Objective To investigate the effect of Alzheimer' s beta-amyloid (Aβ) on the production and the translocation in cytoplasm of retinoid receptor-α (RXRα). MethodsN2awt cells were treated with Aβ peptide or amyloid protein precursor(APP695) transfection. The nucleus were separated from the cytoplasm by kit. The quantity of RXRα in the nucleus and cytoplasm was detected by Westernblot. The translocation of RXRα in the nucleus and cytoplasm of above N2awt cells or of the cortex cells in the brains of Alzheimer' s disease (AD) patients and their normal control groups was observed by immune fluorescence. ResultsIn N2awt cells, the increasing APP or Aβ had no significant effect on the production of RXRα but resulted in RXRα exporting into cytoplasm, the ratio of RXRα in cytoplasm increased from 3.2％ (in control group) to 17.6％ (in APP+ group) and from 3.8％ (in control group) to 14.3％ (in Aβ + group) respectively; compared with normal cortex cells, the translocation of RXRα in the cytoplasm of the cortex cells in the brains of AD increased significantly. ConclusionAβ may affect RXRα exporting into cytoplasm.

Objective To analyze the effects of an inhibitor of the SH3 (Src homology) domains of Grb2 on the growth and proliferation of K562 cells. Methods The peptidimer [(VPPPVPPRRR)2-K], penetratin (RQIKIWFQNRRMKWKK) and peptidimer-c [poptidimer linked to penetratin: (VPPPVPPRRR)2-K-Aha-RQIKIWFQNRRMKWKK] were synthesized by solid-phase synthesis using Fmoc chemistry, and purified by high performance liquid chromatography (HPLC) on a C18 column. Purity was evaluated by HPLC, and the identity of the peptides was checked by electrospray mass spectroscopy (MS). A pull-down assay was used to observe the specific binding of peptidimer-c to the Grb2 of K562 cell lysates. The inhibition of peptidimer-c on K562 cell proliferation was evaluated by trypan blue exclusion assay, the cytostatic effect was tested by clonogenic assay, and the cytotoxicity was examined by WST-1 method. A further experiment was performed with clonogenic assay to analyze the co-effect of peptidimer-c respectively combined with Gleevec, Hydroxyurea and Cytarabine by Jing's method. Results The HPLC analysis showed only a simple peak, which means that the peptide is in high purity. MS analysis showed the peptides were coincided with the design. The molecular weight of peptidimer-c was of 4794.0 and that of the penetratin 2246.7. Pull-down assay demonstrated that the peptidimer-c, not the penetratin, could bind to Grb2 specifically. The trypan blue assay showed that the peptidimer-c could inhibit the proliferation of K562 significantly in a dose-dependent manner, even 3～6 h after the cells were exposed to the drug, and penetratin alone did not influence the cell proliferation. Gleevec inhibited the growth of K562 not only in a dose-dependent manner, but also in a time-dependent manner. WST-1 test showed the cytotoxieity of peptidimer-c or Gleevec on K562 cells, the IC50 of peptidimer-c was (17±2) μmol/L and the IC50 of Gleevec was (0.25±0.05) μmol/L. In the methylcellulose semi-solid medium system, the colony formation of K562 was greatly decreased by peptidimer-c as compared to the penetratin, and the colony number decreased as the dose of peptidimer-c increased. The IC50 value ofpeptidimer-c on K562 colony formation was (3.9±0.9) μmol/L, IC50 of Gleevec was (0.03±0.02) μmol/L, IC50 of Hydroxyurea was (15±7) μmol/L, and that of cytarabine was (0.014±0.012) μmol/L. There were synergistic effects of peptidimer-c with Gleevec, Hydroxyurea or Cytarabine on K562 by colonogenic assay. Combination of 1.5 μmol/L peptidimer-c and 0.05 μmol/L Gleevec showed synergistic effect on K562, as well as the combination of 1.5 μmol/L peptidimer-c and 0.006 μmol/L or 0.01 μmol/L Cytarabine. Conclusion These results suggested that peptidimer-c had an inhibitory effect on K562 cells and combination of peptidimer-c with other drugs would increase the anti-cancer effects.

