multi-drug resistant Acinetobacter baumannii at the time point of 120 min,and showed an obvious dose-and time-dependent manner.The overall animal model evaluation showed that both 3 and 6 mg/mL lavender essential oil could promote wound healing,and the curative effect was obvious.Further studies confirmed that 3 mg/mL lavender essential oil had a certain biofilm inhibitory effect on multi-drug resistant Acinetobacter baumannii,and 6 mg/mL also had a certain biofilm clearance effect under the same conditions.Meanwhile,when incubated at 37℃ for 1 h,the dose of 3 mg/mL could increase the leakage of DNA nucleic acid and protein,and significantly promote the efflux of potassium ions.Proteomic analysis suggested that the antibacterial effect of lavender essential oil may be related to affecting the oxidorereductase activity and cell metabolic process of multi-drug resistant Acinetobacter baumannii,and interfering with the biosynthesis of cell wall/membrane/envelope and other structures.Conclusion Lavender essential oil at 3 mg/mL can play an antibacterial effect against multi-drug resistant Acinetobacter baumannii,and its mechanism may be related to the destruction of bacterial biofilm and interference with bacterial metabolism.

Objective To explore the effect of long non-coding RNA(lncRNA)microRNA 17-92 cluster host gene(MIR17HG)regulating microRNA(miR)-214-3p/ring finger protein 38(RNF38)signal axis on the malignant biological behavior of liver cancer cells.Methods The cancer tissues and adjacent tissues of 46 patients with liver cancer who underwent surgical resection in our hospital from May 2022 to October 2023 were collected to detect the expression of lncRNA MIR17HG,miR-214-3p and RNF38.HepG2,Bel-7402,SMMC-7721 and HL-7702 cells were cultured in vitro,and the expression of lncRNA MIR17HG,miR-214-3p and RNF38 was compared,Bel-7402 cells were selected for further study,and randomly divided into sh-NC group,sh-MIR17HG group,anti-NC group,anti-miR-214-3p group and Bel-7402 group.The proliferation,apoptosis,invasion and migration of Bel-7402 cells in each group were investigated,the expression of RNF38,caspase-3(caspase-3),B cell lymphoma-2(Bcl-2),matrix metalloproteinase-2(MMP2)and matrix metalloproteinase-9(MMP9)protein was analyzed by western blotting,the relationship between lncRNA MIR17HG and miR-214-3p and the relationship between miR-214-3p and RNF38 were verified by double luciferase.Results The mRNA expression of lncRNA MIR17HG and RNF38 in liver cancer tissues was higher,the mRNA expression of miR-214-3p was lower,and the positive expression rate of RNF38 protein was higher(P＜0.05).The expression of lncRNA MIR17HG mRNA,RNF38 mRNA and RNF38 protein in SMMC-7721,HepG2 and Bel-7402 cells was higher than that in HL-7702 cells,and the expression of miR-214-3p mRNA was lower than that in HL-7702 cells(P＜0.05).Compared with Bel-7402 group and sh-NC group,the OD450nm value,the number of cloned cells,the number of invasive cells,the number of migrated cells and the expression of RNF38,MMP2,Bcl-2 and MMP9 in sh-MIR17HG group decreased,while the apoptosis rate and the expression of caspase-3 increased(P＜0.05).Compared with sh-MIR17HG group and anti-NC group,the OD450nm value,the number of cloned cells,the number of invasive cells,the number of migrated cells and the expression of RNF38,MMP2,Bcl-2 and MMP9 in anti-miR-214-3p group increased,while the apoptosis rate and the expression of caspase-3 decreased(P＜0.05).LncRNA MIR17HG and miR-214-3p,and miR-214-3p and RNF38 have targeted relationships respectively.The luciferase activity in miR-214-3p+WT-MIR17HG group was lower than that in miR-NC+WT-MIR17HG group(P＜0.05),and the luciferase activity in miR-214-3p+WT-RNF38 group was lower than that in miR-NC+WT-RNF38 group(P＜0.05).Conclusion LncRNA MIR17HG may promote the malignant biological behavior of liver cancer cells by regulating the miR-214-3p/RNF38 axis.

