OBJECTIVETo modify biomacromolecules, such as chitosan and collagen, to synthesize a mineralized template that will induce self-growing remineralization of tooth enamel.

METHODSNatural polycation polysaccharide chitosan was modified through phosphorylation to synthesize the polyanion derivative ofphosphorylated chitosan. Parent hydrogels com- bined with chitosan and collagen I were built through peptide binding reaction using genipin as a crosslinker. The gels self- assembled on the tooth's inert surface, which was stimulated by ultraviolet radiation. The bionic saliva provided mineralized ion, and then the hydroxyapatite assembled and grew in situ on the tooth.

RESULTSThe functional group P04(3-) (3,446 cm(-1)) was grafted on chitosan as confirmed by the Fourier transform infrared spectroscopy. The porous polyelectrolyte complex hydrogel formed by the interaction between the polycation chitosan and the polyanion phosphorylated chitosan could induce hydroxyapatite crystal nucleation and growth on the hydrogel fiber surfaces. The neonatal crystal was hydroxyapatite as confirmed by X-ray diffraction and was tightly connected to the tooth. A continuous structure of column crystals with sizes ranging from 30 nm to 60 nm was observed. The structure was in parallel direction similar to the direction of the enamel rod, and its hardness was close to dentin.

CONCLUSIONThe parent hydrogels that were easily obtained and controlled could mimic the template of the enamel mineralization and induce a self-growing hydroxyapatite, which is an important step in the structural bionics of enamel.

Biocompatible Materials ; Chitosan ; Collagen ; Dental Enamel ; Durapatite ; Microscopy, Electron, Scanning ; Polymers ; Spectroscopy, Fourier Transform Infrared ; Tooth ; Tooth Remineralization ; Ultraviolet Rays ; X-Ray Diffraction

Abstract: Objective To explore the effects of continuous light and benzene exposure on peripheral blood erythrocyte - Methods parameters and expression of miR 144/451 in the bone marrow of mice. This was a 2×2 factorial design. Photoperiod ， ， factor was set as normal and continuous light levels and mice were treated for 12 hours/12 hours light/dark or 24 hours light - respectively. The benzene exposure factor was set as non exposure and exposure levels. Mice were exposed to benzene by static 3 ， inhalation with a mass concentration of 0.0 and 32.5 mg/m for three hours per day five days per week for a total of four weeks. ， ， Specific pathogen free male C57BL/6 J mice were randomly divided into negative control group simple continuous light group - - ， ， simple benzene exposure group and combined exposure group with 12 mice per group. After benzene exposure peripheral ， blood was collected for the detection of erythrocyte parameters in four periods. After the mice were sacrificed the expression of - - - - miR 451a and miR 144 5p was detected by real time fluorescence quantitative polymerase chain reaction in bone marrow Results （ ）， ， tissues. The hematocrit volume HCT mean corpuscular volume mean corpuscular hemoglobin concentration （ ） - MCHC and mean corpuscular hemoglobin in peripheral blood and the relative expression of miR 451a in bone marrow tissue （ P< ） ， were statistically significant only in mice with benzene exposure all 0.05 . Among them the MCHC of benzene exposed （P< ）， （ P< ） - mice increased 0.05 but the other four indexes decreased all 0.05 compared with non benzene exposed mice. In thenegative control group the change of red blood cells count hemoglobin level and HCT in peripheral blood were rhythmical all P < ） ， （ P > ） rhythmical 0.05 . However the indexes above were out of rhythm all rhythmical 0.05 in the simple continuous light group and the - （ P > combined exposure group. The change of hemoglobin level and HCT of peripheral blood were also out of rhythm all rhythmical ） - - 0.05 in the simple benzene exposure group. The relative expression of miR 451a in bone marrow tissues of negative control （ P < ）， - group and simple continuous light group was rhythmical all rhythmical 0.05 while the relative expression of miR 451a in simple - - （ P > ）Conclusion benzene exposure group and combined exposure group was out of rhythm all rhythmical 0.05 . Benzene exposure ， induced changes in erythrocyte parameters of mice are independent effect and its mechanism may be related to the rhythmic - ， expression disorder of miR 451a in bone marrow tissues. Continuous light exposure benzene exposure and their interactions can ， interfere with the circadian rhythm of erythrocyte parameters such as red blood cell count hemoglobin and HCT to some extent.

