Purpose To investigate the application value of cardiac magnetic resonance tissue tracking imaging in assessing early heart failure(HF)in plateau environment.Materials and Methods Thirty male SD rats were randomly divided into 10 in the control group and 20 in the experimental group.The rats in the experimental group were transported to the Qinghai Plateau laboratory(average altitude 4 250 metre)for eight weeks of exposure,and then divided into the plateau hypoxia group and the plateau HF group,and the HF group was treated with 5 mg/ml Isoprenaline 10 mg/(kg·d)subcutaneously for 14 consecutive days to establish a HF rat model.The rats were then transported back to the plains(average elevation 500 metre)for 7T cardiac magnetic resonance movie sequence scanning.Cardiac function parameters and myocardial strain parameters were obtained using CVI 42 software.Myocardial pathological changes were detected using HE staining and Masson trichrome staining.Serum levels of malondialdehyde and glutathione peroxidase were detected by enzyme-linked immunosorbent assay.Western blot and PCR were used to detect the expression of nuclear factor-E2-related factor 2(NRF2)and heme oxygenase 1(HO-1)in myocardial tissues.Results Left ventricular ejection fraction was reduced in the HF group compared with the control group[(67.06±4.66)%vs.(61.91±2.11)%;F=4.149,P=0.037],and overall left ventricular circumferential strain was significantly reduced in the HF group compared with the control group[(-24.60±0.81)%vs.(-20.16±1.86)%;F=12.241,P=0.001],and pathologic staining showed necrosis as well as interstitial fibrosis in cardiomyocytes.Enzyme-linked immunosorbent assay results showed decreased glutathione peroxidase levels in the HF group[(1 079.94±70.58)U vs.(311.99±39.47)U;F=209.294,P=0.001]and increased malondialdehyde in the HF group compared with those in the control group[(7.24±2.48)μmol/L vs.(53.28±4.51)μmol/L;F=156.39,P=0.010).Western blot results showed significantly lower NRF2 and HO-1 expression in myocardial tissues of the HF group compared with those in the control group(1.00±0.00 vs.0.52±0.13;F=26.607,P=0.001).PCR results showed significantly lower NRF2 and HO-1 mRNA expression in myocardial tissues of the HF group compared with those in the control group(1.19±0.16 vs.0.31±0.07;F=84.784,P=0.010).Conclusion Magnetic resonance tissue tracking imaging can be used for early assessment of HF caused by plateau environment.

Purpose To explore the application value of magnetic resonance feature tracking to assess early heart failure in different rat models.Materials and Methods Fifty male SD rats were randomly divided into four groups:the control group(8 rats),the isoproterenol high dose(ISO-H)group(14 rats),the isoproterenol low dose(ISO-L)group(14 rats)and the coronary artery ligation surgery(myocardial infarction,MI)group(14 rats).The ISO-H group received intraperitoneal injections of ISO at 100 mg/kg once a week for two consecutive weeks.The ISO-L group received continuous intraperitoneal injections of ISO at 5 mg/(kg·d)for 14 days.The MI group underwent coronary ligation to establish a heart failure rat model.Scans using a 7T cardiac MRI cine sequence were performed after two weeks and four weeks.Heart function parameters and myocardial strain parameters were obtained using CVI 42 software.Serum markers of myocardial injury,including creatine kinase,creatine kinase-MB,lactate dehydrogenase and α-hydroxybutyric dehydrogenase levels,were measured.HE staining and Masson staining were used to detect myocardial pathological changes.Results Compared with the control group,the ISO-H group,ISO-L group and MI group showed significant changes in left ventricular ejection fraction(t=-2.387,P=0.04;t=5.622,P<0.001;t=17.715,P<0.001)and overall radial strain(t=-4.570,P=0.001;t=6.587,P<0.001;t=10.649,P<0.001)after two weeks.Compared with the control group,the ISO-H group,ISO-L group and MI group showed varying degrees of reduction in left ventricular ejection fraction(t=4.834,P=0.001;t=10.325,P<0.001;t=26.286,P<0.001)and overall radial strain(t=3.890,P=0.003;t=9.547,P<0.001;t=13.751,P<0.001)after four weeks.The serum markers of myocardial injury,including creatine kinase,creatine kinase-MB,lactate dehydrogenase and α-hydroxybutyric dehydrogenase levels,were significantly elevated(t=-93.373--11.019,P<0.001),and pathological staining revealed that all model groups exhibited varying degrees of myocardial cell hypertrophy,necrosis and interstitial fibrosis compared with the control group.Conclusion Magnetic resonance feature tracking has guiding significance for the dynamic monitoring,early diagnosis and prognosis assessment of heart failure in different rat models.