Objective To establish an acute exposure model of extreme plateau hypobaric hypoxia environment and explore transcriptomic changes related to learning and memory impairment in rats.Methods Healthy male SD rats aged 6-weeks,200-250 g,were selected and divided into control group and plateau group.The control group was treated with normal pressure and oxygen(19 rats),and the plateau group was placed in a hypobaric hypoxia chamber(19 rats)at a simulated altitude of 8000 meters and treated for 72 hours.Behavioral changes were detected with 16 animals from each group using contextual fear conditioning and Morris water maze(8 rats each).Three hippocampal tissues were extracted from each group for transcriptomic sequencing,and the molecular mechanism of learning and memory impairment induced by extreme plateau environment was analyzed by Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)and gene set enrichment analysis(GSEA)enrichment.Results The behavioral result showed that compared with the control group,the fear memory and spatial learning memory abilities of rats in plateau group were decreased.GO and KEGG analyses showed that the extreme altitude environment reshaped the hippocampal microenvironment and affected the intercellular signal transmission,while GSEA analysis showed that the extreme altitude environment up-regulated the gene set related to the plasma membrane and extracellular matrix.Conclusion The extreme plateau environment at an altitude of 8000 meters could affect the microenvironment of rat hippocampus,destroy intercellular connections and impair intercellular communication and then induce learning and memory impairment.

OBJECTIVE: To examine the anti-inflammatory effect of grape seed extract (GSE) in animal and cellular models and explore its mechanism of action. METHODS: This study determined the inhibitory effect of GSE on macrophage inflammation and Th1 and Th17 polarization in vitro. Based on the in vitro results, the effects and mechanisms of GSE on multiple sclerosis (MS)-experimental autoimmune encephalomyelitis (EAE) mice model were further explored. The C57BL/6 mice were intragastrically administered with 50 mg/kg of GSE once a day from the 3rd day to the 27th day after immunization. The activation of microglia, the polarization of Th1 and Th17 and the inflammatory factors such as tumor necrosis factor- α (TNF- α), interleukin-1 β (IL-1 β), IL-6, IL-12, IL-17 and interferon-γ (IFN-γ) secreted by them were detected in vitro and in vivo by flow cytometry, enzyme linked immunosorbent assay (ELISA), immunofluorescence staining and Western blot, respectively. RESULTS: GSE reduced the secretion of TNF-α, IL-1 β and IL-6 in bone marrow-derived macrophages stimulated by lipopolysaccharide (P<0.01), inhibited the secretion of TNF-α, IL-1 β, IL-6, IL-12, IL-17 and IFN-γ in spleen cells of EAE mice immunized for 9 days (P<0.05 or P<0.01), and reduced the differentiation of Th1 and Th17 mediated by CD3 and CD28 factors (P<0.01). GSE significantly improved the clinical symptoms of EAE mice, and inhibited spinal cord demyelination and inflammatory cell infiltration. Peripherally, GSE downregulated the expression of toll-like-receptor 4 (TLR4) and Rho-associated kinase (ROCKII, P<0.05 or P<0.01), and inhibited the secretion of inflammatory factors (P<0.01 or P<0.05). In the central nervous system, GSE inhibited the infiltration of CD45⁺CD11b⁺ and CD45⁺CD4⁺ cells, and weakened the differentiation of Th1 and Th17 (P<0.05). Moreover, it reduced the secretion of inflammatory factors (P<0.01), and prevented the activation of microglia (P<0.05). CONCLUSION GSE had a beneficial effect on the pathogenesis and progression of EAE by inhibiting inflammatory response as a potential drug and strategy for the treatment of MS.
Mice ; Animals ; Encephalomyelitis, Autoimmune, Experimental/pathology* ; Grape Seed Extract/therapeutic use* ; Interleukin-17 ; Interleukin-1beta ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Th1 Cells ; Mice, Inbred C57BL ; Interferon-gamma/therapeutic use* ; Th17 Cells/metabolism* ; Interleukin-12/therapeutic use* ; Cytokines/metabolism*

