Objective: To observe the relationship between impaired myocardial untwisting and left ventricular diastolic dysfunction in patients with autoimmune diseases (AD). Methods: In this retrospective study, 95 AD patients (27 males, (38.6±14.2) years old) were enrolled as AD group and 71 gender and age matched healthy subjects (24 males, (37.6±12.2) years old) were enrolled as control group, all underwent transthoracic echocardiography and two-dimensional speckle-tracking echocardiography (STE) in our hospital between January 2014 and June 2018. Left ventricular untwisting and diastolic function parameters were measured. Multiple logistic regression analysis was used to identify related factors of left ventricular diastolic dysfunction in AD patients. Receiver operating characteristic (ROC) curve was used to identify the diagnosis value of untwisting parameters for left ventricular diastolic dysfunction in AD patients. Results: Compared with control group, left ventricular ejection fraction was lower (58(47, 66)% vs. 67 (62, 71) %, P<0.001), E/e′ was higher (10.78 (7.28, 13.65) vs. 6.30 (5.55, 7.25) , P<0.001), isovolumic relaxation time was longer (73.5 (56.5, 88.0) ms vs. 62.0 (58.0, 68.5) ms, P<0.001),and untwist slope during isovolumic relaxation period (USIR) was lower (31.92 (14.09, 54.92) °/s vs. 59.90 (40.09, 87.18) °/s, P<0.001) in AD group than in control group. Multiple logistic regression analysis showed heart rate (OR=0.885, 95%CI 0.840-0.931, P<0.001), E/e′ (OR=0.655, 95%CI 0.537-0.798, P<0.001) and USIR (OR=0.986, 95%CI 0.974-0.998, P=0.020) were independently related with left ventricular diastolic dysfunction in AD patients. ROC curve showed that area under the curve (AUC) was 0.919 (P<0.001), sensitivity was 87.6%, and specificity was 88.7%, when combining the heart rate, E/e′, and USIR as assessment parameters for the diagnosis of left ventricular diastolic dysfunction in AD patients at a cutoff of 0.51. Conclusions Impairment of myocardial untwisting indicates the presence of early stage left ventricular diastolic dysfunction in AD patients. USIR may be a sensitive parameter to evaluate early stage left ventricular diastolic dysfunction in AD patients.

Objective:To prepare hydroxyapatite(HA)coating on polyether ether ketone(PEEK)surface by magnetron sputtering technique and to study its biosafety.Methods:Sulfonated PEEK was used to increase the binding area and HA coating was constructed on it using magnetron sputtering technology.SEM and energy dispersive spectroscopy(EDAX)were used to detect the construction effect.Cell adhesion assay,cytoskeletal fluorescence staining and SEM validation were used to assess cytologrcal safety.In vivo safety tests were conducted in SD rats and golden hamsters.Results:HA coating with gradient morphology was successfully constructed on the PEEK surface using above technique.The coating promoted cell adhesion,extension and proliferation.No systemic toxicity and no sig-nificant influence in HE staining of the main infernal organs samples were observed.The coating alleviated the oral mucosal irritation caused by simple sulfonation to a certain extent.Conclusion:HA coating can be prepared stably with magnetron sputtering technology and can meet the biosafety needs for clinical applications.