Cardiovascular disease (CVD) remains one of the leading causes of mortality among adults globally, with continuously rising morbidity and mortality rates. Metabolic disorders are closely linked to various cardiovascular diseases and play a critical role in their pathogenesis and progression, involving multifaceted mechanisms such as altered substrate utilization, mitochondrial structural and functional dysfunction, and impaired ATP synthesis and transport. In recent years, the potential role of peroxisome proliferator-activated receptors (PPARs) in cardiovascular diseases has garnered significant attention, particularly peroxisome proliferator-activated receptor alpha (PPARα), which is recognized as a highly promising therapeutic target for CVD. PPARα regulates cardiovascular physiological and pathological processes through fatty acid metabolism. As a ligand-activated receptor within the nuclear hormone receptor family, PPARα is highly expressed in multiple organs, including skeletal muscle, liver, intestine, kidney, and heart, where it governs the metabolism of diverse substrates. Functioning as a key transcription factor in maintaining metabolic homeostasis and catalyzing or regulating biochemical reactions, PPARα exerts its cardioprotective effects through multiple pathways: modulating lipid metabolism, participating in cardiac energy metabolism, enhancing insulin sensitivity, suppressing inflammatory responses, improving vascular endothelial function, and inhibiting smooth muscle cell proliferation and migration. These mechanisms collectively reduce the risk of cardiovascular disease development. Thus, PPARα plays a pivotal role in various pathological processes via mechanisms such as lipid metabolism regulation, anti-inflammatory actions, and anti-apoptotic effects. PPARα is activated by binding to natural or synthetic lipophilic ligands, including endogenous fatty acids and their derivatives (e.g., linoleic acid, oleic acid, and arachidonic acid) as well as synthetic peroxisome proliferators. Upon ligand binding, PPARα activates the nuclear receptor retinoid X receptor (RXR), forming a PPARα-RXR heterodimer. This heterodimer, in conjunction with coactivators, undergoes further activation and subsequently binds to peroxisome proliferator response elements (PPREs), thereby regulating the transcription of target genes critical for lipid and glucose homeostasis. Key genes include fatty acid translocase (FAT/CD36), diacylglycerol acyltransferase (DGAT), carnitine palmitoyltransferase I (CPT1), and glucose transporter (GLUT), which are primarily involved in fatty acid uptake, storage, oxidation, and glucose utilization processes. Advancing research on PPARα as a therapeutic target for cardiovascular diseases has underscored its growing clinical significance. Currently, PPARα activators/agonists, such as fibrates (e.g., fenofibrate and bezafibrate) and thiazolidinediones, have been extensively studied in clinical trials for CVD prevention. Traditional PPARα agonists, including fenofibrate and bezafibrate, are widely used in clinical practice to treat hypertriglyceridemia and low high-density lipoprotein cholesterol (HDL-C) levels. These fibrates enhance fatty acid metabolism in the liver and skeletal muscle by activating PPARα, and their cardioprotective effects have been validated in numerous clinical studies. Recent research highlights that fibrates improve insulin resistance, regulate lipid metabolism, correct energy metabolism imbalances, and inhibit the proliferation and migration of vascular smooth muscle and endothelial cells, thereby ameliorating pathological remodeling of the cardiovascular system and reducing blood pressure. Given the substantial attention to PPARα-targeted interventions in both basic research and clinical applications, activating PPARα may serve as a key therapeutic strategy for managing cardiovascular conditions such as myocardial hypertrophy, atherosclerosis, ischemic cardiomyopathy, myocardial infarction, diabetic cardiomyopathy, and heart failure. This review comprehensively examines the regulatory roles of PPARα in cardiovascular diseases and evaluates its clinical application value, aiming to provide a theoretical foundation for further development and utilization of PPARα-related therapies in CVD treatment.