Objective To investigate the effect of plateau hypoxia on the blood-brain barrier after subarachnoid hemorrhage (SAH) in rats. Methods Adult male SD rats (n = 78) were randomly divided into 4 groups: sham group (sham), SAH model group (SAH), plateau hypoxia sham group (Hp sham) and plateau hypoxia SAH model group (Hp SAH). The rat model of plateau hypoxia was established through low-pressure simulation chamber (altitude 5000 m), and the SAH model was established by endovascular perforation method. At 24 hours after SAH, neurobehavior score and SAH grade were assessed. The morphological changes of neurons and apoptosis of nerve cells in the CA1 region of hippocampal were observed by the staining of Nissl and TUNEL. The expression of phosphorylated PI3K (p-PI3K), PI3K, phosphorylated Akt (p-Akt), Akt, phosphorylated nuclear factor κB (p-NF-κB), NF-κB, matrix metalloproteinase-9 (MMP-9), occludin and claudin-5 in hippocampal were detected by the method of Western blotting. The expression of occludin and claudin-5 proteins in the CA1 region of hippocampal were observed by immunofluorescent staining. Results At 24 hours after SAH, the neurobehavior score decreased significantly and SAH grade increased significantly in the SAH and Hp SAH group (P< 0.05). Neurobehavior score decreased significantly in the Hp SAH group compared with the SAH group (P < 0.05). In the SAH group, neurons in the CA1 region of hippocampus were atrophied and deformed, the arrangement were disordered, the number of neurons decreased significantly, and the apoptosis of nerve cells increased significantly(P< 0.05). Plateau hypoxia could aggravate the morphological damage of neurons and apoptosis of nerve cells. The expression of p-PI3K/PI3K, p-Akt/Akt, occludin and claudin-5 proteins decreased significantly, while the expression of p-NF-κB/NF-κB and MMP-9 proteins increased significantly in the SAH and Hp SAH group (P< 0.05). The expression of p-PI3K/PI3K and MMP-9 proteins increased significantly in Hp SAH group compared with the SAH group. The expression of claudin-5 protein increased significantly in Hp sham group compared with the sham group (P < 0.05). Immunofluorescent staining showed that the expression of occludin and claudin-5 proteins in the CA1 region of hippocampus decreased in the SAH group. Plateau hypoxia could further decreased the expression of occludin and claudin-5 proteins. Conclusion Plateau hypoxia aggravates blood-brain barrier disruption after subarachnoid hemorrhage in rats through inhibiting PI3K/Akt/NF-κB pathway.

Objective: To investigate the impact of combined use and timing of arterial-venous extracorporeal membrane oxygenation (VA-ECMO) with intra-aortic balloon pump (IABP) on the prognosis of patients with acute myocardial infarction complicated with cardiogenic shock (AMICS). Methods: This was a prospective cohort study, patients with acute myocardial infarction and cardiogenic shock who received VA-ECMO support from the Heart Center of Lanzhou University First Hospital from March 2019 to March 2022 in the registration database of the Chinese Society for Extracorporeal Life Support were enrolled. According to combination with IABP and time point, patients were divided into VA-ECMO alone group, VA-ECMO+IABP concurrent group and VA-ECMO+IABP non-concurrent group. Data from 3 groups of patients were collected, including the demographic characteristics, risk factors, ECG and echocardiographic examination results, critical illness characteristics, coronary intervention results, VA-ECMO related parameters and complications were compared among the three groups. The primary clinical endpoint was all-cause death, and the safety indicators of mechanical circulatory support included a decrease in hemoglobin greater than 50 g/L, gastrointestinal bleeding, bacteremia, lower extremity ischemia, lower extremity thrombosis, acute kidney injury, pulmonary edema and stroke. Kaplan-Meier survival curves were used to analyze the survival outcomes of patients within 30 days of follow-up. Using VA-ECMO+IABP concurrent group as reference, multivariate Cox regression model was used to evaluate the effect of the combination of VA-ECMO+IABP at different time points on the prognosis of AMICS patients within 30 days. Results: The study included 68 AMICS patients who were supported by VA-ECMO, average age was (59.8±10.8) years, there were 12 female patients (17.6%), 19 cases were in VA-ECMO alone group, 34 cases in VA-ECMO+IABP concurrent group and 15 cases in VA-ECMO+IABP non-concurrent group. The success rate of ECMO weaning in the VA-ECMO+IABP concurrent group was significantly higher than that in the VA-ECMO alone group and the VA-ECMO+IABP non-concurrent group (all P<0.05). Compared with the ECMO+IABP non-concurrent group, the other two groups had shorter ECMO support time, lower rates of acute kidney injury complications (all P<0.05), and lower rates of pulmonary edema complications in the ECMO alone group (P<0.05). In-hospital survival rate was significantly higher in the VA-ECMO+IABP concurrent group (28 patients (82.4%)) than in the VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (7 patients) (all P<0.05). The survival rate up to 30 days of follow-up was also significantly higher surviving patients within were in the ECMO+IABP concurrent group (26 cases) than in VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (4 patients) (all P<0.05). Multivariate Cox regression analysis showed that compared with the concurrent use of VA-ECMO+IABP, the use of VA-ECMO alone and non-concurrent use of VA-ECMO+IABP were associated with increased 30-day mortality in AMICS patients (HR=2.801, P=0.036; HR=2.985, P=0.033, respectively). Conclusions: When VA-ECMO is indicated for AMICS patients, combined use with IABP at the same time can improve the ECMO weaning rate, in-hospital survival and survival at 30 days post discharge, and which does not increase additional complications.
Humans ; Female ; Middle Aged ; Aged ; Shock, Cardiogenic/complications* ; Extracorporeal Membrane Oxygenation/methods* ; Pulmonary Edema/complications* ; Aftercare ; Prospective Studies ; Patient Discharge ; Myocardial Infarction/therapy* ; Intra-Aortic Balloon Pumping/methods* ; Treatment Outcome ; Retrospective Studies