Purpose To investigate the application value of cardiac magnetic resonance tissue tracking imaging in assessing early heart failure(HF)in plateau environment.Materials and Methods Thirty male SD rats were randomly divided into 10 in the control group and 20 in the experimental group.The rats in the experimental group were transported to the Qinghai Plateau laboratory(average altitude 4 250 metre)for eight weeks of exposure,and then divided into the plateau hypoxia group and the plateau HF group,and the HF group was treated with 5 mg/ml Isoprenaline 10 mg/(kg·d)subcutaneously for 14 consecutive days to establish a HF rat model.The rats were then transported back to the plains(average elevation 500 metre)for 7T cardiac magnetic resonance movie sequence scanning.Cardiac function parameters and myocardial strain parameters were obtained using CVI 42 software.Myocardial pathological changes were detected using HE staining and Masson trichrome staining.Serum levels of malondialdehyde and glutathione peroxidase were detected by enzyme-linked immunosorbent assay.Western blot and PCR were used to detect the expression of nuclear factor-E2-related factor 2(NRF2)and heme oxygenase 1(HO-1)in myocardial tissues.Results Left ventricular ejection fraction was reduced in the HF group compared with the control group[(67.06±4.66)%vs.(61.91±2.11)%;F=4.149,P=0.037],and overall left ventricular circumferential strain was significantly reduced in the HF group compared with the control group[(-24.60±0.81)%vs.(-20.16±1.86)%;F=12.241,P=0.001],and pathologic staining showed necrosis as well as interstitial fibrosis in cardiomyocytes.Enzyme-linked immunosorbent assay results showed decreased glutathione peroxidase levels in the HF group[(1 079.94±70.58)U vs.(311.99±39.47)U;F=209.294,P=0.001]and increased malondialdehyde in the HF group compared with those in the control group[(7.24±2.48)μmol/L vs.(53.28±4.51)μmol/L;F=156.39,P=0.010).Western blot results showed significantly lower NRF2 and HO-1 expression in myocardial tissues of the HF group compared with those in the control group(1.00±0.00 vs.0.52±0.13;F=26.607,P=0.001).PCR results showed significantly lower NRF2 and HO-1 mRNA expression in myocardial tissues of the HF group compared with those in the control group(1.19±0.16 vs.0.31±0.07;F=84.784,P=0.010).Conclusion Magnetic resonance tissue tracking imaging can be used for early assessment of HF caused by plateau environment.