OBJECTIVE: To evaluate the immediate effect of Kuanxiong Aerosol (KXA) on perioperative coronary microcirculation in patients with unstable angina (UA) suffering from elective percutaneous coronary intervention (PCI). METHODS: From February 2021 to July 2023, UA inpatients who underwent PCI alone in the left anterior descending (LAD) branch were included. Random numbers were generated to divide patients into the trial group and the control group at a ratio of 1:1. The index of coronary microcirculation resistance (IMR) was measured before PCI, and the trial group was given two sprays of KXA, while the control group was not given. IMR was measured again after PCI, cardiac troponin I (cTnI) and creatine kinase isoenzyme-MB (CK-MB) were detected before and 24 h after surgery, and major cardiovascular adverse events (MACEs) were recorded for 30 days. The data statistics and analysis personnel were blinded. RESULTS: Totally 859 patients were screened, and 62 of them were involved into this study. Finally, 1 patient in the trial group failed to complete the post-PCI IMR and was excluded, 30 patients were included for data analysis, while 31 patients in the control group were enrolled in data analysis. There was no significant difference in baseline data (age, gender, risk factors, previous history, biochemical index, and drug therapy, etc.) between the two groups. In addition, differences in IMR, cTnI and CK-MB were not statistically significant between the two groups before surgery. After PCI, the IMR level of the trial group was significantly lower than that of the control group (19.56 ± 14.37 vs. 27.15 ± 15.03, P=0.048). Besides, the incidence of perioperative myocardial injury (PMI) was lower in the trial group, but the difference was not statistically significant (6.67% vs. 16.13%, P=0.425). No MACEs were reported in either group. CONCLUSIONS KXA has the potential of improving coronary microvascular dysfunction. This study provides reference for the application of KXA in UA patients undergoing elective PCI. (Registration No. ChiCTR2300069831).
Humans ; Percutaneous Coronary Intervention ; Male ; Microcirculation/drug effects* ; Female ; Angina, Unstable/physiopathology* ; Pilot Projects ; Middle Aged ; Aged ; Drugs, Chinese Herbal/pharmacology* ; Aerosols ; Troponin I/blood* ; Coronary Circulation/drug effects* ; Elective Surgical Procedures

Objective To evaluate the pharmacokinetic characteristics and safety of single and multiple oral azvudine tablets in healthy young and elderly Chinese subjects.Methods This was a open-label and parallel-group study.The trial consisted of two groups:healthy young subjects group and healthy elderly subjects group,with 12 subjects in each group.Enrolled subjects were first given a single dose,fasting oral azvudine tablet 5 mg,after a 3-day cleansing period entered the multiple dose phase,fasting oral azvudine tablet 5 mg·d-1 for 7 days.Results After a single dose of azvudine 5 mg,Cmax and AUC0-∞ were(4.76±2.12)ng·mL-1,(6.53±2.20)ng·mL-1·h,and Tmax,t1/2 were 0.75,1.87 h in young subjects;Cmax and AUC0-∞ were(6.40±3.25)ng·mL-1,(9.50±3.70)ng·mL-1·h,and Tmax,t1/2 were 0.63,2.66 h in elderly subjects.After a multiple dose of azvudine 5 mg·d-1 for 7 d,Cmax and AUC0-∞ were(3.26±1.61)ng·mL-1,(5.38±2.19)ng·mL-1·h,and Tmax,ss,t1/2,ss were 0.88,2.13 h in young subjects;Cmax,ss and AUC0-∞,ss were(3.97±2.09)ng·mL-1,(6.71±3.26)ng·mL-1·h,and Tmax,ss,t1/2,ss were 0.75,2.56 h in elderly subjects.Elderly/young geometric mean ratios and 90％CIs were 128.37％(88.23％-186.76％),139.93％(105.42％-185.72％),140.03％(106.33％-184.41％)for azvudine Cmax,AUC0-t,AUC0-∞ after a single dose,and were 118.66％(80.83％-174.20％),118.41％(83.60％-167.69％),118.95％(84.78％-166.89％)for azvudine Cmax,AUC0-t,AUC0_∞ after a multiple dose of azvudine 5 mg·d-1 for 7 d.Conclusion After single and multiple oral administration of azvudine tablets,systemic exposure to azvudine was higher in healthy elderly subjects compared with healthy young subjects.After taking azvudine tablets,the types,severity and incidence of adverse events and adverse drug reactions in healthy elderly people were not significantly different from those in healthy young subjects.Azvudine was found to be safe and well tolerated in healthy elderly subjects.

