BACKGROUND:The biomechanical effect of the implant-bone interface is one of the most important factors for bone resorption. The new structure of the periodontal-ligament-like implants may improve the distribution of the interfacial stress. OBJECTIVE:To discuss the effect of the internal structure changes of traditional implants on the cortical bone stress distribution and peak at the implant-bone interface under different occlusal load conditions, so as to provide a theoretical basis for the optimization design and clinical application of new structure implants. METHODS:Two kinds of digital models, new structure implant (model A) and non-threaded cylindrical implant (model B), were established by Pro/ENGINEER software. Variations of the stress peak and stress distribution of implant-bone interface cortical bone area under the same bone and force environment were analyzed using Ansys software. RESULTS AND CONCLUSION: Under a vertical loading, the stress peak under different forces was reduced by 17.54% in model A compared with model B; under a 45° loading, the stress peak of model A was reduced by 2.59% compared with model B, and it showed an evident tendency of high stress area focusing to the buccal side of model B. Under the chew-simulation loading, the stress peak of model A was lower than that of model B. The biggest difference (0.353 2 MPa) appeared atβ=12°(β is the angle of force direction and the implant axis), and it gradualy reduced atβ > 12°. At the same time, model A had a wider range of application degree compared with model B in two quantitative indicators, including optimal peak stress of promoting bone tissue growth and stress peak of maintaining healthy bone tissue. These results suggest that the optimized structure of implants contributes to improve the cortical bone stress distribution at the implant-bone interface, decrease the peak stress, and reduce the risk of cortical bone absorption in a wider range.

Cancer stem cells comprise a sub-population with the capacity of self-renewal,self-differentiation and high tumorigenicity.Cancerogenesis,development,relapse and therapeutic resistance are closely related with these cells.The most important characteristics of these cells are the ability to self-renew.So insight into the regulating mechanism of self-renewal in cancer stem cells will be important for the development of novel molecular agents targeted the cancer stem cells.

Carthamus tinctorius L. is a traditional Chinese medicine with the effect of promoting blood circulation and removing blood stasis. HSYA (hydroxysafflor yellow A) is the main effective component of Carthamus tinctorius L. In order to study the inhibitory effects of HSYA against PMN (polymorphonuclear) activation induced by LPS (lipopolysaccharide), rabbit PMN adhesion potency which was activated by LPS through colorimetry method was observed. Cellular free calcium concentration was determined by fluorescence spectrophotometry. RT-PCR was applied to study the effect of HSYA on PMN TNF-alpha and IL-6 mRNA expression; The inhibition of HSYA on NF-kappaB activation was monitored with immunofluorescence. The results showed that after treated with HSYA, the increase of adhesion potency (HSYA dose 1.01 x 10(-4) mol x L(-1)), free calcium concentration (HSYA dose 3.1 x 10(-5) mol x L(-1)), TNF-alpha and IL-6 mRNA expression elevation (HSYA dose 5.2 x 10(-1) mol x L(-1)) induced by LPS were inhibited. HSYA can inhibit NF-kappaB p65 subgroup nuclear translocation (HSYA dose 5.2 x 10(-5) mol x L(-1)). It is suggested that HSYA is effective in PMN activation induced by LPS.

This study is to investigate the pharmacological effect and mechanism of action of hydroxysafflor yellow A (HSYA) on acute lung injury (ALI). The rat ALI was induced by oleic acid and lipopolysaccharide (LPS) injection. The incidence of acidosis, PaO2 (arterial blood oxygen pressure), W/D (wet weight/dry weight) and lung index (LI) were measured. Electron microscope and optical microscope were applied to observe lung morphological changes in rat. RT-PCR was used to determine TNF-alpha and ICAM-1 mRNA level. Inhibition effect of HSYA on plasma inflammatory cytokine expression was measured by ELISA. HSYA could alleviate pulmonary edema, reduce acidosis, keep PaO2 from descending, inhibit inflammatory cell infiltration, inhibit rat lung TNF-alpha and ICAM-1 mRNA expression and plasma IL-6 and IL-1beta level elevation. HSYA is an effective ingredient to remit ALI induced by oleic acid and LPS in rat.

Objective The purpose of the present study is to compare the pharmacokinetic and biodistribution properties of 99Tcm N-mercaptopyridine-N-oxide (99 Tcm N-MPO) with 99 Tcm-sestamibi (99 Tcm-MIBI) in normal dogs, and to investigate the potential of 99TcmN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Twelve healthy mongrel dogs were injected intravenously with 99TcmN-MPO (n = 6) or 99Tcm-MIBI (n = 6). Tracer kinetics in body fluids were determined by collecting blood of 1 ml via a femoral vein catheter at 30 s, 1,2,3,4,5, 10, 20, 30, 40, 60and 90 min post-injection (p. i.). The collected blood samples were weighed and counted for radioactivity in a γ-counter. Anterior and posterior planar γ-camera images were collected at 10, 20, 30, 60, 90, and 120 min after injection, with organ uptake quantified by region-of-interest (ROIs) analysis. For comparison, 99Tcm-MIBI was also evaluated in the same twelve dogs. Canine infarct models were set up by micro-invasive interventional embolization. SPECT images in the canine infarct model were collected 24 hours after myocardial infarction at 30 min and 60 min after the administration of 99Tcm N-MPO (n = 5) or 99Tcm-MIBI (n = 5). Results Both of 99Tcm N-MPO and 99Tcm-M1BI had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min [99TcmN-MPO: (35. 77 ± 6. 31)% ID/mg ,99Tcm-MIBI (34. 46 ± 6. 83) % ID/mg] and less than 5% at 30 min p. i. [99Tcm N-MPO(3. 11 ± 1.44) % ID/mg,99Tcm-MIBI (2.93 ±0. 39)% ID/mg] . After injection, 99TcmN-MPO showed significant accumulation in the myocardium and prolonged retention. This rapid liver clearance of 99TcmN-MPO led to favorable heart-to-liver ratios, reaching values of 0. 54 ±0. 06 at 10 min, 1.02 ±0. 06 at 30 min, and 1.38 ±0. 06 at 60 min p. i.In contrast, the heart/liver ratio of 99Tcm-MIBI remained low at all time points (0. 46 ± 0. 03 at 10 min,0. 63 ±0. 03 at 30 min, and 0. 62 ± 0. 12 at 60 min p. i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of 99TcmN-MPO, but not 99Tcm-MIBI. Conclusion The combination of high heart uptake and rapid liver clearance makes 99TcmN-MPO a promising new radiotracer for myocardial perfusion imaging.