Purpose To explore the application value of magnetic resonance feature tracking to assess early heart failure in different rat models.Materials and Methods Fifty male SD rats were randomly divided into four groups:the control group(8 rats),the isoproterenol high dose(ISO-H)group(14 rats),the isoproterenol low dose(ISO-L)group(14 rats)and the coronary artery ligation surgery(myocardial infarction,MI)group(14 rats).The ISO-H group received intraperitoneal injections of ISO at 100 mg/kg once a week for two consecutive weeks.The ISO-L group received continuous intraperitoneal injections of ISO at 5 mg/(kg·d)for 14 days.The MI group underwent coronary ligation to establish a heart failure rat model.Scans using a 7T cardiac MRI cine sequence were performed after two weeks and four weeks.Heart function parameters and myocardial strain parameters were obtained using CVI 42 software.Serum markers of myocardial injury,including creatine kinase,creatine kinase-MB,lactate dehydrogenase and α-hydroxybutyric dehydrogenase levels,were measured.HE staining and Masson staining were used to detect myocardial pathological changes.Results Compared with the control group,the ISO-H group,ISO-L group and MI group showed significant changes in left ventricular ejection fraction(t=-2.387,P=0.04;t=5.622,P<0.001;t=17.715,P<0.001)and overall radial strain(t=-4.570,P=0.001;t=6.587,P<0.001;t=10.649,P<0.001)after two weeks.Compared with the control group,the ISO-H group,ISO-L group and MI group showed varying degrees of reduction in left ventricular ejection fraction(t=4.834,P=0.001;t=10.325,P<0.001;t=26.286,P<0.001)and overall radial strain(t=3.890,P=0.003;t=9.547,P<0.001;t=13.751,P<0.001)after four weeks.The serum markers of myocardial injury,including creatine kinase,creatine kinase-MB,lactate dehydrogenase and α-hydroxybutyric dehydrogenase levels,were significantly elevated(t=-93.373--11.019,P<0.001),and pathological staining revealed that all model groups exhibited varying degrees of myocardial cell hypertrophy,necrosis and interstitial fibrosis compared with the control group.Conclusion Magnetic resonance feature tracking has guiding significance for the dynamic monitoring,early diagnosis and prognosis assessment of heart failure in different rat models.

Objective To establish a hypobaric hypoxia rat model in a real high-altitude environment,to investigate the effects of the real high-altitude environment on rat bone mass and bone microstructure using multiple methods such as Micro CT,blood biochemistry,and pathology,and to explore the potential mechanisms involved.Methods Sprague Dawley(SD)rats were transported to the Yushu Plateau Laboratory(at 4250 m above sea level)in Qinghai Province and kept there for 4,or 8,or 18 months.These groups were designated as H-4,H-8,and H-18,respectively.Upon completion of the high-altitude exposure,these animals were transported to the Molecular Imaging Laboratory,West China Hospital,Sichuan University(at 500 m above sea level)in Chengdu for relevant testing and comparison with the control animals raised in a low-altitude environment for the same durations(designated L-4,L-8,and L-18).The tests performed included blood biochemistry,Micro CT imaging,and pathological assessments such as ELISA,Western blot,and HE and TRAP staining.Results Compared with that of the control group,the body mass of rats in the H-4 and H-18 groups decreased significantly(H-4 group vs.L-4 group:[513.75±35.10]g vs.[649.18±60.03]g,P＜0.01;H-18 group vs.L-18 group:[535.58±66.65]g vs.[670.86±44.96]g,P＜0.01).The serum Ca2+concentration was higher in the H-8 group and H-18 group compared to that in the control group(H-8 group vs.L-8 group:[2.48±0.09]mmol/L vs.[2.38±0.07]mmol/L,P＜0.05;H-18 group vs.L-18 group:[2.55±0.11]mmol/L vs.[2.13±0.27]mmol/L,P＜0.05).No statistically significant difference was observed in the concentration of P3+.Bone metabolism indicator cross-linked carboxy-terminal telopeptide of type Ⅰ collagen(CTX-Ⅰ)was significantly increased in all high-altitude groups compared to the low-altitude groups(H-4 group vs.L-4 group:[1.44±0.08]ng/mL vs.[0.70±0.13]ng/mL,P＜0.01;H-8 group vs.L-8 group:[1.52±0.10]ng/mL vs.[0.75±0.10]ng/mL,P＜0.01;H-18 group vs.L-18 group:[2.70±0.13]ng/mL vs.[1.94±0.15]ng/mL,P＜0.01).In addition,CT results showed a decrease in bone volume fraction of trabecular bone in the three high-altitude groups(H-4 group vs.L-4 group:[7.48±2.35]％vs.[10.40±2.93]％,P＜0.05;H-8 group vs.L-8 group:[7.17±2.68]％vs.[10.09±2.95]％,P＜0.05;H-18 group vs.L-18 group:[2.90±2.91]％vs.[8.68±4.11]％,P＜0.01),and increased trabecular separation in the three high-altitude groups(H-4 group vs.L-4 group:[0.70±0.12]mm vs.[0.60±0.06]mm,P＜0.05;H-8 group vs.L-8 group:[0.68±0.07]mm vs.[0.59±0.05]mm,P＜0.01;H-18 group vs.L-18 group:[0.80±0.09]mm vs.[0.70±0.09]mm,P＜0.05).TRAP staining showed an increase in osteoclasts in the H-4 and H-18 groups.Western blot results indicated an increase in the expression of receptor activator of nuclear factor-κB ligand(RANKL)and hypoxia inducible factor-1α(HIF-1α)in high-altitude environment,while the expression of osteoprotegerin(OPG)was inhibited.Conclusion The impact of high-altitude environment on rat femurs is characterized primarily by a reduction in trabecular bone mass and damage to bone microstructure.