The method of homogeneity evaluation for active pharmaceutical ingredient (API) spatial distribution in lyophilized product was investigated for the first time with confocal micro-Raman spectroscopy mapping, using pemetrexed disodium for injection as a model drug. Certain areas of the lyophilized product were scanned to obtain Raman spectra. The classical method ("peak clipping" method) was employed for mapping with characteristic Raman peaks of the API and the excipient. Due to the API being finely dispersed in the excipient in lyophilized products, the classical method cannot discriminate between the two ingredients making the distribution homogeneity difficult to evaluate. The "ratio of characteristic peak intensities" method was then utilized. Using this method, the relative intensity of the characteristic Raman peaks of the API to the excipient was applied for mapping and the relative content of API to excipient was calculated for a homogeneity evaluation of the drug distribution. The validation of this method showed a good linear relationship between the relative intensity and the relative content of API to excipient (r² > 0.99), and the precision and recovery were adequate for homogeneity evaluation of API by Raman spectroscopy mapping. Five products of pemetrexed disodium for injection from different manufacturers were tested through Raman maps applying this method and the histograms of relative Raman intensity were also plotted by frequency to help the homogeneity evaluation of drug distribution. The results showed that there were obvious differences in the drug distribution homogeneity from different products, where a more homogeneous API distribution was found in the brand product. This research provides a reliable method for the homogeneity evaluation of API distribution, which facilitates quality evaluation and process optimization of lyophilized products.

Objective To evaluate the ultrasonic feature and clinical significance of persistent left superior vena cava(PLSVC)in fetal life.Methods Fetal echocardiography was performed in 3368 fetuses.Thirty-one fetuses of PLSVC were confirmed.Results The dilated coronary sinus was observed in 30 of 31 fetuses.Congenital heart defects were presented in 14 of these cases,and extracardiac anomalies were presented in 6 fetuses.Both congenital heart defects and extracardiac anomalies were observed in 4 fetuses.Conclusions PLSVC is always associated with congenital heart defects.The prognosis Of affected fetuses largely depends on whether or not the PLSVC is associated with a congenital heart defect.Prenatal diagnosis of PLSVC can help US plan perinatal counseling and ameliorate the postnatal course.

Objective To explore the clinical feature and gene mutation in steroid 5α-reductase 2 deficiency (SRD5A2). Method The clinical data of SRD5A2 in a child with vulva abnormality as the first manifestation was retrospectively analyzed. Results This was a 29-month-old child, whose social gender was female. The level of her basic luteinizing hormone (LH) was 0.07 mIU/mL, and follicle-stimulating hormone was (FSH) 0.39 mIU/mL. The baseline levels of testosterone (T), dihydrotestosterone (DHT), 17-hydroxyprogesterone (17-OHP) and androstendione (A2) were 0.06 ng/mL, 19.67 pg/mL, 1.20 ng/mL, and 0.07 ng/mL respectively. Those levels were 3.65 ng/mL, 68.25 pg/mL, 51.72 ng/mL, and 14.70 ng/mL respectively after Human chorionic gonadotropin (HCG) stimulation. The levels of her anti-mullerian hormone (AMH) was 22.97 ng/mL, and inhibin B (INH-B) was 274.4 pg/mL. The uterus and ovaries were not detected by Pelvic ultrasound and MRI. The chromosome showed 46, XY. Sex determination (SRY) gene detection showed normal. Androgen receptor (AR) gene detection showed negative. There was pathogenic mutation of 5α-reductase 2 (SRD5A2) gene in peripheral blood of the child and her parents. The penis grows 2 cm after 4 months of treatment with 2.5% DHT gel. Conclusion SRD5A2 is diagnosed mainly based on the increase of T/DHT after HCG stimulation experiment and it can be confirmed by detection of pathogenic SRD5A2 mutation.