Objective To observe the effects and safety of semaglutide and saxagliptin combined with metformin in the treatment of type 2 diabetes mellitus(T2DM)with abdominal obesity(AO).Methods The data of patients with T2DM and AO were retrospectively analyzed.Patients with T2DM and AO were divided into semaglutide group and saxagliptin group according to the cohort method.Both groups were given metformin orally,0.5 g a time,tid.On this basis,the semaglutide group was injected with semaglutide,0.25 mg a time,2 weeks later,the dose was adjusted to 0.5 mg a time,qw.The saxagliptin group was given oral administration of saxagliptin on the basis of metformin,5 mg a time,qd.All patients received 3 months of treatment.Glucose metabolism indexes,pancreatic islet function indexes,adipokines and adverse drug reactions were compared between the groups.Results There were 48 cases in semaglutide group and 49 cases in saxagliptin group.After treatment,the levels of fasting plasma glucose(FPG)in the semaglutide group and the saxagliptin group were(7.45±1.22)and(7.98±1.30)mmol·L-1;the levels of 2 h plasma glucose(2 h PG)were(9.78±1.64)and(10.55±1.82)mmol·L-1;the levels of hemoglobin A1c(HbA1c)were(5.66±0.94)and(6.25±0.87)％;the levels of fasting insulin(FINS)were(29.12±2.46)and(34.34±7.15)pmol·L-1;the levels of fasting C-peptide(FC-P)were(292.66±67.53)and(319.03±77.92)pmol·L-1;homeostatic model assessment-insulin resistance(HOMA-IR)were 2.51±0.78 and 2.94±0.89;homeostatic model assessment-β(HOMA-β)were 51.74±15.31 and 43.72±14.56;levels of Irisin were(4.56±0.32)and(4.17±0.54)ng·L-1;the levels of spexin(SPX)were(0.71±0.15)and(0.64±0.17)ng·mL-1;the levels of asprosin(ASP)were(1.22±0.16)and(1.34±0.25)μg·L-1.The above indexes were significantly different between semaglutide group and saxagliptin group(all P＜0.05).The total incidence rates of adverse drug reactions in semaglutide group and saxagliptin group were 10.42％(5 cases/48 cases)and 2.04％(1 case/49 cases),without statistically significant difference(P＞0.05).Conclusion The combination of semaglutide and metformin can lower blood glucose and in patients with T2DM and AO more significantly,and improve pancreatic function and adipokines,with good safety.

ObjectiveCoronavirus is a class of long-standing pathogens, which are enveloped single-stranded positive-sense RNA viruses. The genome all encodes 4 structural proteins: spike protein (S), nucleocapsid protein (N), membrane protein (M), and envelope protein (E). The nucleocapsid protein (NP) serves as a key structural component of coronaviruses, playing a vital function in the viral life cycle. NP acts as an RNA-binding protein, with a critical role in identifying specific sequences within the viral genome RNA, facilitating the formation of ribonucleoprotein (RNP) complexes with viral RNA to stabilize the viral genome and contribute to viral particles assembly. The NP consists of two primary structural domains, the N-terminal domain (NTD) and the C-terminal domain (CTD). The NTD is primarily responsible for RNA binding, whereas the CTD is involved in polymerization. The N protein demonstrated to trigger the host immune response and to modulate the cell cycle of infected cells by interacting with host proteins. The NP, one of the most abundant protein in coronaviruses, is essential in understanding the pathogenic mechanism of coronaviruses through its interaction with host factors, which response for determining the virus pathogenicity. HCoV-229E is a widely distributed coronavirus that typically causes mild upper respiratory tract diseases, accounting for a significant portion of common cold cases. However, its pathogenicity is notably lower compared to other coronaviruses like MERS-CoV, SARS-CoV, and SARS-CoV-2. The exact molecular mechanism behind remains unexplained, and how HCoV-229E N protein influences virus replication, host antiviral immunity, and pathogenesis need to be further explored. MethodsProximity labeling-mass spectrometry technique and bioinformatics analysis were used to screen for potential host factors interacting with the NP of human coronavirus 229E (HCoV-229E). In this study, a recombinant adenovirus Ad-V5-NP^HCoV-229E-TurboID was constructed to express the fusion protein of HCoV-229E NP and biotin ligase (TurboID). A549 cells were infected with the Ad-V5-NP^HCoV-229E-TurboID. After 30 min biotin treatment, NP interacting proteins were labeled with biotin by biotin ligase, and subsequently isolated with streptavidin cross-linked magnetic beads. The potential interacting proteins were identified using label-free proteomic mass spectrometry and further validated through immunoprecipitation and immunofluorescence assays. ResultsWe identified a total of 584 potential interacting proteins. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted the enrichment of glycogen synthase kinase (GSK)3A and GSK3B in the glycolysis/gluconeogenesis pathway, indicating HCoV-229E NP connection to diabetes through aberrant activity. Moreover, SARS-CoV-2 infection can exacerbate hyperglycemia and metabolic dysregulation in diabetic individuals by activating the ACE2 receptor. Moreover, SARS-CoV-2 was observed to cause potentially harm to pancreatic β‑cells and leading to insulin deficiency, which not only worsens the condition of diabetic patients but also raises the possibility of new-onset diabetes in non-diabetic individuals. We demonstrated that GSK3A and GSK3B interacted with NP of HCoV-229E, suggesting that the NP may engage in various coronavirus pathogenic processes by interacting with GSK3. ConclusionThese findings suggest that proximity labeling-mass spectrometry technique is a valuable tool for identifying virus-host interaction factors, and lay the foundation for future investigations into the mechanisms underlying coronavirus replication, proliferation, and pathogenesis.

