Objective:To investigate the stress distribution surrounding an implant under different thickness of cancellous bone and cortical bone,and to analyze the influence of thickness ratio and total thickness of bone tissues on the reliability of an implant.Methods:By using the commercial finite element method software Abaqus, a simplified three-dimensional model of a jawbone consisting of a cancellous bone,a cortical bone,an implant,and a ceramic crown was constructed,and then the computation was performed.Under the condition that the system was loaded by lateral and normal stresses, the influence of thickness ratio and total thickness of cancellous bone and cortical bone in the stress distribution surrounding the implant was studied,where the thickness ratios were 3∶1, 2∶1, 1∶1, 1∶2, and 1∶3;the total thickness were 0.5, 1.0, 2.0, 3.0 and 4.0 mm, respectively. Results:The maximum stresses on the cortical bone,the cancellous bone as well as the implant were all found to decrease with the increasing of the total thickness of cortical and cancellous bones,with a higher decreasing rate in the range between 0.5-2.0 mm and a lower decreasing rate between 2.0-4.0 mm. More importantly, the maximum value of stress in the cortical bone within the neck region of the implant was observed to increase dramatically via reducing the total thickness below 2 mm, while it was increased insignificantly when the total thickness was above 2.0 mm. Conclusion:The thickness ratio and the total thickness of cancellous bone and cortical bone have strong influence in the stress distribution surrounding the implant.In dental implantation surgery, the total thickness of cancellous bone and cortical bone should be at least 2 mm, and therefore 2 mm is an optimal value.

Objective To investigate the protective effects of astragalus preconditioning on the tolerance of ischemia time of mouse small intestine . Methods C57BL/6 mice were randomly divided into 5 groups (n = 7): sham operation group (Sham group),intestinal ischemia reperfusion group (IR group) and astragalus preconditioning group (ASIR group). IR group and ASIR group include 2 sub-groups respectively, specifically, 2 h reperfusion was performed 45 min (ASIR1) and 60 min (ASIR1) after blocking superior mesenteric artery. Intestinal terminal morphology was observed by light microscope after HE coloration . Serum levels of LPS , DAO and intestinal mucosa TNF-α were measured by ELISA. Intestinal Cyto C expression were detected by immunofluorescence. Results Astragalus preconditioning reduces Chiu′s score significantly. Expression of Cyto C was significantly down-regulated in astragalus preconditioning groups, and levels of LPS, DAO and TNF-αsignificantly decreased. The damages in IR2 group is obviously severe than in IR1, but there were no significant differences between this two groups after pretreatment with astragalus. Conclusion Astragalus preconditioning has obvious protective effects to intestinal ischemia reperfusion, and enhances the tolerance to longer time of ischemia.

BACKGROUND: Embryonic pancreatic tissue is characterized by its abundance, potent in proliferation & differentiation, and minimal immunological rejection. It is widely considered as potential pancreatic endocrinological stem cells resource for treating diabetes mellitus.OBJECTIVE: To investigate the embryonic mouse pancreatic tissue isolation technique and observe the recipients' blood glucose regulatory effects of the grafted embryonic pancreas in an experimental diabetes mellitus mouse model.METHODS: Pancreatic tissue from C57B1/6 mouse embryos at embryonic days 11.5-16.5 was isolated under the stereomicroscope. C57BL/6 mouse models of streptozocin-induced diabetes mellitus were established and then randomly divided into two groups: transplantation group, in which, five pieces of pancreatic tissue of mice at embryonic 16.5 days were transplanted into mouse renal capsule, and sham-operated control group, in which, 0.05 mL RPMI1640 culture medium was injected into mouse renal capsule. When blood glucose level of the transplantation group mouse was≤ 11.2 mmol/L, the endocrine function of embryonic pancreatic tissue transplanted was detected by IPGTT and IPITT methods and then the transplanted graft was removed for observing the blood glucose relapse.RESULTS AND CONCLUSION: Nearly intact pancreatic tissue of mice at embryonic days 11.5-16.5 could be isolated through the use of stereomicroscope. Pancreatic tissue morphology and color of mice ≤ embryonic 12.5 days were difficultly distinguished from adjacent tissue and they could only be isolated carefully according to the relationship with adjacent organs. Pancreatic tissue of mice > embryonic 12.5 days exhibited initial endocrinological tissue morphology mimic white cauliflower. Histological and ELISA examinations showed that embryonic pancreatic tissue could express and secrete insulin and the insulin level was gradually increased with developmental time. Embryonic pancreatic tissue could grow beneath the recipient renal capsule. The insulin and glucagon expression in the post-transplantational pancreatic tissue graft was increased compared with prior to transplantation. These results suggest that pancreatic tissue is a potential stem cell resource for treating the diabetes mellitus.

