BACKGROUND: The design of the microstructure of human bone is in fact to construct a model, which could characterize the connecting-porosity cell frame structure. As the porosity structure is represented as irregular curve, and this irregularity has close relationship with the bone function, does the fractal theory effectively find the irregularity containing in the irregular structure?OBJ ECTIVE: To analyze the microstructure of human bone by applying the fractal property, and construct the 3D model that has structural similarity to the natural bone. With the help of Rapid Prototyping technology, a new bionic technique instead of traditional modeling method is presented to model artificial human bone.DESIGN: Computer aided bionic design.SETTING: Biomaterials and Engineering Center of Wuhan University ofTechnoiogy.MATERIALS: The experiment was carried out in the Biomaterials and Engineering Center of Wuhan University of Technology from January to June 2005. The material is the original gray chart of hip joint of one healthy middle-aged male.METHODS: The contour of the human bone microstructure was obtained by exaltation and extraction of the grey chart.B-spline technique was used for vectorization. ①The fractal theory was adopted to compute the fractal dimension of typical aperture structure and the result was represented by dimensions (D=2s, s is the slope of fitting line) to find the inherent relation among apertures. ② Monte Carlo method was used to generate the two-dimensional model of microstructure of bone with the appropriate porosity. The 3D model was manufactured by rapid prototyping technology.MAIN OUTCOME MEASURES: ①Fractal dimension of porous structure of human bone; ② Results of 2D and 3D model of the microstructure of human bone.RESULTS: ①The fractal dimensions of some representative apertures were between 1.14and 1.28. The fractal dimensions of these micro-apertures are rather close, which testified the self-similarity in the edge contour of the microstructure of human bone. ②3D model was generated by cumulating the plane model layer by layer with the rapid prototyping technology. If the high porosity of plane model was ensured, the porosity and connectivity of 3D model could meet the high requirement. Through the computer simulating, the porosity of the model was greater than 40%, which meets the design requirement.CONCLUSION: Fractal theory is applied in the construction of 2D model of human bone based on the requirements in bionic design of the microstructure model of human bone. The fractal characteristics of the grey chart of human bone and the edge contourof its typical micropore are analyzed. The software suitable for 2D tissue engineered bionic microstructure of human bone is developed with VC++, meanwhile, 3D cell scaffold model is constructed by cumulating the planer model, which meets the human bone functions.

BACKGROUND:Domestic scholars use the potentiodynamic polarization technique to determine the corrosion potential of the dental aloys, which is used to evaluate the corrosion performance of the lownoble metal. They have discovered that the main reason affecting corrosion resistance is the content of noble metal. OBJECTIVE:To evaluate the corrosion resistance of Ti, Au aloy, Co-Cr aloy, Ti aloy, and Ni-Cr aloy. METHODS: Five aloys were immersed in synthetic saliva solution. The corrosion potential and corrosion current density of the aloys were determined with potentiadynamic polarization technique. RESULTS AND CONCLUSION:The galvanic series of five kinds of aloys were ranged as folows: Au aloy > pure Ti > Ti aloy > Co-Cr aloy > Ni-Cr aloy. Au aloy and pure Ti had more positive potential that were not easy to produce corrosion; Ti aloy and Co-Cr aloy could form stable oxidation film with a strong ability of anti-pitting and crevice corrosion; Ni-Cr aloy potential was more negative and easy to be dissolved. The corrosion current density of five kinds of aloys was ranged as folows: Au aloy < pure Ti < Ti aloy < Co-Cr aloy < Ni-Cr aloy. Au aloy and pure Ti had lowest current density which was 10-8, indicating that the corrosion rate of Au aloy and pure Ti was lower; in contrast, Ni-Cr aloy possessed the maximum corrosion rate. These findings indicate that Au aloy and pure Ti exhibit a very high corrosion resistance. The corrosion rate of Ni-Cr aloy is the highest; therefore, Ni-Cr aloy is the least acceptable material for implant suprastucture.

Stroke is one of the major diseases that threaten human health, early diagnosis and treatment are very important for stroke. Carotid intima-media thickness (CIMT) is measured noninvasively to diagnosis stroke, and it is a independent predictor for stroke because its thickening can timely predict the incidence and development of stroke. As an important predictor of cardiovascular disease, more and more attention is played on CIMT. In this review, we will make a summary on the important role of CIMT in stroke and the mechanisms of carotid intima-media thickening in stroke as well as the potential use of traditional Chinese medicine in treating carotid intima-media thickening.
Animals ; Carotid Arteries ; drug effects ; physiopathology ; Carotid Intima-Media Thickness ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Stroke ; diagnosis ; drug therapy ; physiopathology