Objective To analyze the clinical characteristics of stiff left atrial syndrome (SLAS) after Mei mini maze procedure for atrial fibrillation (AF), and to explore its risk factors and treatments. Methods We retrospectively analyzed the clinical data of the patients who underwent Mei mini maze procedure in Xinhua Hospital between 2010 and 2020. According to whether SLAS occurred in the early postoperative period, patients were divided into a SLAS group and a non-SLAS group. The basic data, perioperative echocardiogram and laboratory test indexes of the two groups were compared. Results A total of 1 056 patients were collected. There were 672 (63.6%) males with an average age of 63.6±9.3 years, including 489 patients with persistent AF and 567 patients with paroxysmal AF. Fourteen (14/1 056, 1.3%) patients developed SLAS, with an average occurrence time of 2.1±1.1 days after the surgery. The average follow-up time of the whole group was 21.4±7.8 months. Two patients in the SLAS group developed SLAS again after discharge, and the occurrence time was 3 weeks and 4 weeks after the operation, respectively; while no SLAS occurred after discharge in the non-SLAS group. Diabetes and small preoperative left atrial diameter were risk factors for SLAS after surgery. Patients with SLAS had a good prognosis after adequate diuretic therapy. Conclusion The incidence of SLAS after Mei mini maze procedure for AF is low, and it mostly occurs in the early postoperative period. After adequate diuretic treatment, the prognosis is good.

Objective: To analyze the incidence and the related risk factors of retropharyngeal lymph node metastasis in patients with hypopharyngeal squamous cell carcinoma, evaluate the accuracy of preoperative enhanced CT in judging retropharyngeal lymph node metastasis, and investigate the impact of retropharyngeal lymph node metastasis on the prognosis. Methods: Retrospective analyses were made on 398 patients with hypopharyngeal squamous cell carcinoma who underwent surgery as the primary therapy and accepted retropharyngeal lymph node exploration and clearance during surgery in Shandong Provincial ENT Hospital from January 2014 to December 2019. Multivariate logistic regression analysis was used to clarify the related risk factors of retropharyngeal lymph node metastasis. Multivariate Cox regression analysis was used to investigate the impact of retropharyngeal lymph node metastasis on prognosis. The retropharyngeal lymph nodes of 218 cases with available preoperative enhanced CT images were evaluated by two experienced radiologists and compared with postoperative pathological results. Results: Retropharyngeal lymph node metastasis were confirmed in 54 of 398 (13.6%) cases according to postoperative pathology. The sensitivity and specificity of preoperative enhanced CT in the diagnosis of retropharyngeal lymph node metastasis were 34.6% and 91.1%, respectively, and the overall accuracy was 84.4%. Multivariate logistic regression analysis showed that the site of the primary lesion and pathological N stage were independent risk factors for retropharyngeal lymph node metastasis in hypopharyngeal squamous cell carcinoma. Patients with primary lesion located in the posterior wall of hypopharynx (OR=4.83, 95% CI: 1.27-18.40), N2 stage (OR=6.30, 95% CI: 2.25-17.67), and N3 stage (OR=26.89, 95% CI: 5.76-125.58) were prone to retropharyngeal lymph node metastasis. The 5-year overall survival rate of the 398 patients was 50.4%, and the 5-year disease-free survival rate was 48.3%. Multivariate Cox regression analysis showed that