OBJECTIVE:To prepare nifedipine sustained-release hydrogels and to study their drug release in vitro.METHODS:Nifedipine sustained-release hydrogels were prepared by complex coacervation.An orthogonal experiment was performed with chitosan,concentration of sodium alginate,mixing speed and the volume ratio of chitosan solution to sodium alginate solution as factors.Meanwhile,the dissolution rate of the prepared hydrogels was determined by basket-rotating method,and pH-sensitivity of the released drug in different pH medium was investigated.RESULTS:The optimal technical condition was as follows:the concentration of chitosan was 0.4% and that of sodium alginate was 1.5%;the mixing speed was 160 r?min-1;the volume ratio of chitosan solution to sodium alginate solution was 6:1.The dissolution rate of sustained-release hydrogels containing nifedipine was 13.43% in simulated gastric fluid(pH 1.5) at 4 hours,which stood at 52.30% at 4 hours and 81.72% at 12 hours in simulated intestinal fluid(pH 6.8).CONCLUSION:The sustained-release hydrogels of nifedipine showed remarkable sustained-release properties and strong pH sensibility in vitro.

Objective:To determine the fluorine content in enamel before and after besmearing fluoride varnishes or fluorinated bubbles. Methods:Thirty patients whose deciduous central incisors will be extracted were divided into group a and b randomly. For the same patient, a pair of mandibular deciduous central incisor were chosen. For group a: one tooth was removed, and the other one besmeared with fluoride varnishes and removed 24 h later. For group b: one tooth was removed, and the other one besmeared with fluorinated bubbles and removed 24 h later. The fluorine contents in the enamel of every tooth were determined by neutron activation method and analyzed statistically. Results:For group a: the fluorine content in the experimental group was (142.78?42.25) ?g/g, and that in the control group was(119.62?38.62) ?g/g. For group b: (162.36?31.36) ?g/g and (126.56?38.42) ?g/g respectively. The fluorine content in the enamel of tooth besmeared with fluoride varnishes or fluorinated bubbles was higher than that in the control group(P

Objective: To compare the extraction efficiency of imperialine extracted with different solvents. Methods: The content of imperialine in the extracts was determined by thin layer chromatography scanning. Results: Among the methods suitable for alkaloid extraction, the solvent ether chloroform 95% ethanol (25∶8∶2.5) is the best for imperialine extraction. Conclusion: The imperialine extraction efficiency is greatly affected by the extraction solvent.

Objective:To optimize the water extraction process of Lidan Palshi capsules. Methods:The extract yield, emodin con-tent and chrysophanol content were used as the indices, the extraction process of Lidan Palshi capsules was optimized by orthogonal test of L9(34). Results:The optimized water extraction conditions were as follows:adding 14-fold water, and boiling extraction four times with 2 hours for each time. Conclusion:The water extraction process is practicable, reasonable and convenient.

10 mL/min.

Objective To investigate changes of brainstem auditory evoked potential (BAEP)and somatosensory evoked potential (SEP) in patients with acute cerebral infarction,and discuss their relation with prognosis of the patients.Methods The study involved 60 patients with acute cerebral infarction.Changes of BAEP and SEP in each patient were detected and recorded continuously.Prognosis evaluation was performed by using GCS.Another 60 age-matched and gender-matched healthy human beings were enrolled as controls.Results Incubation period of BAEP wave Ⅰ had no significant difference between the cerebral infarction and control groups (P ＞ 0.05).However,interspike intervals of other BAEP waves in cerebral infarction group were different from those in control group (P ＜ 0.05).A series of waves of SEP (P14-N60) were all significantly prolonged in cerebral infarction group (P ＜0.05).Conclusion BAEP and SEP can effectively reflect function of brain stem in patients with acute cerebral infarction and have some values in determining their prognosis.

Objective To separate the side population cells(SP) from breast cancer MCF-7 cell line,and observe its biological characteristics.Methods Flow cytometry and Hcechst 33342 dye efflux assay were used to isolate SP cells and non-SP cells from the MCF-7 cell line of human breast cancer.Tumorigenicity of the two subpopulations was observed by a soft agar cloning method.Results The results of FACS analysis indicated that (6.5 ± 0.4 ) ％of the MCF-7 cells were SP cells;The vitro colony formation rate of SP cells was(38.5 ±9.4)％,and higher than that of non-SP cells ( 8.4 ± 2.6 ) ％ ( t =5.34,P ＜ 0,05 ).Concluslon The SP cells sorted from MCF-7 cell line enriched tunor stem cells,which exhibited high tumorigenicity.It indicated that SP cells should play a principal role in breast cancer.