Adult ; Aneurysm, Dissecting ; complications ; Aortic Aneurysm ; complications ; Humans ; Lower Extremity ; physiopathology ; Male

Animals ; Cardiovascular Diseases ; etiology ; Cerebrovascular Disorders ; etiology ; Homocysteine ; metabolism ; Humans ; Methylenetetrahydrofolate Reductase (NADPH2) ; genetics ; Polymorphism, Genetic

OBJECTIVETo understand the prevalence and risk factors for suicidal ideation among college students and to provide a scientific basis for promoting psychological health and suicide prevention.

METHODS623 college students at Central South University were selected using stratified cluster sampling and administered a suicide ideation questionnaire, a Symptom Check List (SCL-90), an Adolescent Self-Rating Life Events Check List (ASLEC), a Social Support Rating Scale (SSRS) and a questionnaire about background information. Multivariate logistic regression analysis was employed to identify risk factors for suicide ideation.

RESULTSOne year prior to our investigation, 14.6% of respondents had suicide ideation, 2.5% had made a specific suicide plan, and 1.8% had made a suicide attempt. The main risk factors for suicide ideation were dissatisfaction with the selected major of study, limited social support, recent negative life events and depressive tendency.

CONCLUSIONSThe prevalence of suicide ideation among these college students was high. Appropriate measures focusing on the risk factors identified in this study should be urgently developed to prevent suicides in college students.

China ; Female ; Humans ; Logistic Models ; Male ; Risk Factors ; Students ; psychology ; Suicide, Attempted ; psychology ; statistics & numerical data ; Surveys and Questionnaires ; Universities

Objective To investigate the expressions of intermedin /adrenomeduliin 2 (IMD/AM2) and its receptor calcitonin receptor-like receptor (CRLR) in the kidney of rats after renal ischemia reperfusion injury(IRI). Methods Male Wistar rats were divided randomly into two groups: sham group and operation group. Renal IRI model was induced by clamping both renal arteries. Blood and kidney were harversted at 0 h, 6 h, 12 h, 24 h, 48 h, 72 h after reperfusion, respectively. Renal histological changes were semi-quantitated. Expressions of IMD and CRLR in the kidney were detected by Western blot, and the content of IMD in serum was measured by radioimmunity at 12 h, 48 h, 72 h after repeffusion. Results Kidneys of renal IRI model rats displayed significant pathologic changes, and the changes were much severer at 48 h after reperfusion. The expressions of IMD and CRLR in kidney were significantly up-regnlated at 12 h, 48 h, 72 h after renal IRI (P<0.01). The level of IMD in serum increased at 12 h, 48 h, 72 h after renal IRI (P<0.05). Conclusion The expressions of IMD and its receptor are up-regulated in the kidney after renal IRI, which may participate in the pathophysiological changes induced by renal IRI.

