Establishment and evaluation of a streptozotocin-induced diabetic encephalopathy rat model / 中国组织工程研究

BACKGROUND:Animal models of diabetic encephalopathy that have been studied mainly include streptozotocin-induced model,high-sugar and high-fat diet-induced model and spontaneous animal model.Establishing a simple,easy,short-cycle,safe and effective model of diabetic encephalopathy can help to explore the subsequent pathogenesis and screen therapeutic drugs. OBJECTIVE:To further explore and evaluate the method of building diabetic encephalopathy rat models. METHODS:Twenty Sprague-Dawley rats were randomly divided into control(n=10)and model(n=10)groups.Rats in the model group were given a single injection of 45 mg/kg streptozotocin in the left lower abdominal cavity,and those in the control group were given the same amount of citrate buffer.During the experiment,the body mass,feed intake,water intake and blood glucose were measured.After 8 weeks,the glucose tolerance and oxidative stress levels were measured,and the pathological changes of brain tissue and the expression of apoptotic proteins were compared between groups. RESULTS AND CONCLUSION:Compared with the control group,the food intake,water intake,encephalization quotient,blood glucose and area under the blood glucose curve were significantly increased in the model group,while the body mass decreased significantly(P<0.01).Histopathological examination of the brain showed that compared with the control group,the number of surviving nerve cells was significantly reduced in the model group(P<0.01),with more significant pathological damage of nerve cells.Compared with the control group,the activities of serum superoxide dismutase,catalase and glutathione in the model group were significantly decreased(P<0.01),and the content of oxidative malondialdehyde was significantly increased(P<0.05).The expression levels of apoptosis-related proteins Bax and Caspase-3 in brain tissue increased in the model group compared with the control group,while the expression of Bcl-2 decreased(P<0.01).In conclusion,an 8-week injection of 45 mg/kg streptozotocin can cause obvious pathological damage to the brain tissue of diabetic rats,to successfully establish the rat model of diabetic encephalopathy.

The mediating effect of loneliness between social support and mobile social media dependence / 中华行为医学与脑科学杂志

Objective:To explore the mediating effect of loneliness between social support and mobile social media dependence.Methods:From May to June 2021, a survey was conducted on 559 college students selected from a cluster by mobile social media dependence questionnaire, multidimensional scale of perceived social support and loneliness scale.SPSS 21.0 statistical software and PROCESS v3.5 program were used to test the mediating effect.Results:The total score of college students' dependence on mobile social media was (3.27±0.56), the saliency score was (3.51±0.60), the social gain score was (3.02±0.69), the compulsive score was (3.33±0.74), the conflicting score was (3.35±0.68), and the withdrawal score was (3.13±0.72). The mediating effect test found that loneliness played a complete mediating effect between social support and mobile social media dependence.The Bootstrap 95% CI interval corrected for the deviation of the indirect effect was -0.176--0.090, which did not contain 0 value.Similarly, loneliness also played a complete mediating role between social support and social gain, compulsive, conflict and withdrawal. Conclusion:Social support can affect mobile social media dependence through loneliness.It is suggested to reduce excessive loneliness as much as possible by cultivating students' ability to establish and maintain social support system, so as to use mobile social media rationally.

Hypocrellin A-based photodynamic action induces apoptosis in A549 cells through ROS-mediated mitochondrial signaling pathway

Over recent decades, many studies have reported that hypocrellin A (HA) can eliminate cancer cells with proper irradiation in several cancer cell lines. However, the precise molecular mechanism underlying its anticancer effect has not been fully defined. HA-mediated cytotoxicity and apoptosis in human lung adenocarcinoma A549 cells were evaluated after photodynamic therapy (PDT). A temporal quantitative proteomics approach by isobaric tag for relative and absolute quantitation (iTRAQ) 2D liquid chromatography with tandem mass spectrometric (LC-MS/MS) was introduced to help clarify molecular cytotoxic mechanisms and identify candidate targets of HA-induced apoptotic cell death. Specific caspase inhibitors were used to further elucidate the molecular pathway underlying apoptosis in PDT-treated A549 cells. Finally, down-stream apoptosis-related protein was evaluated. Apoptosis induced by HA was associated with cell shrinkage, externalization of cell membrane phosphatidylserine, DNA fragmentation, and mitochondrial disruption, which were preceded by increased intracellular reactive oxygen species (ROS) generations. Further studies showed that PDT treatment with 0.08 µmol/L HA resulted in mitochondrial disruption, pronounced release of cytochrome , and activation of caspase-3, -9, and -7. Together, HA may be a possible therapeutic agent directed toward mitochondria and a promising photodynamic anticancer candidate for further evaluation.

Effect of ovariectomy on the skin aging in rats with osteoporosis / 中国实验动物学报

Objective Ovariectomized rats are the most suitable model for the study of postmenopausal osteoporosis.However,the effect of ovariectomy on rat skin is little studied.The aim of this study was to observe the effect of ovariectomy on the skin aging indexes in rats.Methods 20 healthy 3-month-old female SD rats were randomly divided into sham group and ovariectomized (OVX) group.Serum estradiol was detected at 3 months after ovariectomy,the skin aging-related biochemical indexes such as catalase (CAT),glutathione peroxidase (GSH-Px),superoxide dismutase (SOD) activity and the content of malondialdehyde (MDA),hydroxyproline (HYP) and lipofuscin (LF) were also detected.The structure of skin tissue was observed and detected using a pathological image analysis system.Results The serum E2 of OVX rats was significantly lower than that in the sham group,the thickness of epidermis and dermis of OVX group was significantly thinner than that of the sham group (P<0.01),the amount of collagen fibers was decreased and their arrangement was very loose.Compared with the sham group,the activity of CAT,GSH-Px and SOD in the OVX group was significantly decreased (P<0.01),and the content of MDA was significantly increased (P<0.01).The content of HYP in skin tissue was significantly decreased,and LF content was significantly increased (P< 0.01) in the OVX group.Conclusions Skin aging can be induced at 3 months after ovariectomy in 3-month old rats,which may be a good model for the study of skin aging in postmenopausal women.