Objective To explore the therapeutic effect of Cang-ai volatile oil(CAVO)on rats with myocardial hypertrophy(MH)exposed to the hypobaric hypoxic environment of the Qinghai-Tibet Plateau using 7.0-tesla(7.0T)cardiac magnetic resonance imaging(CMR).Methods A total of 50 male specific pathogen-free(SPF)Sprague-Dawley(SD)rats were randomly assigned to a low-altitude control(CON)group,hypobaric hypoxia(HH)group,myocardial hypertrophy modeling(MH)group,MH modeling plus CAVO treatment(MH+CAVO)group,and MH modeling plus benadryl hydrochloride treatment(MH+RX)group,with 10 rats in each group.Except for the CON group,the rats in all the groups were kept and fed in the standard way for 8 weeks in a high-altitude environment(at 4250 m above sea level),and then given the corresponding treatment drugs by gastric gavage.Afterwards,7.0T high field strength CMR was used to measure left ventricular(LV)function and myocardial strain.Hematoxylin-eosin(HE)staining and Masson staining were performed to observe myocardial interstitial fibrosis.Wheat germ agglutinin(WGA)staining was performed to analyze the cross-sectional area of cardiomyocytes.Transmission electron microscopy was used to observe the ultrastructural changes of the myocardium.Serum levels of cardiac troponin T(cTnT),superoxide dismutase(SOD),malondialdehyde(MDA),and glutathione peroxidase(GSH-PX)were measured by ELISA.Results Compared with those of the control group,the MH group had significantly lower left ventricular global circumferential strain(LVGCS)at(-18.85±1.67)％and left ventricular global longitudinal strain(LVGLS)at(-20.39±1.48)％(P＜0.05).However,the MH+CAVO group had significantly higher LVGCS at(-22.10±1.08)％and LVGLS at(-24.60±1.72)％compared with those of the MH group(both P＜0.05),indicating that CAVO treatment improved LV function.The MH group had a decreased level of serum glutathione peroxidase(GSH-Px)in comparison with the CON group([1173.49±27.10]U/mL vs.[300.83±47.25]U/mL,P＜0.01),a decreased SOD level in comparison with the CON group([302.27±3.65]U/mL vs.[105.96±4.03]U/mL,P＜0.01),and an increased level of serum malondialdehyde(MDA)in comparison with the CON group([57.91±1.13]μmol/L vs.[6.65±2.99]μmol/L,P＜0.01),suggesting that the antioxidant capacity of rats in the MH group was decreased.After CAVO intervention,rats in the MH+CAVO group exhibited an increase in the serum levels of SOD at(278.51±5.97)U/mL and GSH-Px at(961.82±17.56)U/mL,as well as a decrease in MDA at(17.79±1.33)μmol/L(all P＜0.05).Conclusion CAVO can effectively improve cardiac function in rats with cardiac hypertrophy exposed to high-altitude environment by modulating oxidative stress and ameliorating cardiac hypertrophy.

