Objective Toinvestigatetheexpressionofsuppressorofcytokinesignaling1(SOCS1)inoverloaded ventricle papillary muscle, so as to understand its expression characteristics in structural remodeling after the overloading and the biomechanical properties of the muscle under cubic jellyfish toxin-1(CfTX-1) pretreatment that can affect cell signal transduction. Methods Abdominal aortic-venous fistula (AVF) were operated in Kunming mice (n=5), and the cardiac left ventricles were harvested after two weeks of fistulation. The mice in normal group were sham operated as a control (n=5). In vitro culture, the left ventricular papillary muscle of normal mice was used (n=20). In the stretching group, the isolated papillary muscles were double-ratio stretched and fixed on silicone plate. In the relaxation group, the muscles were not stretched. A separated subgroup that transfected with SOCS1 plasmids were set in each group of stretching and relaxation. The papillary muscle samples of each group were cultured in culture medium for 3 days at 37 ℃, and then homogenized for extracting total protein. The total protein was separated by 10％ sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 23 ku band with SOCS1 was used as the target band, and the integrated optical density (IOD) value was measured by computer image analysis method. The expression of SOCS1 protein was detected by Western Blot and the imprinted IOD value was also measured. The papillary muscle in the stretching group was stretched by micro-positioned stretching method, and the initial load was 1 g. After stabilization, the papillary muscle was stretched by 15 mm for continuously 5 times, and the passive tension characteristic curves during the first and fifth stretching were observed and recorded. The peak passive tension (PTmax) and its deceleration velocity (DV) of the papillary muscle were calculated based on the curves. Results Comparing with the AVF group, the normal group had higher IOD values of 23 ku band and SOCS1 blot in total protein of the papillary muscle, and the differences were statistically significant (all P<0.01). The IOD value of 23 ku band in the SOCS1 transfected stretching group was significantly higher than those of the two relaxation groups, and the differences were statistically significant (all P<0.01). However, the difference of this value was not statistically significant between the two relaxation groups. The average IOD value of SOCS1 blot in the SOCS1 transfected stretching group was higher than those of the normal stretching group and the SOCS1 transfected relaxation group, and the differences were statistically significant (all P<0.01). Comparing with the normal group, the AVF group had higher PTmax and ultimate PTmax of the papillary muscles, and had a lower DV values, and the differences were statistically significant (all P<0.01). Conclusions The expression of SOCS1 is sensitive to tension load, and has a positive effect as an overload-sensitive signal in improving myocardial adaptability, protecting myocardial structure and maintaining systolic and diastolic function. CfTX-1 also has a positive effect on improving the compliance of ventricular papillary muscles.

Objective To investigate the endogenous carnosine,glutathione system and oxidative stress level in serum of patients with diabetic cardiomyopathy(DCM),and the potential relationships among them.Meth-ods The serum of 102 healthy people,96 patients with type 2 diabetes mellitus and 74 patients with diabetic car-diomyopathy in the third affiliated hospital of QiQihar Medical University were enrolled.Carnosine content was mea-sured by ELISA.T-GSH,GSH and GSSG were detected by using micro-enzyme labeling assay.GSH-Px,GST and GRAC were detected by using colorimetry. The content of NO was detected by nitrate reduction method. The con-tent of H2O2was detected by using molybdic acid coloring method. The activities of NOS and CAT was determined by colorimetry. Results Compared with the healthy control group,the average level of human serum carnosine, GSH content,GRAC,GSH/GSSG ratio,GST activity and T-SH content in the DM and DCM group were signifi-cantly reduced(P < 0.05,respectively). NO content,H2O2and iNOS activity were increased,but CAT activity was decreased in DCM group.Conclusion Decreases of levels of serum carnosine and glutathione(GSH)and the imbalance of redox state were observed in patients with diabetic cardiomyopathy,which may promote the occur-rence and development of the diabetic cardiomyopathy.