BackgroundChoriodal neovascularization is an important ocular manifestation of angiogenesis in eyes,which derives from the choroid capillaries.Recent studies have found that complement activation is playing a key role in the laser-induced CNV.Because of the key position of CFB in the alternative pathway,bytargeting CFB and blocking the alternative pathway may provide an approach to observe the role of this alternative pathway in the generation of CNV.Objective This study was to investigate the inhibitory effect of reconstructed complement factor B (CFB)-small interfering ribonucleicacid(siRNA)on choroidal neovascularization (CNV)and its mechanism. Methods Experimental CNV was induced by laser photocoagulation in 96 eyes of 48 clean Brown Norway rats.The rats were randomly divided into 4 groups.25,50 and 75 μg B factor siRNA were injected via caudal vein on 1 day,3,5 days after photocoagulation in different dose groups,and normal saline solution was injected at the same way in experimental control group.Other 12 normal rats were used as blank control group.Fundus fluorescein angiography(FFA) was performed on 3,7,14,21,28 days after injection of CFB-siRNA and CNV was scored.The expressions of vascular endothelial growth factor(VEGF) and factor Ⅷ in choroid were detected by immunochemistry.The expressions of CFB-siRNA,VEGF,transforming growth factor β2( TGF-β2 )proteins in choroid were determined using immunochemistry in 7,14,21,28 days,and the expressions of mRNA of CFB-siRNA,VEGF,TGF-β2 were examined by reverse transcription polymerase chain reaction(RT-PCR). ResultsFFA revealed that the CNV rates in various doses of CFB-siRNA groups were significant lower than those of experimental control group in various time points(P＜0.05),and those in 75 μg B factor siRNA were decreased in comparison with 25 μg B factor siRNA (P＜0.05).Immunochemistry showed that the intensities of the VEGF and factor Ⅶ expression in various doses of CFB-siRNA groups were weaker than the blank control group ( P ＜ 0.05 ).Compared with the control group,the expression of CFB reduced in 7 days,and then approached to the level near the control group.Fourteen to twenty-one days after injection of CFB-siRNA,VEGF and TGF-β2 depressions in different doses of CFB-siRNA groups were lower than blank control group( P＜0.05 ).CFB expression in choroid showed the lower levels in CFB-siRNA injection group compared with blank control group in from 7 through 21 days (P＜0.05).RT-PCR displayed the gradual increase of CFB mRNA and curve-like changes of VEGF and TGF-β2 with time prolong. Conclusions Recombinated CFB-siRNA can effectively inhibit laser-induced CNV by down-regulating the expression of VEGF and factor Ⅷ.Alternative pathway of complement plays an important role in the production of CNV.

Objective To investigate the changes of non-linear dynamics characteristics of electroencephalogram(EEG) in patients with the stagnation of Liver-Qi syndrome.Methods 15 Liver-Qi stagnation syndrome patients and 15 normal persons were paired by sex and age.The data of EEG under three states(eyes closed,eyes opened,and mental arithmetic with eyes opened) were analyzed by the parameter of point-wise correlation dimension(PD2).Results PD2 of the stagnation of Liver-Qi syndrome group increased significantly compared with that of the healthy control group and always maintain high level.The difference of PD2 between two groups was gradually reduced along with the increase of stimulated condition.Conclusion Non-linear dynamic analysis is more appropriate for the study of mental functions changes of stagnation of Liver-Qi syndrome and can be used to investigate the brain mechanism of the stagnation of Liver-Qi syndrome.

Humans ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis* ; Death, Sudden/etiology*

Animal model is an animal material with human mimic performance established in biomedical scientific research. It can be used as experimental basis for studies of experimental hypothesis and clinical hypothesis. It can shorten the research time and observe the whole process of disease occurrence, development or prevention and treatment. Human biomedical research is largely limited by the biological complexity. In order to overcome this limitation, based on the immunosuppressive characteristics of a severely immunodeficient ( SCID) or recombinant activated gene ( Ragnul ) in mice, humanized mouse models of human diseases can be established and have been widely used to study the underlying principles of human immunobiology and complex pathological mechanisms of human diseases. This approach has become one of the important ways to promote the development of medical sciences, with practicality and foresight. In this paper, the application and research progress of humanized mouse models are reviewed.

This study was purposed to investigate the feasibility to screen donor with HCV infection by means of HCV-cAg ELISA. The first and repeat assays were performed for detection of serum anti-HCV in 8677 donor's serum specimens from January 2003 to December 2005. All serum anti-HCV specimens with positive anti-HCV from first and repeat assays were finally identified by using HCV-cAg ELISA and HCV RT-PCR methods. The results showed that only 5 serum specimens were positive anti-HCV by HCV-cAg ELISA identification in 29 specimens including 15 specimens with positive ant-HCV in first assays and 14 specimens with positive anti-HCV in repeat assays, the positive rate detected by HCV cAg ELISA was 17.24%. 5 serum specimens were positive anti-HCV by HCV RT-PCR detection also in 29 specimens mentioned above, the positive rate detected by HCV RT-PCR was 17.24% too. It is concluded that sensitivity of HCVcAg ELISA is similar to HCV RT-PCR and may be useful for the early diagnosis of hepatitic C or used as a reliable method to screen donor with HCV infection in blood transfusion medicine.
Blood Donors ; Blood Transfusion ; Enzyme-Linked Immunosorbent Assay ; methods ; Hepacivirus ; isolation & purification ; Hepatitis C Antigens ; blood ; Humans ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Viral Core Proteins ; blood