Influence of probucol combined atorvastatin on blood viscosity,TCD indexes and carotid plaque stabili-ty in patients with large artery-derived cerebral infarction / 心血管康复医学杂志

Objective:To explore influence of probucol combined atorvastatin on blood viscosity ,transcranial Doppler (TCD) indexes and carotid plaque stability in patients with large artery‐derived cerebral infarction .Methods :A total of 100 patients with large artery‐derived cerebral infarction treated in our hospital from Apr 2014 to Apr 2016 were selected .According to random number table ,patients were randomly and equally divided into atorvastatin group (received atorvastatin based on routine treatment ) and combined treatment group (received probucol based on atorv‐astatin group) ,both groups were treated for six months .Related indexes before and after treatment were compared between two groups .Results :Compared with atorvastatin group after treatment ,there were significant reductions in levels of TC ,TG and LDL‐C ,and significant rise in HDL‐C level (P<0.01 all);significant reductions in whole blood high shear viscosity [(6.23 ± 0.38) mPa/s vs .(4.20 ± 0.42) mPa/s] ,whole blood low shear viscosity [(21.17 ± 5.83) mPa/s vs .(18.10 ± 4.44) mPa/s] ,plasma viscosity [ (2.10 ± 0.45) mPa/s vs .(1.72 ± 0.34) mPa/s] and fibrinogen (Fg) level [(4.35 ± 1.36) g/L vs .(3.30 ± 1.38) g/L] ,P<0.01 all;significant rise in systolic blood flow velocity (Vs) [left :(87.43 ± 14.56) cm/s vs .(95.45 ± 18.37) cm/s]and mean blood flow velocity (Vm) [left :(60.89 ± 16.03) cm/s vs .(75.38 ± 19.36) cm/s]of left and right MCA ,significant reduction in pulsatility index(PI) [(0.85 ± 0.22) vs .(0.75 ± 0.12)] , P<0.05 or <0.01;significant reductions in unstable plaque score [(4.93 ± 0.40) scores vs .(4.12 ± 0.35) scores]and recurrence rate of cerebral infarction (16.00% vs .2.00% ) in combined treatment group ,respectiely P=0.001 ,0.014. Conclusion:Probucol combined atorvastatin can significantly reduce blood viscosity ,significantly improve hemodynamics in patients with large artery‐derived cerebral infarction .Its an‐ti‐atherosclerosis effect is obvious ,therefore it can be used to prevent or reduce recurrence of cerebral infarction .

Clinical significance of transcranial Doppler and end-tidal carbon dioxide partial pressure on cerebrovascular reserve capacity in cerebral vessels stenosis patients / 中国医师进修杂志

Objective To study the clinical significance of cerebrovascular reserve (CVR) capacity in cerebral vessels stenosis (CVS) patients with transcranial Doppler (TCD) and end-tidal carbon dioxide partial pressure (PETCO2).Methods Fifty-two CVS patients were divided into two groups:one blood vessel stenosis group (22 cases) and multi blood vessels stenosis group (30 cases).Forty-five normal persons were selected as control group.All the groups were routinely examined with TCD and PETCO2.Hypercapnia was induced by inhaling the carbon dioxide who breathed himself,and hypocapnia was induced by voluntary hyperventilation to investigate the CVR capacity.Results (1)The vasodilator reserve of affected side of one blood vessel stenosis group [(3.16 ± 2.73)％/mm Hg,1 mm Hg =0.133 kPa],the heavier side of multi blood vessels stenosis group [(2.41 ± 1.25)％/mm Hg],and control group [(3.75 ± 1.77)％/mm Hg] had significant difference (F =3.866,P ＜ 0.05).The vasodilator reserve of heavier side of multi blood vessels stenosis group was significantly lower than that of control group (t =-2.657,P ＜ 0.05).The overall reserve of affected side of one blood vessel stenosis group [(3.13 ± 1.38)％/mm Hg],the heavier side of multi blood vessels stenosis group [(2.01 ± 1.89)％/mm Hg],and control group [(3.51 ±0.92)％/mm Hg] had significant difference (F =5.905,P ＜ 0.05).The overall reserve of heavier side of multi blood vesse stenosis group was significantly lower than that of control group and affected side of one blood vessels stenosis group (t =-3.468,2.582,P ＜ 0.05).(2) There was no significant difference among the 3 groups in PETCO2 when eupnea,hypocapnia and hypercapnia.(3) The extent of vascular disease correlated negatively with the vasodilator reserve and overall reserve (r =-0.433 and-0.475,P＜0.05).Conclusions TCD and PETCO2 are simple,economic and effective methods for assessing CVR capacity.The CVR capacity is reduced in patients with cerebral vessels changes.