Objective To investigate the differences in mechanical properties of the sclera in different regions. Methods The sclera of sus scrofa was divided into 3 regions, namely, anterior, equatorial and posterior area. Local indentation was performed on different areas of the whole sclera. Strip specimens of different regions were circumcised along the equatorial direction, and subjected to uniaxial stretching by INSTRON 5544. Results Within the normal physiological stress range, the stiffness at anterior, equatorial, and posterior area of the sclera measured by local indentation was (0.91±0.21), (0.6±0.16), (0.39±0.13) MPa, respectively. The elastic modulus at anterior, equatorial, and posterior area of the sclera measured by uniaxial stretching was (1-28±0.37), (0.95±0.31), (0.72±0.28) MPa, respectively. Conclusions The local indentation could reflect regional mechanical properties of the sclera. The anterior sclera performed a higher stiffness than the equatorial and posterior areas. The results provide references for further study on the pathogenesis of ocular diseases including myopia.

The mechanical properties of the aorta tissue is not only important for maintaining the cardiovascular health, but also is closely related to the development of cardiovascular diseases. There are obvious differences between the ventral and dorsal tissues of the descending aorta. However, the cause of the difference is still unclear. In this study, a biaxial tensile approach was used to determine the parameters of porcine descending aorta by analyzing the stress-strain curves. The strain energy functions Gasser-Ogden-Holzapfel was adopted to characterize the orthotropic parameters of mechanical properties. Elastic Van Gieson (EVG) and Sirius red stain were used to observe the microarchitecture of elastic and collagen fibers, respectively. Our results showed that the tissue of descending aorta had more orthotropic and higher elastic modulus in the dorsal region compared to the ventral region in the circumferential direction. No significant difference was found in hyperelastic constitutive parameters between the dorsal and ventral regions, but the angle of collagen fiber was smaller than 0.785 rad (45°) in both dorsal and ventral regions. The arrangement of fiber was inclined to be circumferential. EVG and Sirius red stain showed that in outer-middle membrane of the descending aorta, the density of elastic fibrous layer of the ventral region was higher than that of the dorsal region; the amount of collagen fibers in dorsal region was more than that of the ventral region. The results suggested that the difference of mechanical properties between the dorsal and ventral tissues in the descending aorta was related to the microstructure of the outer membrane of the aorta. In the relatively small strain range, the difference in mechanical properties between the ventral and dorsal tissues of the descending aorta can be ignored; when the strain is higher, it needs to be treated differently. The results of this study provide data for the etiology of arterial disease (such as arterial dissection) and the design of artificial blood vessel.
Animals ; Aorta, Thoracic ; physiology ; Biomechanical Phenomena ; Collagen ; Elastic Modulus ; Stress, Mechanical ; Swine

The effect of parasitic ions on the results of ultraviolet A (UVA) cross-linking in iontophoresis was still not clear. In this work, the porcine sclera was cross-linked by riboflavin lactate Ringer's solution (group A) and riboflavin normal saline (group B)
Animals ; Collagen ; Cross-Linking Reagents ; Ions ; Iontophoresis ; Permeability ; Photosensitizing Agents/pharmacology* ; Riboflavin ; Sclera ; Swine ; Ultraviolet Rays

Dental hard tissues lack the ability to self-heal. In dentin and cementum, hydroxyapatite (HA) can exist outside and/or inside collagen fibers. It is difficult to repair or regenerate HA with a highly ordered orientation in the presence of collagen fibers. At present, the biomimetic mineralization of dentin and cementum, mainly carried out by imitating its biological formation process and its physiological structure, can be divided into those originating from the fiber mineralization mechanism and those with HA as the main component. The materials used include natural materials such as demineralized dentin matrix (DDM) and calcined bovine hydroxyapatite (BHA), and synthetic materials such as polymer-induced liquid precursor (PILP) and synthetic HA. In the future, natural materials and synthetic materials should be combined for the restoration and regeneration of dentin and cementum by means of biomimetic mineralization of calcium phosphate released by remineralization solution-HA.