Objective To compared different fixation methods for acetabular fractures involving the quadrilateral plate using a finite element model of the acetabulum.Methods A model of acetabular fractures with quadrilateral plate involved was developed in the finite element software and processed in Hypermesh V10.0 to generate internal fixation with dual-column titanium plate (Group A),anterior special titanium moulding plate plus quadrilateral screws (Group B),and anterior special titanium moulding plate plus quadrilateral screws combined with posterior column screws (Group C).Pelvic stress in sitting and standing positions were simulated in sequence with constraint of tuber nodes and inferior femur.Maximum stress and displacement of the acetabulum and displacement of nodes on fracture lines were measured after a force of 600 N was applied to S1 verterbrae in line with the direction of gravity in sitting and standing positions.Results In sitting position,the maximum stress and displacement of the acetabulum exhibited a sequence of Group C (9.47,1.08) ＜ Group B (19.84,1.11) ＜ Group A (29.73,1.14).Moreover,the same result was found in standing position with Group C (9.62,1.09) ＜ Group B (12.18,1.10) ＜ Group A (13.28,1.13).Mean displacement of nodes on fracture lines ranked in order of Group C ＜ Group B ＜ Group A (P ＞ 0.05).Conclusions The finite element model can reflect the distribution of pelvic stress effectively.Anterior special titanium moulding plate plus quadrilateral screws combined with posterior column screws provide favorable biomechanical stability in treatment of acetabular fractures involving the quadrilateral area.

We developed a three-dimensional finite element model of the pelvis. According to Letournel methods, we established a pelvis model of T-shaped fracture with its three different fixation systems, i. e. double column reconstruction plates, anterior column plate combined with posterior column screws and anterior column plate combined with quadrilateral area screws. It was found that the pelvic model was effective and could be used to simulate the mechanical behavior of the pelvis. Three fixation systems had great therapeutic effect on the T-shaped fracture. All fixation systems could increase the stiffness of the model, decrease the stress concentration level and decrease the displacement difference along the fracture line. The quadrilateral area screws, which were drilled into cortical bone, could generate beneficial effect on the T-type fracture. Therefore, the third fixation system mentioned above (i. e. the anterior column plate combined with quadrilateral area screws) has the best biomechanical stability to the T-type fracture.
Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Finite Element Analysis ; Fracture Fixation, Internal ; Fractures, Bone ; pathology ; Humans ; Models, Anatomic ; Pelvis ; anatomy & histology ; injuries ; Posture

Objective To analysis the clinical effects of treatment of femoral nerve injury using microsurgical technique. Methods Twenty-six cases of patients of femoral nerve injury was treated by nerve suture, nerve grafts and neurolysis separtately. Functional rehabilitation exercise was done actively postoperation. Results Follow-up 1～4 years, the average excellent rate was 84.6%. Conclusion Early diagnosis and accurately location, in timely microsurgical repair and actively functional rehabilitation exercise can ensure the satisfactory effects.

OBJECTIVE To investigate the correlated resistant genes encoding ?-lactamases,aminoglycoside and genetic marker of integron and transposon in multi-resistant Pseudomonas aeruginosa(MRPA) isolated from clinical specimens and study their relationship by phylogenetic analysis.METHODS Twenty-one resistant genes,two integron-Ⅰ genes and one transposon genetic gene were analyzed by PCR and verified by DNA sequencing.Multi-resistant genes cluster analysis was performed by UPGMA.RESULTS The positive rates of CARB,oprD2,aac(3)-Ⅱ,aac(6′)-Ⅱ,ant(2″)-Ⅰ,intⅠ1,qacE△1-sul1 and merA in 20 strains of MRPA were 15%,100%,70%,15%,15%,85%,85% and 85%,respectively,and other genes were negative.It was classfied to three subgroup,by the multi-resistant genes cluster analysis.CONCLUSIONS MRPA isolated from clinical specimens has carried many resistant genes.The deficiency rate of oprD2 gene is very high.The positive rate of genetic mark genes about integron and transposon is very high.It may be the main multi-resistant mechanism of MRPA.Multi-resistant genes cluster analysis shows that there is clone transmission in MRPA and it can induce nosocomial infection prevalence.

