Objective To study the tooth whitening effect of boron-dipyrromethene (BODIPY) as a photosensitive drug combining photodynamic therapy (PDT) and the influence on the surface of the enamel.Methods After oxidation of hydrogen peroxide or BODIPY by photodynamic therapy,the extracted teeth were evaluated by Vita shade guides matching.The change of surface enamel on the crystals and microstructure was observed by scanning electron microscopy (SEM).Results The teeth treated with BODIPY by PDT were smooth and whitened with the remineralization of teeth surface in morphology.While the teeth treated with hydrogen peroxide were whitened obviously but the surface morphology of the teeth was demineralized seriously.Conclusion The results suggest that PDT is effective for teeth whitening and can promote the remineralization of teeth surface enamel with BODIPY as a photosensitive drug.PDT is expected to become a new method for tooth whitening.

Objective To investigate the effect of donepezil hydrochloride on the expression of Calpain Ⅰ-Cdk5/p25 pathway in the hippocampal CA1 area by cerebral ischemia and reperfusion in mice.Methods Mice were divided into model group,sham-operated group and donepezil-treated group.The expression of Calpain Ⅰ in hippocampal CA1 area was measured by immunohistochemistry staining respectively at 4,6 and 8 weeks post cerebral ischemia and reperfusion.Western blot was used to evaluate Cdk5 and p25 protein expression.Results The abilities of learning and memory performance was damaged significantly at 4,6 and 8 weeks after surgery compared to sham-operated group (P＜ 0.05).The expression of Calpain Ⅰ of model group were (0.098 ± 0.009),(0.129 ±0.01),(0.116 ± 0.01),which were higher than that of sham-operated group (0.03 ± 0.003),(0.031 ± 0.003),(0.029 ±0.003) and there was significant difference (P ＜ 0.05).The expression of Cdk5 in model group was (0.54 ± 0.05),(0.73 ± 0.07),(0.7 ± 0.06),which were higher than that of sham-operated group (0.23 ±0.02),(0.31 ± 0.02),(0.33 ± 0.02) and there was significant difference (P ＜ 0.05).The expression of p25 in model group was (0.44 ± 0.04),(0.51 ± 0.04),(0.55 ± 0.06),which were higher than that of sham-operated group(0.19 ± 0.02),(0.24 ± 0.02),(0.2 ± 0.02) and there was significant difference (P ＜ 0.05).The expression of Calpain Ⅰ of donepezil-treated group was (0.041 ± 0.004),(0.054 ± 0.004),(0.046 ± 0.003),which were lower than that of model group.The expression of Cdk5 was (0.28 ± 0.02),(0.33 ± 0.03),(0.38 ± 0.02),and expression of p25 was (0.26 ± 0.02),(0.25 ± 0.03),(0.21 ± 0.02),which were lower than that of model group respectively(P ＜ 0.05).Conclusion Donepezil hydrochloride probably improve the learning and memory abilities by reducing the expression of Calpain Ⅰ and Cdk5/p25.

Objective Nanoparticles are widely investigated and applied in clinical diagnosis and treatment as drug carrier,and their transmembrane process is related to their biological effects.The aim of this study was to investigate the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells via fluorescence tracking.Methods The transmembrane process of nanoparticles was quantitatively analyzed by laser scanning confocal microscopy.Results The analyzing results showed that the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells was strongly temperature-dependent.The receptor-mediated endocytosis mechanism played an important role in the transmembrane process for cellular uptake of nanopaticles.Conclusions This study provides a theoretical basis for design and application of nano-medicines.

BACKGROUND: A new method, i.e., heparin slow-release stent implantation combined with myocardium drilling, is discovered for myocardial revasculadzation, which remarkably improves myocardial perfusion. OBJECTIVE: To investigate the effect of heparin slow-release stent implantation combined with myocardium drilling on myocardial regeneration of pigs with acute myocardial infarction.METHODS: Anterior descending coronary of pig was ligated to induce myocardial infarction model, which was randomly divided into control and implantation groups, with 6 pigs for each group. Self-made borer was used in the implantation group to drill two transmural channels (3.5 mm diameter) on epicardium. A heparin slow-release stent was fixed in the transmural channel. Following intravenous injection, BrdU was used to label DNA duplication so as to observe stromal cell-derived factor-1 (SDF-1) mRNA expression, myocardial perfusion, newborn yocardium, and heart function prior to and following implantation. RESULTS AND CONCLUSION: As compared with control group, SDF-1 expression was enhanced in the implantation group at 6 weeks after stent implantation (P < 0.001), perfusion mass defect percentage was significantly decreased (P < 0.001), ejection fraction of left ventricle was increased (P < 0.05), newborn myocardium was increased (P< 0.001), and survival myocardium in the ischemic region was increased (P < 0.001). The results demonstrated that heparin slow-release stent implantation combined with myocardium drilling could repair damaged myocardial cells and improve heart function through increasing SDF-1 expression and myocardial perfusion.