Nanomedicine is one of the most promising fields in biomedicine. Inorganic nanomaterials stand out among many nanomaterials due to their excellent physicochemical properties, stable chemical properties and high biocompatibility. As an inorganic nanomaterial, bismuth-based nanomaterials have the advantages of adjustable band gap, low toxicity, easy functionalization, large X-ray attenuation coefficient, high photothermal conversion efficiency and long cycle half-life, so they have good promising application in cancer diagnosis and treatment. This review summarizes the recent research progress of bismuth-based nanomaterials in tumor diagnosis, treatment and biosafety, which provides a theoretical basis for the design and exploitation of a new generation of bismuth-based nanomedicine systems.

Objective To investigate the dynamic changes of vascular endothelium secreted factors after oral fatty meal test and the correlation of the factors with blood lipid in elderly diabetic patients. Methods Thirty-six elderly diabetic patients (diabetic group) and twenty heahhy elderly subjects(control group) were selected into the study and received oral fatty meal test for 6 hours. Diabetic group was divided into three subgroups, including fasting hypertriglyceridemia subgroup, postprandial hypertriglyceridemia subgroup and postprandial normotriglyceridemia subgroup. Serum nitric oxide (NO), endothelin-1 (ET-1), plasminogen activator inhibitor-1 (PAl-1) and tissue plasminogen activator (t-PA) were measured before and after oral fatty meal test. Results (1) The level of serum NO was significantly increased and ET-1 was significantly reduced in control group 2 hours after oral fatty meal test and were returned to basal state 6 hours after the test. But in diabetic group, postprandial serum NO level were decreased and ET-1 were increased gradually and reached to the peak 6 hours after oral fatty meal test. The ratio of NO/ET-1 was lower in diabetic group than that in control group (P< 0.01). There were important differences among fasting hypertriglyceridemia subgroup, postprandial hypertriglyceridemia subgroup and postprandial normotriglyeeridemia subgroup(P<0.05 or<0.01). (2) The level of PAl-1 was increased and t-PA was decreased slightly 4 hours after oral fatty meal test in control and diabetic groups. Compared with control group, PAI-1/ t-PA obviously increased in diabetic group. Meanwhile, PAI-1/t-PA in fasting hypertriglyeeridemia and postprandial hypertriglyceridemia subgroups were significantly higher than that in postprandial normotriglyceridemia subgroup(P<0. 05 or<0.01). (3) In the diabetic group, TG was negatively correlated with NO and t-PA(r=-0.360 P<0.05; r=-0.649, P<0.01) and positively correlated with ET-1 and PAI-1(r=0.421,P<0.01;r=0.520,P<0.01). Conclusions The elderly diabetic patients suffer from the imbalance of vascular endothelium secreted factors. The postprandial abnormal TG metabolism may aggravate the change and further damage the vascular endothelial function.

Objective To discuss the combined value of gray-scale ultrasound ( GSUS) and contrast-enhanced ultrasound (CEUS) in the diagnosis of benign and malignant thyroid lesions and to explore the optimal diagnostic point of scoring method .Methods Ultrasound images of 178 thyroid lesions confirmed by pathology were synthetically reviewed by scoring 5 GSUS indicators including shape , orientation, interior echogenicity, halo sign, microcalcification and 6 CEUS indicators including relative arrival time of microbubbles in the periphery and interior, peak periphery and interior echogenicity, peripheral ring-enhancement, and homogeneity of enhancement .One positive indicator scored one point .The optimal diagnostic points and their clinical value were explored according to ROC curves .Results Scores of GSUS, CEUS and the combination of GSUS and CEUS were significantly different (Z =10.188,9.843,10.705,all P <0.001). Areas under ROC curves of GSUS, CEUS and the combination of GSUS and CEUS were 0.936, 0.919 and 0.964, respectively.Three or more positive GSUS indicators of five in a thyroid lesion predicted that the thyroid lesion was malignant , with the sensitivity of 79.6% and the specificity of 91.2%.Two or more positive CEUS indicators of six in a thyroid lesion predicted that the thyroid lesion was malignant , with the sensitivity of 91.8% and the specificity of 81.2%.Five or more positive GSUS and CEUS indicators of eleven in a thyroid lesion predicted that the thyroid lesion was malignant , with the sensitivity of 93.6%and the specificity of 92.3%.The areas under the ROC curve of GSUS and CEUS were 0.936 and 0.919.The area under the ROC curve of the combination of GSUS and CEUS was 0.964, larger than the areas under the GSUS ROC curve and the CEUS ROC curve.Conclusion Ultrasound is valuable in the differential diagnosis of benign and malignant thyroid lesions , and the combination of GSUS and CEUS is the most valuable with 5 points as the optimal diagnostic scoring method .