Purpose To explore the cardioprotective effect of cang-ai volatile oil(CAVO)on rats with cardiac function impairment model under low-pressure and low-oxygen environment in Tibet Plateau based on 7.0T cardiovascular magnetic resonance(CMR)imaging.Materials and Methods Forty SD rats were randomly divided into the normal group,the high altitude model group,the CAVO-treated group and the rhodiola rosea-treated group,with 10 rats in each group.Except for the normal group,the rats in other groups were transferred from the plain(500 m above sea level)to the Tibet Plateau(4 250 m above sea level)for two months,and then administered with the corresponding drugs by gavage for 14 d.The left ventricle function was measured by using a 7.0T high-field strength CMR and myocardial strain was analysed by using tissue tracing technique.HE staining was used to observe the morphology of cardiomyocytes,Masson staining to observe interstitial fibrosis,wheat germ agglutinin staining to observe cardiomyocyte hypertrophy,and transmission electron microscopy to observe the morphological changes of mitochondria in each group.Serum levels of creatine kinase,creatine kinase isoenzyme,lactate dehydrogenase,cardiac troponin T,superoxide dismutase,malondialdehyde and glutathione peroxidase were detected.Intracellular reactive oxygen species levels were detected using flow cytometry.Results The left ventricular ejection fraction of rats in the CAVO-treated group was higher than that of the high altitude model group[(66.61±1.38)％vs.(60.94±3.21)％;t=3.969,P=0.032];meanwhile,the global circumferential strain of the left ventricle in the CAVO-treated group was higher than that of the high altitude model group(-25.68±1.30 vs.-22.84±1.17;t=3.967,P=0.003).HE,Masson and wheat germ agglutinin staining showed hypertrophy and necrosis as well as interstitial fibrosis and ultrastructural disruption of cardiomyocytes in the high altitude model group,which improved after CAVO treatment.The level of cardiac troponin T in the serum of rats with CAVO treatment group was significantly decreased compared with that of the high altitude model group[(314.03±20.05)pg/ml vs.(518.30±18.13)pg/ml;1=13.090,P=0.001].Conclusion CAVO treatment can reduce cardiac injury caused by low-pressure hypoxia in high altitude,and its effect can be detected dynamically and non-invasively by 7.0T high-field strength CMR.

Objective:To analyze the clinical course and targeted therapy of pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome.Methods:The clinical history of a 6-year-old boy with PAPA syndrome, who was admitted to Hong Kong University Shenzhen Hospital in September 2017, was reviewed. His genetic diagnosis was confirmed by whole exome sequencing. The response to targeted therapy was evaluated by comparing the inflammatory markers (erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) and serum cytokines (interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α)) before and after biological agents treatment. For literature review, "PAPA syndrome" and"PSTPIP1 gene"were used as keywords to retrieve papers published from January 1997 to December 2019 from Pubmed, Wanfang and CNKI database.Results:The patient was a 6-year-old boy, admitted to the hospital due to recurrent joint swelling and pain for more than 4 years. Before treatment, the CRP (256 mg/L), ESR (105 mm/1 h) and cytokines including serum TNF-α (7.43 ng/L), IL-1 (<5 ng/L), IL-6 (301 ng/L) were significantly elevated. Culture of the joint effusion was negative, but the IL-6 level was above 1 000 ng/L. MRI showed osteomyelitis at the lower end of the right femur. Gene detection found a heterozygous variation of PSTPIP1 gene (c.748G>A, p.E250K). Arthralgia once alleviated after the initiation of tocilizumab and infliximab, but recurred after 1 year of treatment. Thereafter, the anti-IL-1 receptor antagonist (Anakinra) was commenced, followed by a significant improvement of the arthralgia, and a complete remission during the follow-up. Besides, the level of CRP, ESR, serum TNF-α, IL-1 and IL-6 were all decreased to normal on the last followed up in December 2019. Literature review found 29 articles and 87 patients in total. The initial symptoms included those of arthritis ( n=58), pyoderma gangrenosum ( n=33), and acne ( n=24). Among all the cases, 13 genotypes were confirmed, and 47 variations involved amino acid p.E250. Steroid and/or biological agents were used in most patients. Conclusions:PAPA syndrome should be suspected in children with recurrent pyogenic sterile arthritis, and an early diagnosis could be achieved by genetic test. Targeted treatment with biological agent may control the symptoms effectively. Biological agents can control symptoms of this disorder effectively.