To investigate the influence of bear bile on rat hepatocarcinoma induced by diethylnitrosamine (DEN), a total of 40 rats were randomly divided into 4 groups: normal control group, model group, and two bear bile treatment groups. The rat liver cancer model was induced by breeding with water containing 100 mg x L(-1) DEN for 14 weeks. The rats of the bear bile groups received bear bile powder (200 or 400 mg x kg(-1)) orally 5 times per week for 18 weeks. The general condition and the body weight of rats were examined every day. After 18 weeks the activities of serum alanine transaminase (ALT), aspartate transaminase (AST) and total bilirubin (TBIL) were detected. Meanwhile, the pathological changes of liver tissues were observed after H&E staining. The expression of proliferative cell nuclear antigen (PCNA) and a-smooth muscle actin (alpha-SMA) in liver tissue were detected by immunohistochemical method. After 4 weeks the body weights of rats in normal group were significantly more than that in other groups (P < 0.05); and that in the two bile groups was significantly more than that in the model group. Compared with normal group, the level of serum glutamic-pyruvic transaminase and total bilirubin increased significantly in other groups; compared with model group, these two indexes decreased significantly in two bile groups. Hepatocellular carcinoma occurred in all rats except for normal group; there were classic cirrhosis and cancer in model group while there were mild cirrhosis and high differentiation in two bile groups. There were almost no expressions of PCNA and alpha-SMA in normal group while there were high expressions in model group; the two bile groups had some expressions but were inferior to the model group, and alpha-SMA reduced markedly. It indicated that bear bile restrained the development of liver cancer during DEN inducing rat hepatocarcinoma, which may be related to its depressing hepatic stellate cell activation and relieving hepatic lesion and cirrhosis.

BACKGROUND: Induced pluripotent stem cells are a type of reprogrammed cells with similar characteristics to embryonic stem cells, which are capable of differentiating into phenotypes associated with patient specific diseases. Moreover, their clinical application avoids ethical issues. OBJECTIVE: To review the research progress of induced pluripotent stem cells in myocardial regeneration and repair, cardiovascular disease models, drug development and screening, and drug toxicity testing. METHODS: PubMed (2006-2018) and CNKI (2013-2018) databases were retrieved for relevant articles using the keywords of "induction of pluripotent stem cells; myocardial infarction; arrhythmia; cardiovascular disease; heart failure; heart transplantation; disease model; drug toxicity" in English and Chinese, respectively. The data were reviewed one by one, and the citations involved in the literatures were also reviewed. RESULTS AND CONCLUSION: Induced pluripotent stem cells have great potential value in myocardial regeneration and repair, establishment of cardiovascular disease models, new drug development and screening, and drug toxicity detection. The application prospect of the cells is broad, but most of the research is still in the experimental stage. In addition, safety problems, such as low induction efficiency and tumorigenicity, will limit the clinical application of induced pluripotent stem cells.

Peptide dual agonists toward both glucagon-like peptide 1 receptor (GLP-1R) and glucagon receptor (GCGR) are emerging as novel therapeutics for the treatment of type 2 diabetes mellitus (T2DM) patients with obesity. Our previous work identified a Xenopus GLP-1-based dual GLP-1R/GCGR agonist termed xGLP/GCG-13, which showed decent hypoglycemic and body weight lowering activity. However, the clinical utility of xGLP/GCG-13 is limited due to its short in vivo half-life. Inspired by the fact that O-GlcNAcylation of intracellular proteins leads to increased stability of secreted proteins, we rationally designed a panel of O-GlcNAcylated xGLP/GCG-13 analogs as potential long-acting GLP-1R/ GCGR dual agonists. One of the synthesized glycopeptides 1f was found to be equipotent to xGLP/GCG-13 in cell-based receptor activation assays. As expected, O-GlcNAcylation effectively improved the stability of xGLP/GCG-13 in vivo. Importantly, chronic administration of 1f potently induced body weight loss and hypoglycemic effects, improved glucose tolerance, and normalized lipid metabolism and adiposity in both db/db and diet induced obesity (DIO) mice models. These results supported the hypothesis that glycosylation is a useful strategy for improving the in vivo stability of GLP-1-based peptides and promoted the development of dual GLP-1R/GCGR agonists as antidiabetic/antiobesity drugs.
Mice ; Animals ; Glucagon-Like Peptide 1/metabolism* ; Receptors, Glucagon/therapeutic use* ; Xenopus laevis/metabolism* ; Diabetes Mellitus, Type 2/drug therapy* ; Glycopeptides/therapeutic use* ; Obesity/drug therapy* ; Hypoglycemic Agents/pharmacology* ; Peptides/pharmacology*