T stage, N stage, retropharyngeal lymph node metastasis, and radiotherapy were independent influencing factors for overall survival (T stage: HR=1.28, 95% CI: 1.06-1.54; N stage: HR=1.26, 95% CI: 1.14-1.40; retropharyngeal lymph node metastasis: HR=2.13, 95% CI: 1.47-3.08; radiotherapy: HR=0.54, 95% CI: 0.38-0.76) and disease-free survival of patients with hypopharyngeal squamous cell carcinoma (T stage: HR=1.26, 95% CI: 1.06-1.51; N stage: HR=1.25, 95% CI: 1.13-1.37; retropharyngeal lymph node metastasis: HR=2.24, 95% CI: 1.56-3.21; radiotherapy: HR=0.55, 95% CI: 0.40-0.77). Conclusions: Metastasis of retropharyngeal lymph nodes in hypopharyngeal squamous cell carcinoma is not rare. Enhanced CT is of low accuracy and limited value in diagnosing retropharyngeal lymph node metastasis. Primary lesions located in the posterior wall of the hypopharyngx, N2 stage, and N3 stage are independent high-risk factors for retropharyngeal lymph node metastasis. The prognosis of hypopharyngeal cancer patients with retropharyngeal lymph node metastasis is worse, and active surgical exploration and clearance can effectively reduce the mortality caused by retropharyngeal lymph node metastasis.
Humans ; Squamous Cell Carcinoma of Head and Neck/pathology* ; Lymphatic Metastasis/pathology* ; Retrospective Studies ; Carcinoma, Squamous Cell/surgery* ; Lymph Nodes/pathology* ; Hypopharyngeal Neoplasms/surgery* ; Prognosis ; Head and Neck Neoplasms/pathology* ; Neoplasm Staging

OBJECTIVE: To investigate the involvement of endothelial cells (ECs)-derived exosomes in the anti-apoptotic effect of Danhong Injection (DHI) and the mechanism of DHI-induced exosomal protection against postinfarction myocardial apoptosis. METHODS: A mouse permanent myocardial infarction (MI) model was established, followed by a 14-day daily treatment with DHI, DHI plus GW4869 (an exosomal inhibitor), or saline. Phosphate-buffered saline (PBS)-induced ECs-derived exosomes were isolated, analyzed by miRNA microarray and validated by droplet digital polymerase chain reaction (ddPCR). The exosomes induced by DHI (DHI-exo), PBS (PBS-exo), or DHI+GW4869 (GW-exo) were isolated and injected into the peri-infarct zone following MI. The protective effects of DHI and DHI-exo on MI hearts were measured by echocardiography, Masson's trichrome staining, and TUNEL apoptosis assay. The Western blotting and quantitative reverse transcription PCR (qRT-PCR) were used to evaluate the expression levels of miR-125b/p53-mediated pathway components, including miR-125b, p53, Bak, Bax, and caspase-3 activities. RESULTS: DHI significantly improved cardiac function and reduced infarct size in MI mice (P<0.01), which was abolished by the GW4869 intervention. DHI promoted the exosomal secretion in ECs (P<0.01). According to the results of exosomal miRNA microarray assay, 30 differentially expressed miRNAs in the DHI-exo were identified (28 up-regulated miRNAs and 2 down-regulated miRNAs). Among them, DHI significantly elevated miR-125b level in DHI-exo and DHI-treated ECs, a recognized apoptotic inhibitor impeding p53 signaling (P<0.05). Remarkably, treatment with DHI and DHI-exo attenuated apoptosis, elevated miR-125b expression level, inhibited capsase-3 activity, and down-regulated the expression levels of proapoptotic effectors (p53, Bak, and Bax) in post-MI hearts, whereas these effects were blocked by GW4869 (P<0.05 or P<0.01). CONCLUSION DHI and DHI-induced exosomes inhibited apoptosis, promoted the miR-125b expression level, and regulated the p53 apoptotic pathway in post-infarction myocardium.
