Rapid prototyping technology, a kind of novel digital prototyping technology developed in mid-1980s based on a principle of discrete and accumulation, which fabricates a prototype by accurate accumulation of material according to the CAD models or CT data under the control of the computer without any other device. In recent years, it has shown a great application prospect in the field of orthopedics combined with three-dimensional image reconstruction of spiral CT and MRL In this article, review is given on the application development of rapid prototyping technology in orthopedics, such as organ model preparation and surgical planning, customized implant and bone tissue engineering porosity scaffold fabrication.

Myasthenia gravis is autoimmune diseases which mediated with acetylcholine receptor antibody.Based on the studies in rencent years,treatment of MG has made great progress.Thisreview will discuss several aspects,such as immune tolerance induced by dendritic cells,blocking monoclonal antibodies,hematopoietic stem cell transplantion,and provide new ideas and methods for the treatment of myasthenia gravis.

Implant drug delivery system(IDDS) is helpful to the therapy of infection、tuberculosis and tumor of bone. With the development of tissue engineering, various materials has been used as the carriers for the IDDS. Research of the carrier materials used in implant drug delivery system is reviewed in this article.

As an essential element of tissue engineering,the shape,pore size,and porosity of the porous scaffolds have direct influence on the attachment,proliferation,and differentiation of seeding cell as well as their properties.So it is important to be able to prepare an ideal porous scaffold which is able to provide the cells with an excellent micrcenvirenment in order to support their growth and differentiation.In this article,we reviewed some kinds of the preparation technologies of the porous scaffolds for tissue engineering,including fiber bonding,emulsion freeze drying,solvent casting/particulate leaching,high-pressuro processing,gas foaming/particulate leaching,thermally induced phase separation,and electro-spinning,with focus on rapid prototyping.It is our belief that the combination of the basic technologies and the rapid prototyping technology which is able to control the properties of the scaffolds and could be applied for individualized scaffold construction would be the major focus of research in the future.

Objective To evaluate the biocompatibility of porous drug implant scaffolds prepared by 3D printing technique. Methods Porous drug implant scaffolds were fabricated by 3D printing technique, and a series of tests were carried out to validate the biocompatibility, including acute systemic toxicity, hot source test, local irritation reaction, micronucleus test, muscle implant test and so on. Results The porous drug implant scaffolds showed no acute systemic toxicity, no pyrogenetic effect, no local erythema and edema in local irritation re-action, hemolysis rate of 0.29%, no cellular genetoxic. No local tissue denaturation, necrosis and exclusion were found in intramuscular implant test. Conclusion With good biocompatibility, the porous drug implant scaffold fabricated by 3D printing technique can meet the clinical requirement for biomaterial.

Objective To study the practical value of serum prealbumin and butyrylcholinesterase in Child-Pugh classification of liver cirrhosis. Methods 66 serum samples of patients with liver cirrhosis and 50 serum samples of the healthy subjects were collected for detecting prealbumin (PA) level and butyrylcholinesterase (BuChE) activity, as well as hepatic functional indices(serum albumin, total bilirubin and alanine aminotransferase). The patients were classified according to the Child-Pugh score. Results Compared with healthy subjects, the content of PA and the activity of BuChE significantly decreased in the patients with liver cirrhosis. According to the Child-Pugh classification, PA content and BuChE activity in different grades of liver cirrhosis varied obviously. Conclusion The content of serum PA and the activity of serum BuChE had an important guiding significance in diagnosing the extent of liver cirrhosis, which can serve as effective indices for diagnosis of patients'condition and prognostic evaluation of liver cirrhosis.

Objective To investigate the effects of ghrelin on colonic motility in mice.Methods The eflfects of ghrelin on colonic propulsive movement were detected by charcoal suspension pushing test after injection of normal saline and different doses of ghrelin(20,50,100,200 ng/g).The effects of atropine,NG-nitro-L-arginine methylester hydrochloride(L-NAME)or D-Lys3-GHRP-6 on the changes of colonic propulsive movement caused by ghrelin(100 ng/g)were also investigated.In vitro,the effects of different doses of ghrelin(0.01,0.1,1,10μmol/L)on the spontaneous contraction amplitude of proximal colonic circular muscle strips were studied.Results Ghrelin significantly accelerated the colonic propulsive movement in dose-dependent manner,but the efiect was significantly inhibited in the presence of atropine,L-NAME or D-Lys3-GHRP-6(t=10.230,12.560,11.590,P＜0.05).Administration of ghrelin significantly increased the contraction amplitude of colonic circular muscle strips.but this effect was inhibited when the colonic circular muscle strips were pretreated by tetrodotoxin.ConclusionsGhrelin can accelerate colonic propulsive movement by activating growth hormone secretagogue receptor of cholinergic excitatory pathways and nitrergic nervous pathways in the enteric nervous system of colon.

Research collaboration and interdisciplinary integration is anecessary trend of the development of science and technology,and is especially true in biomedical field.This paper describes the interdisciplinary practice of the projects at Peking University Health Science Center in recent years.Problems and the efficiency of the management is also analysed.

Objective:To evaluate effect of telephone follow-up combined with written instruction on compliance and Helicobacterpylori (H.pylori) eradication in patients with H.pylori infection.Methods:A total of 160 H.pylori positive patients were randomly divided into an experimental group and a control group (n=80 in each group).Ml the patients got the guide instruction named the guidance of clinical medication for H.pylori infection patients before the treatment.The patients in the experimental group were added individualized follow-up with telephone.The compliance,eradication ofH.pylori,adverse events,and satisfaction were compared between the 2 groups.Results:The eradication rate of H.pylori in the perprotocol analysis for the experimental group and control group were 64.4％ (47/73) and 56.5％(35/62),respectively (P=0.380),while in the intention-to-treat analysis,the rates were 58.8％ (47/80) and 43.8％ (35/80,P=0.082),respectively.The compliance rate in the experimental group was significantly higher than that in the control group (91.3％ vs 77.5％,P＜0.05).There was significant difference in patients' satisfaction in good ones (75.3％ vs 51.6％) and poor ones (5.5％ vs 21.0％) between the 2 groups (P＜0.05).There were 11 patients in the experimental group and 36 patients in the control group,who appeared adverse reactions such as nausea,bad breath,abdominal distention,poor appetite,and defecation habit change during the process of eradicating H.pylori,but the occurrence rate in the experimental group was obviously lower than that in the control group (15.1％ vs 58.1％,P＜0.05).Conclusion:The telephone follow-up cannot increase the H.pylori eradication rate,but it can improve compliance and satisfaction for the patients and relieve adverse effects.

ObjectiveTo investigate the characteristics of growth and secretion in primarily cultured human pheochromocytoma cells.MethodsThe human pheochromocytoma tissues were digested successively,and the tumor cells were cultured.The growth curves of three tumors were plotted by cell count.At the same time,the catecholomine in the medium was measured with high performance liquid chromatography.ResultsThe number of primarily cultured human pheochromocytoma cells increased gradually from first to sixth day after plating,and then the cell number began to decrease from seventh day.The levels of norepinephrine(NE) and epinephrine(E) in the medium of cultured cells significantly decreased on first and second day,and the levels of NE and E had no significant difference on the second to eighth day.The levels of dopamine in the medium had no significant difference on the first to eighth day.ConclusionThe primarily cultured pheochromocytoma cells differentiate obviously after plating,but have no significant proliferation.The levels of catecholomine in the medium are decreased significantly on the first and second day.