Objective: To compare the pharmacokinetics and relative bioavailability of rapid oral disintegrating tablet of dimenhydrinate (RODTD) and those of market available tablet of dimenhydrinate (DMH). Methods: Eight healthy volunteers were evenly randomized into 2 groups, one group received RODTD (25 mg) and the other received available market tablet of dimenhydrinate (25 mg). The blood levels of DMH were determined by high performance liquid chromatography (HPLC) before and after drug administration in 2 groups. Chromatography conditions were: Nova-Pak C18 as chromatographic column, methanol triethylamine buffer (1 : 1),flow rate: 1.0 ml/min, detection wavelength: 225 nm, and room temperature. The pharmacokinetics and relative bioavailability of RODTD and market available tablets were investigated. Results: The standard curve of DMH in the blank plasma was linear within the range of 5-500 ng/ml, with the regression equation being C=0.004 4 A+4.745 and R2=0.996. The limit of detection was 2 ng/ml; the average recovery rate was (90.55±4.69)% and the RSD was 0.041%. The intra-day derivations of 3 different concentrations (low, middle, and high) of plasma were 9.27%, 4.93%, and 2.95%, respectively (n=5), and the inter-day derivations were 9.97%, 3.81%, and 3.06%, respectively (n=5). Blood samples (3 ml) were subjected to HPLC assay and significant difference was found between the 2 forms of DMH. The pharmacokinetic parameters of RODTD were: AUC=(602.04±113.82) ng • h • ml-1, Cmax=(95.86±21.28) ng • h • ml-1, and TPeak=(1.8±0.32) h; the pharmacokinetic parameters of market available tablets were: AUC=(342.73±84.96) ng • h • ml-1 Cmax=(46.34± 10.32) ng • ml-1, and TPeak=(2.65±0.24) h. Statistical analysis showed there was significant difference in the relative bioavailability of 2 forms of DMH(P<0.01). The relative bioavailability of RODTD to market tablet was 175.66%. Conclusion: The developed RODTD can obviously increase the relative bioavailability of DMH.

Objective To compare the therapeutic effect of routine dose of calcitriol and large dose impulsion therapy on hemodialysis patients with secondary hyperparathyroidism(SHPT). Methods 48 uremic hemodialysis patients were divided into group A(routine group, n = 22) and group B(control group, n = 21 ). In group A,22 pa-tients were administered with calcitriol for 6 months at the dosage of 0.25～0.5μg/d,adding calcium agents simul-taneously;the patients in group B were not given calcitriol for economic reason. In group C,21 patients were given calcitriol twice a week at the dosage of 2μg/time after hemodialysis for 3 months. Results Comparing to group B,serum PTH,AKP in group A had no significant difference,but serum hypocalcium and hyperphasphate were partly corrected,symptoms of bone pain, muscular convulsion and akin pruriter were improved. Comparing to group A,serum hypocalcium and hyperphasphate in group C were corrected, serum PTH, AKP were significantly decreased( t=2.031,P<0.05;t =3.317,P<0.001),and no hypercalcium oecurred. Conelosion Routine dose of calcitriol can not control uremic-SHirr,while impulsion therapy with lower dose oral calcitriol is effective and safe.

0.05).Except that the wet weight of the epididymis in high-dose group of apigenin was significantly different compared with middle-dose group of apigenin(P 0.05).Cell cycle analysis showed that compared with the negative control group,the percent of diploid cells in low and high-dose group was decreased,the proportion of G0/G1 phase cells in low-dose group of apigenin was reduced(P

Objective To evaluate the effect and mechanism of HMG-CoA reductase inhibitor simvastatin on experimental interstitial fibrosis. Methods Experiments on rat 5/6 nephrectomy chronic renal failure model and primary cultured renal interstitial fibroblast cells were conducted in this study. The cell proliferation, extracellular matrix, c-fos mRNA expression of rat interstitial fibroblasts were measured by MTT assay, immunohistochernitry, semi-quantitative reverse-transcript PCR methods, respectively. Results Serum cholesterol, triglyceride and creatinine of treated group were significantly reduced by simvastatin as compared with controls. No statistical significance in BUN was observed between untreated and simvastatin-treated rats. Histological examination revealed that simvastatin caused a reduction in the glomeruli with sclerosis. Tubulointerstitial injury paralleled the degree of glomerular damage. Simvastatin in a dose-dependent manner inhibited the proliferation of renal intersititial fibroblasts, decreased the secretion of lamimn( LN), and suppressed the expression of c-fos mRNA, as compared with normal controls. No obvious effect on hyaluronic acid( HA) secretion of fibroblasts was found. Conclusions Simvastatin is anti-proliferative in interstitial fibroblasts and decreases the secretion of laminin. This effect is exerted, at least in part, via inhibition of the c-fos and c-jun-dependent mitogenic pathway. Simvastatin may prevent interstitial fibrosis development and attenuate renal damage in uremic rats with hvperlipidemia.

AIM: To observe the antifungal action of Huanglian Pikang tincture (HPT). METHODS: An anifungal experiment was performed in vitro. RESULTS: HPT had obvious antibacterial actions for the trichophyton rubrum, T. interdigital, epidermophyton floccosum, candida albicans and lessened the colonies (n=5, P

Adult ; Anemia, Aplastic ; complications ; surgery ; Female ; Hematopoietic Stem Cell Transplantation ; Hemoglobinuria, Paroxysmal ; complications ; surgery ; Humans

Objective To investigate the necessary and feasibility of fistulous tissue-saving anorectoplasty for low anorectal malformation with fistula in children.Methods The clinical data of 67 cases of low anorectal malformation with fistula were analyzed retrospectively, there were 59 girls with rectovestibular fistula, 8 boys with rectoperineal fistula. The patients′ average age were 10 months, ran -ging from 3 months to 16 years. The clinical manifestations of all patients were intractable constipation, or out of position of anus. Cut-back procedure had been performed on 4 patients in infancy. The anterior sagittal anorectoplasty was performed in all cases.Results In all cases returned for follow-up at 3 and 6 months after operation, the longest was 8 years. The postoperative course of 65 patiens was uneventful without wound infection, and had a normal-looking perineum, other 2 cases with anal rupture in operation were with sagittal wound infection resulted from perforation in repairing anus, and formed finally rectoperineal fistula with a normal-looking anus. Sixty-four cases (95.5%) had good continence by 5-6 score, another 3 cases (1 boy, 2 girls) with intractable constipation defecated with help of Glycerinum.Conclusions The fistulous tissue-saving anterior sagittal anorectoplasty is a reliable and feasible procedure for low anorectal malformation with fistula. This operation provides good results.