Objective To understand the histological characteristics of the major endocrine organs of tree shrew , and provide a normal histological atlas of endocrine organs of tree shrew .Methods Ten artificially fed healthy tree shrews were killed and dissected after anesthesia .The thyroid, parathyroid, adrenal and pituitary glands were observed by gross inspection and samples were taken for routine histological examination with HE staining .Results ( 1 ) The thyroid gland was pale yellow, located on both sides of the 2-4 tracheal rings.The thyroid gland was plate-shaped, its surface was covered with a thin fibrous capsule . The thyroid parenchyma was divided into several lobules by stretched capsule membrane .Follicular and parafollicular cells were distributed in the lobules , and red colloid was present in follicular cavity.(2) Each side had one parathyroid , located on the cranial or the outer surface of the middle part of the thyroid gland, and was slightly covered by thyroid .The gland was round or oval , and its parenchyma was made up of the principal cells and eosinophil cells , and acinar structure appeared in the parenchyma .( 3 ) The adrenal glands were oval , yellow color, located in the renal hili , and linked to the kidneys .They were surrounded by a thin capsule .The parenchyma was divided into cortex and medulla .The cortex was divided into zona glomerulosa , zona fasciculata and zona reticularis from outside to inside.The zona glomerulosa was the thickest layer and the zona fasciculata was the thinnest .The medulla cells formed clumps or mesh, with central vein in the central part .(4) The pituitary gland was located in the sella turcica , with no recessus hypophysis .The pituitary gland was composed of the adenohypophysis and neurohypophysis .Its surface was covered with a connective tissue capsule .The pituitary gland was divided into distal part , middle part and pars tuberalis . neurohypophysis was made up of neural and pars infundibularis .Conclusions The histological atlas of endocrine organs in the tree shrew is established , which is close to that of the primate animals in the morphology , and provide histological evidence for the study of tree shrew endocrine organs and disorders , as well as the animal model of human diseases .

Objective To screen out specific microsatellite markers for use in Tupaia belangeri chinensis genetic testing. Methods Firstly to screen about 700 microsatellite loci from whole genome.Secondly to choose about 100 better loci without defect factors.Lastly 46 primers were designed by 33 tree shrew’ s microsatellite loci obtained from whole genome and other references.Agarose gel electrophoresis and polyacrylamide gel electrophoresis were used for PCR products, and better loci based on electrophoresis results were chosen.Then STR scan was used to select the microsatellite loci combination for genetic testing.Results Twenty-two microsatellite loci were selected with a significant Stutter peak on STR scanning.Comparing the alternative loci and ultimately selected loci, there were two loci available in the five alternative loci of T.glis.The coincidence rate between T.glis and T.b.chinensis was 40%.There were two loci available in the five alternative loci of T.minor, and the coincidence rate between T.minor and T.b.chinensis was 40%.There were two loci available in the three alternative loci of T.belangeri, and the coincidence rate between T.belangeri and T.b. chinensis was about 70%.Conclusions The 22 microsatellite loci screened in this study are well applied for genetic testing of Tupaia belangeri chinensis, therefore, provide a scientific basis for the genetic quality monitoring of tree shrews.

Objective To study the isolation,culture, adipogenic and osteogenic induction Tupaia bone marrow mesenchymal stem cells(BM-MSCs).Method The BM-MSCs from tupaia were isolated and expended by combination of gradient centrifugation and adherence culture , then subcultured and observed for morphology under inverted phase contrast microscope.BM-MSCs were induced to adipocytes .and osteoblasts in vitro Result Cells were spindle or triangle-shaped, and clone proliferation .Cells were successfully induced into adipocytes .and osteoblasts Conclusions The method of isolation BM-MSCs from tupaia by combination of gradient centrifugation and adherence culture is simple and feasible , BM-MSCs have differentiation potential into adipocytes and osteoblasts .

OBJECTIVE: To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. MATERIALS AND METHODS: One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m², sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. RESULTS: The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). CONCLUSION: Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.
Angiography* ; Arteries ; Contrast Media ; Coronary Artery Disease ; Coronary Vessels ; Heart Rate ; Humans ; Noise ; Prospective Studies ; Signal-To-Noise Ratio

OBJECTIVE: To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. MATERIALS AND METHODS: One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m², sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. RESULTS: The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). CONCLUSION: Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.
Angiography* ; Arteries ; Contrast Media ; Coronary Artery Disease ; Coronary Vessels ; Heart Rate ; Humans ; Noise ; Prospective Studies ; Signal-To-Noise Ratio