OBJECTIVE: To compare the biomechanical differences among the five internal fixation modes in treatment of Day type Ⅱ crescent fracture dislocation of pelvis (CFDP), and find an internal fixation mode which was the most consistent with mechanical principles. METHODS: Based on the pelvic CT data of a healthy adult male volunteer, a Day type Ⅱ CFDP finite element model was established by using Mimics 17.0, ANSYS 12.0-ICEM, Abaqus 2020, and SolidWorks 2012 softwares. After verifying the validity of the finite element model by comparing the anatomical parameters with the three-dimensional reconstruction model and the mechanical validity verification, the fracture and dislocated joint of models were fixed with S ₁ sacroiliac screw combined with 1 LC-Ⅱ screw (S ₁+LC-Ⅱ group), S ₁ sacroiliac screw combined with 2 LC-Ⅱ screws (S ₁+2LC-Ⅱ group), S ₁ sacroiliac screw combined with 2 posterior iliac screws (S ₁+2PIS group), S ₁ and S ₂ sacroiliac screws combined with 1 LC-Ⅱ screw (S ₁+S ₂+LC-Ⅱ group), S ₂-alar-iliac (S ₂AI) screw combined with 1 LC-Ⅱ screw (S ₂AI+LC-Ⅱ group), respectively. After each internal fixation model was loaded with a force of 600 N in the standing position, the maximum displacement of the crescent fracture fragments, the maximum stress of the internal fixation (the maximum stress of the screw at the ilium fracture and the maximum stress of the screw at the sacroiliac joint), sacroiliac joint displacement, and bone stress distribution around internal fixation were observed in 5 groups. RESULTS: The finite element model in this study has been verified to be effective. After loading 600 N stress, there was a certain displacement of the crescent fracture of pelvis in each internal fixation model, among which the S ₁+LC-Ⅱ group was the largest, the S ₁+2LC-Ⅱ group and the S ₁+2PIS group were the smallest. The maximum stress of the internal fixation mainly concentrated at the sacroiliac joint and the fracture line of crescent fracture. The maximum stress of the screw at the sacroiliac joint was the largest in the S ₁+LC-Ⅱ group and the smallest in the S ₂AI+LC-Ⅱ group. The maximum stress of the screw at the ilium fracture was the largest in the S ₁+2PIS group and the smallest in the S ₁+2LC-Ⅱ group. The displacement of the sacroiliac joint was the largest in the S ₁+LC-Ⅱ group and the smallest in the S ₁+S ₂+LC-Ⅱ group. In each internal fixation model, the maximum stress around the sacroiliac screws concentrated on the contact surface between the screw and the cortical bone, the maximum stress around the screws at the iliac bone concentrated on the cancellous bone of the fracture line, and the maximum stress around the S ₂AI screw concentrated on the cancellous bone on the iliac side. The maximum bone stress around the screws at the sacroiliac joint was the largest in the S ₁+LC-Ⅱ group and the smallest in the S ₂AI+LC-Ⅱ group. The maximum bone stress around the screws at the ilium was the largest in the S ₁+2PIS group and the smallest in the S ₁+LC-Ⅱ group. CONCLUSION For the treatment of Day type Ⅱ CFDP, it is recommended to choose S ₁ sacroiliac screw combined with 1 LC-Ⅱ screw for internal fixation, which can achieve a firm fixation effect without increasing the number of screws.
Adult ; Male ; Humans ; Finite Element Analysis ; Fracture Fixation, Internal/methods* ; Fractures, Bone/surgery* ; Pelvis ; Spinal Fractures/surgery* ; Fracture Dislocation/surgery* ; Joint Dislocations/surgery* ; Biomechanical Phenomena