Objective To evaluate the efficacy and safety of colistimethate sodium (CMS) for the treatment of critical patients infected by pan-drug resistantAcinetobacter baumannii (PDR-AB) or pan-drug resistant Pseudomonas aeruginosa (PDR-PA).Methods 321 isolates of PDR-AB and 204 isolates of PDR-PA from critical patients admitted to 35 intensive care units (ICUs) of grade two or above were collected from the Anhui Antimicrobial Resistance Investigation Net (AHARIN) program from September 2012 to September 2015, while the minimal inhibitory concentrations (MIC) of colistin were determined by the E-test. A series of Monte Carlo simulations was performed for CMS regimens (1 MU q8h, 2 MU q8h, and 3 MU q8h, and MU meant a million of unit), and the probability of achieving a 24-hour area under the drug concentration time curve (AUC24)/MIC ratio > 60 and risk of nephrotoxicity for each dosing regimen was calculated. Each simulation was run over three CLCr ranges: < 60, ≥ 60-90, ≥ 90-120 mL/min. The probability of target attainment (PTA)for the AUC24/MIC ratio was calculated using the partial MIC value, while the cumulative fraction of response (CFR) was determined by integrating each PTA with the MIC distributions, the value greater than or equal to 90% or more than 80% was set as the optimal dosing regimen or suboptimal dosing regimen respectively. The probability of average 24-hour serum concentrations up to 4 mg/L for three dosage regimens was used to predict the risks of nephrotoxicity.Results All 321 isolates of PDR-AB and 204 isolates of PDR-PA were susceptible to colistin, the MIC50/90 against PDR-AB were 0.5mg/L and 1.0 mg/L, and those against PDR-PA were 0.5 mg/L and 1.5 mg/L, respectively. When recommended dose (1 MU q8h) was used for patients with CLCr of < 60 mL/min, high CFR value (89.78% for PDR-AB, 81.06% for PDR-PA) were obtained, but with a high risks of nephrotoxicity (> 32.51%). Moreover, low value of PTA (< 66.56%) was yielded for isolates with MIC of ≥ 1 mg/L. Recommended dose also yielded a low CFR value (56.97%-69.31% for PDR-AB, 44.76%-56.94% for PDR-PA) in patients with CLCr of ≥ 60-120 mL/min. When dose was increased to 2 MU q8h, CFR (77.45%-92.87%) and the risks of nephrotoxicity (< 0.15%) was optimal for patients with CLCr ≥ 60-120 mL/min, but low value of PTA (< 75.36%) was also yielded for isolates with MIC of ≥ 1 mg/L. The most aggressive dose of 3 MU q8h provided high CFR (> 89.24%) even in patients with CLCr ≥ 90-120 mL/min, and PTA was < 76.20% only for isolates with MIC of ≥ 1.5 mg/L, but this dosing scheme was associated with unacceptable risks of nephrotoxicity (> 33.68%).Conclusion Measurement of MIC, individualized CMS therapy and therapeutic drug-level monitoring should be considered to achieve the optimal drug exposure and ensure the safety of CMS.

Objective:To build a three-dimensional evaluation model of single bed efficiency in an obstetrics and gynecology hospital and provide reference for bed management in hospital.Methods:The sample ward and key indicators were determined through interviews. A two-level database was built according to patients′ data from hospital information system. K-means cluster analysis was used to get the beds classified by annual average vacancy(x), annual average turnover(y) and annual average case-mix index per capita(z). The authors built the three-dimensional bed efficiency model with x, y, z as boundaries and analyzed the bed efficiency by comparing the within group average point A k( x k, y k, z k) with the overall average point A0( x, y, z). Whereafter the bed efficiency of each medical work team was analyzed. Results:Thirty-six beds were classified into 4 categories according to utilization efficiency. 50% of the beds(18 beds) were well used, 28%(10 beds) had room for improvement, and 19%(7 beds) may have resource waste. Significant differences existed in bed efficiency among medical work teams.Conclusions:The model in our study can realize in-depth exploration by evaluating bed efficiency from two aspects of the whole ward and each medical work team. This model, which is mainly applicable to the situation where beds are under the charge of fixed medical work groups or doctors, can be adjusted and extended to meet different strategic needs of hospitals.

OBJECTIVE: To establish a fast adaptive active contour model based on local gray difference for parotid duct image segmentation. METHODS: On the basis of the LBF model, we added the mean difference of the local gray scale inside and outside the contour as the energy term of the driving evolution curve, and the local gray-scale variance difference was used to replace and as the control term of the energy parameter value. Two local similarity factors of different neighborhood sizes were introduced to correct the effects of image gray unevenness and boundary blur to improve the segmentation efficiency. RESULTS: During image segmentation, this algorithm allowed for adaptive adjustment of the evolution direction, velocity and the energy weight of the internal and external regions according to the difference of gray mean and variance between the internal and external regions. This algorithm was also capable of detecting the actual boundary in a complex gradient boundary region, thus enabling the evolution curve to approach the target boundary quickly and accurately. CONCLUSIONS The proposed algorithm is superior to the existing segmentation algorithms and allows fast and accurate segmentation of the parotid duct with well-preserved image details.
Algorithms ; Color ; Image Processing, Computer-Assisted ; Parotid Gland ; diagnostic imaging ; Salivary Ducts ; diagnostic imaging