Mice ; Animals ; Tumor Suppressor Protein p53/metabolism* ; Endothelial Cells/metabolism* ; Exosomes/metabolism* ; bcl-2-Associated X Protein/metabolism* ; Myocardium/metabolism* ; Myocardial Infarction/drug therapy* ; Apoptosis ; MicroRNAs/metabolism*

Objective:To analyze the clinical characteristics, treatment course and prognosis of children with intermediate-high risk pulmonary embolism.Methods:The clinical data of 48 children with pulmonary embolism treated in Beijing Children′s Hospital, Capital Medical University from January 2017 to December 2021 were analyzed retrospectively.Including 12 intermediate-high risk cases and 36 low-risk cases.The clinical manifestations, laboratory results, treatment and prognosis were compared between groups by the t-test, rank sum test and Chi- square test with the yates continuity correlation or Fisher′ s exact test. Results:There were no significant differences in the sex and age between the intermediate-high risk group and the low-risk group.The proportions of patients with shortness of breath, dyspnea, cyanosis or hypoxemia were higher in the intermediate-high risk group than those of in low-risk group.Twelve children in the low-risk group did not have specific symptoms of pulmonary embolism.There were no significant differences in the D-dimer level, and the distribution of pulmonary embolism between the two groups (all P>0.05). However, the proportion of children with other thromboembolism in the intermediate-high risk group was significantly higher than that of the low-risk group, among which heart thrombosis was the most common (7 cases). There were no significant differences in the underlying diseases and thrombophilia between the two groups (all P>0.05). The treatment of the intermediate-high risk group was more active: 6/12(50.00%) patients in the intermediate-high risk group received reperfusion treatment, including 3 cases of systemic thrombolysis, 1 case of catheter thrombolysis, and 2 cases of thrombectomy.In the low-risk group, only 1 case was treated with systematic thrombolysis.Unfavorable outcomes were reported in 3/48 (6.25%) patients, including 1 death of massive bleeding after catheter-directed thrombolysis in the acute phase, 1 case of recurrent pulmonary embolism after self-decided withdrawal and 1 case of progression of pulmonary embolism that was managed by surgical thrombectomy, all of whom were in the intermediate-high risk group. Conclusions:Shortness of breath, dyspnea, cyanosis or hypoxemia and co-existed venous thromboembolism were more common in intermediate-high risk cases.The treatment regimen of was more aggressive, but the incidence of unfavorable outcomes was higher in intermediate-high risk group; further research is needed to determine the risk factors for intermediate-high risk pulmonary embolism in children.

Objective:To explore the changes of left ventricular remodeling after artificial chordae implantation and its effect on the recurrence of mitral regurgitation(MR).Methods:Clinical data of 141 patients with severe mitral regurgitation(Carpentier type Ⅱ) repaired by artificial chordae technique in our hospital from January 2010 to December 2019 were retrospectively analyzed. Patients were divided into significant regurgitation group(15 cases) and non- significant regurgitation group(126 cases) according to the presence or absence of moderate regurgitation by follow-up echocardiography. To observe the effect of left ventricular reverse remodeling(LVRR) on the recurrence of MR after artificial chordae implantation and analyze the risk factors.Results:All patients successfully underwent mitral valvuloplasty with artificial chordae. In the early postoperative period(30 days after operation), LVRR appeared in both groups(LVEDD and LVESD were significantly smaller than those before operation, P<0.05); LVRR was further enhanced(LVEDD and LVESD were further reduced, P<0.05) in non- significant regurgitation group at 1 year after operation, but left ventricular remodeling reoccurred in significant regurgitation group at 1 year after operation(LVEDD and LVESD increased compared with the early postoperative period, P<0.05). After 12-132 months’ follow-up, 15 patients had more than moderate MR. In the early postoperative period, 13 patients had more than mild MR, 8 of which evolved to more than moderate MR during follow-up. Cox regression showed that LVEDD≥65 mm( HR=5.573) and more than mild MR in the early postoperative period( HR=8.801) were the risk factors for the recurrence of MR after artificial chordae implantation. Conclusion:LVRR appeared in the early postoperative period, and the degree of LVRR further increased at 1 year after operation, but the patients with significant MR would reappear left ventricular remodeling. Early postoperative LVRR had a bad effect on the recurrence of MR after artificial chordae implantation, while further enhanced LVRR at 1 year after operation had little effect on the recurrence MR.