Tumor has become the major reasons cause of death,and its vaccine has become the effective tracts of treatment and prevention by enhancing the immune response of patients.However,most vaccines which are recombination subunit protein antigens are poorly immunogenic and difficult to induce a robust immune response in patients with compromised immune systems,resulting in poor marketing approval.The core component of the vaccine adjuvant can greatly enhance the strength,speed and duration of the immune response,thus becoming the key to the development of an ideal tumor vaccine.Most tumor vaccines are combined with tradition adjuvant such as aluminum,MF59 and AS adjuvant,but their products and patents are monopolized by large foreign companies.We found that natural adjuvants have many unique advantages,such as good biocompatibility and biodegradability,promoting the maturation of dendritic cell and the secretion of immune cytokines,significantly enhancing the tumor vaccine immune response,etc.In this paper,the application and future development of natural polysaccharides,saponins,flavonoid and plant virus-like particles in cancer vaccines were reviewed,which may lay a solid foundation for the development of the original and innovative adjuvants with domestic independent intellectual property rights.

Objective: To investigate the impact of combined use and timing of arterial-venous extracorporeal membrane oxygenation (VA-ECMO) with intra-aortic balloon pump (IABP) on the prognosis of patients with acute myocardial infarction complicated with cardiogenic shock (AMICS). Methods: This was a prospective cohort study, patients with acute myocardial infarction and cardiogenic shock who received VA-ECMO support from the Heart Center of Lanzhou University First Hospital from March 2019 to March 2022 in the registration database of the Chinese Society for Extracorporeal Life Support were enrolled. According to combination with IABP and time point, patients were divided into VA-ECMO alone group, VA-ECMO+IABP concurrent group and VA-ECMO+IABP non-concurrent group. Data from 3 groups of patients were collected, including the demographic characteristics, risk factors, ECG and echocardiographic examination results, critical illness characteristics, coronary intervention results, VA-ECMO related parameters and complications were compared among the three groups. The primary clinical endpoint was all-cause death, and the safety indicators of mechanical circulatory support included a decrease in hemoglobin greater than 50 g/L, gastrointestinal bleeding, bacteremia, lower extremity ischemia, lower extremity thrombosis, acute kidney injury, pulmonary edema and stroke. Kaplan-Meier survival curves were used to analyze the survival outcomes of patients within 30 days of follow-up. Using VA-ECMO+IABP concurrent group as reference, multivariate Cox regression model was used to evaluate the effect of the combination of VA-ECMO+IABP at different time points on the prognosis of AMICS patients within 30 days. Results: The study included 68 AMICS patients who were supported by VA-ECMO, average age was (59.8±10.8) years, there were 12 female patients (17.6%), 19 cases were in VA-ECMO alone group, 34 cases in VA-ECMO+IABP concurrent group and 15 cases in VA-ECMO+IABP non-concurrent group. The success rate of ECMO weaning in the VA-ECMO+IABP concurrent group was significantly higher than that in the VA-ECMO alone group and the VA-ECMO+IABP non-concurrent group (all P<0.05). Compared with the ECMO+IABP non-concurrent group, the other two groups had shorter ECMO support time, lower rates of acute kidney injury complications (all P<0.05), and lower rates of pulmonary edema complications in the ECMO alone group (P<0.05). In-hospital survival rate was significantly higher in the VA-ECMO+IABP concurrent group (28 patients (82.4%)) than in the VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (7 patients) (all P<0.05). The survival rate up to 30 days of follow-up was also significantly higher surviving patients within were in the ECMO+IABP concurrent group (26 cases) than in VA-ECMO alone group (9 patients) and VA-ECMO+IABP non-concurrent group (4 patients) (all P<0.05). Multivariate Cox regression analysis showed that compared with the concurrent use of VA-ECMO+IABP, the use of VA-ECMO alone and non-concurrent use of VA-ECMO+IABP were associated with increased 30-day mortality in AMICS patients (HR=2.801, P=0.036; HR=2.985, P=0.033, respectively). Conclusions: When VA-ECMO is indicated for AMICS patients, combined use with IABP at the same time can improve the ECMO weaning rate, in-hospital survival and survival at 30 days post discharge, and which does not increase additional complications.
Humans ; Female ; Middle Aged ; Aged ; Shock, Cardiogenic/complications* ; Extracorporeal Membrane Oxygenation/methods* ; Pulmonary Edema/complications* ; Aftercare ; Prospective Studies ; Patient Discharge ; Myocardial Infarction/therapy* ; Intra-Aortic Balloon Pumping/methods* ; Treatment Outcome ; Retrospective Studies