Objective To construct eukaryotic expression vector encoding rat IMD gene and deliver it into rat renal tissue via ultrasound-mircobubbles. Methods IMD gene was inserted into pCDNA3.1 ( + )between Hind Ⅲ and EcoRI enzyme sites. The recombinant plasmid designated as IMD-pCDNA 3.1 wasconfirmed by restrictive enzyme digestion and sequencing. Eighteen male Wistar rats were randomized into 3groups, which were treated with no transfection, empty vector transfection and IMD transfection, respectively, in renal tissue via ultrasound-microbubbles. RT-PCR and Western blotting were applied to detect the expression level of IMD. Results Enzyme- digestion and sequencing data showed that IMD-pCDNA 3.1 was correctly constructed. The differences in ALT, AST, BUN and SCr were not significant; No obvious damage in the glomerular, tubular and interstitial was observed in all the treated groups;Compared with non-transfection group and empty vector-transfection group, IMD mRNA and protein expression in IMD transgenic renal tissue were significantly increased. Conclusion IMD-pCDNA 3.1 expression vector was successfully constructed and well expressed in rat kidney.

Objective To investigate the diagnostic and prognostic value of serum soluble CD163 (sCD163 )and the positive rate of membrane -bound CD163 (mCD163 )in peripheral blood mononuclear cells (PBMC)in children with infection -associated hemophagocytic syndrome (IAHS).Methods Between July 2012 and June 2016,26 pediatric patients with IAHS (IAHS group)and 28 pediatric patients with sepsis(sepsis group)admitted to Children′s Hospital Affiliated to Shanghai Jiaotong University were selected,and 20 healthy children were taken as healthy control group. Sandwich enzyme linked immunosorbent assay was used to detect serum sCD163 .The population of circulating mCD163 positive monocytes was determined by using flow cytometry.Receiver operating characteristic (ROC)curves were used to evaluate the diagnostic and prognostic values of sCD163 and mCD163 in children with IAHS compared with the diagnos-tic and prognostic values of plasma ferritin,and so on.Results The serum levels of sCD163 in patients of IAHS group, sepsis group and healthy control group were (1264 ±538)mg/L,(862 ±332)mg/L,(610 ±316)mg/L,respective-ly.And the population of mCD163 -positive PBMC in patients of IAHS group,sepsis group and healthy control group was (88.3 ±9.7)%,(68.5 ±18.3)%,(28.9 ±5.2)%,respectively.Both serum sCD163 and the population of mCD163 -positive PBMC were significantly higher in IAHS group compared with those of sepsis group (t =2.031 ,P =0.048;t =3.191 ,P =0.002,respectively).The serum sCD163 and population of mCD163 -positive PBMC in sepsis group were higher than controls (t =3.848,P =0.002;t =4.049,P =0.000,respectively).Moreover,the areas under the ROC curve (AUC)for the mCD163 ,sCD163 ,were 0.853(P =0.013),0.762(P =0.004),0.755(P =0.049),respec-tively.mCD163 at a cutoff of 83.7% had a high diagnosis sensitivity (81 .8%)and specificity (72.4%).The optimal cutoff values of sCD163 and ferritin for predicting IAHS was 888 mg/L (sensitivity 66.7% and specificity 63.3%)and 2880 μg/L (sensitivity 80.0% and specificity 54.5%).In addition,the serum level of sCD163 and the population of mCD163 -positive PBMCs were significantly increased in acute phase and decreased in recovery phase[(1553 ±542) mg/L vs.(866 ±92)mg/L,(91 .0 ±6.4)% vs.(79.0 ±4.6)%,t =2.450,χ2 =3.419,P =0.036,0.007]in IAHS group.Furthermore,subgroup analysis indicated that the serum level of sCD163 and the population of mCD163 -positive PBMCs were significantly higher in dead patients than those in survived patients [(1748.91 ±518.17)mg/L vs. (909.69 ±171 .35)mg/L,t =3.070,P =0.011 ;(93.50 ±8.42)% vs.(77.30 ±3.28)%,χ2 =3.005,P =0.024, respectively].Conclusion Serum sCD163 and the population of mCD163 -positive PMSCs are specific and validity bio-markers for early diagnosis of IAHS,which also are associated with treatment response assessment and prognostic analy-sis in IAHS.

A strain of cellulolytic bacterium was isolated from soil by cellulostic plate. The morphological and physiological properties of this strain were studied. According to Bergey's Manual of Determinative Bacteriology ,the strain was identified as a new strain of the Sporocytophaga.