Humans ; Tracheostomy ; methods

OBJECTIVE:To establish a method for the content determination of Aciclovir cream. METHODS:Centrifugal parti-tion chromatography(CPC)was conducted. The solvent system was hexane-acetonitrile-water(2∶1∶1,V/V/V),the injection vehicle was an aqueous solution of 5%Tween 80 and the volume was 1.0 ml;the flow rate was 5 ml/min;the wavelength was 254 nm. RE-SULTS:There was a good linear relationship between quality concentration and peak area in the range of 0.012 7-0.126 7 mg/ml (r=0.998 7). The RSD of precision,stability and reproducibility tests was all no more than 2.0% and the average recovery was 97.34%(RSD=0.90%,n=9). CONCLUSIONS:The method is with high precision and accuracy,and can be used for the content determination of principal components of Aciclovir cream.

Objective To evaluate the cost-benefit of netting cultivation to block the spread of Oncomelania snails in lake re-gions. Methods The cost-benefit of netting cultivation was investigated by interviewing in the field,the cost of Oncomelania snail survey and control was investigated by retrospective review in Gaoyou Lake regions of Jinhu County from 2009 to 2011. The benefit of netting cultivation to block the spread of snails in lake regions was calculated by the benefit-cost ratio(BCR),and then the cost-benefit of them was calculated. Results The area of netting cultivation in Gaoyou Lake regions was 70.77 hm2,the aver-age cost of netting cultivation was 495 595 yuan every year,the average income was 962 000 yuan every year,and the average ben-efit of netting cultivation was 466 405 yuan. The average cost of Oncomelania snail survey and control from 2009 to 2011 was 85 047.87 yuan in Gaoyou Lake regions. The ratio of cost-benefit was 1.11∶1. The benefit was more than the cost. Conclusion There is a well benefit in lake regions during blocking the spread of snails by netting cultivation.

Objective To evaluate the earlier changes of degeneration discs in vivo using magnetic resonance diffusion tensor imaging (DTI).Methods From September 2010 to March 2011,88 consecutive outpatients [age 16-63 years,mean age (37 ± 13) years] were enrolled in this study.The excluded criteria were as follows: spinal deformity,spinal tumors and post-operation of spine.The mean diffusion (MD) and fractional anisotropy (FA) values on DTI images of 428 intervertebral discs which without susceptibility artifacts were measured.Fiber track (FT) images of annulus of intervertebral discs were analyzed.MD and FA were also measured on FT.The quartile and median were used to record the nonnormal distribution dates.The Chi-square test statistic was applied by SPSS1 1.0 software package.Results Annulus fibrosis type had closely related to the Pfirrmann grading.Three types were divided based on FT charts of degenerated intervertebral disc.Intact type was noted in 135 discs,Pfirrmann Ⅱ level has a high percentage(92 discs,68.15％) in this type; Scrambled type was noted in 195 discs,Pfirrmann Ⅲ and Ⅳ level were accounted for 63.07％ (123 discs) ; Conglomerate type was noted in 98 discs,the Pfirrmann Ⅳ and Ⅴ level were accounted for 83.68％ (82 discs) (Mantel-Haenszel test,x2 =183.90,P ＜ 0.01).Different annulus types had different MD and FA values.The median(range)of FA of complete,messy and clumps type fibrous ring were 0.32 (0.29-4.35),0.35 (0.33-0.38),0.54 (0.46-0.62).The corresponding median(range)of MD were 12.40(11.50-13.20) x 10-10,11.10(9.92-12.00) × 10-10,6.30(5.03-7.72) × 10-10 mm2/s.Scrambled annulus fibers had lower MD values and higher FA values,which had significant difference (x2 =219.74,243.88,P ＜0.01).Conclusions DTI is a non-invasive method to assess intervertebral disc structural changes in vivo.MD and FA values are helpful to evaluate the intervertebral disc degeneration.

The present article introduced the current medical education of the Feinberg School of Medicine in Northwestern University.Thmugh the comparisons on edueation system and carriculums design between United States of America and China,advices were made to the medical education in China.The article shed light on the current reform of medical education in China.

Objective To investigate genotypes and antibiotic resistance of Escherichia coli producing plasmid-mediated AmpC ?-lactamase in Anhui province.Methods A total of 407 clinical isolates of nonrepeated Escherichia coli were collected from different cities in Anhui province.AmpC ?-lactamase producing isolates were identified by cefoxitin three-dimensional test and antibiotic susceptibility was identified by agar dilution test.Plasmid extraction,PCR amplication of corresponding group was performed, followed by sequencing.Results The positive rate of cefoxitin three-dimensional test was 8.1% (33/407), and the prevalence of plasmid-mediated AmpC ?-lactamase was 3.0% (12/407).bla_(CMY-2) gene,bla_(DHA-1) gene and bla_(ACT-2) gene were identified by PCR amplification and confirmed by sequencing in 5 strains,4 strains and 2 strains,respectively.A new CMY genotype was identified,with its sequence revealed 97% identity to the deduced amino acid sequence with previous CMY-2.This is also the first report on ACT-2 genotype in China.The susceptibility test showed that all strains were resistant to cephamycins and piperacillin,and susceptible to imipenem.Two strains of Escherichia coli producing DHA-1 were resistant to fourth-generation cephalosporin.Conclusions CMY-2,DHA-1 and ACT-2 are the most common genotypes in plasmid-mediated AmpC ?-lactamase produced by clinical Escherichia coli isolates in Anhui province. Carbapenems could be the first choice for the treatment of infection caused by AmpC ?-lactamase producers.

Objective To investigate the correlation of the vascular endothelial growth factor (VEGF) gene variations in the promoter region with the sporadic Alzheimer' s disease (SAD) in Chinese Han population for better understanding the mechanism of SAD. MethodsThe polymorphisms of 279 SAD Chinese Han patients from Northern China were analyzed by comparing with those from 317 healthy individuals using the method of polymeraee chain reaction-restriction fragment length polymorphism ( PCR-RFLP) or direct sequencing.The commercial statistics package SPSS 11.5 was used to compare the distribution of the allele and the genotype, and to analyze their correlations with SAD. ResultsThree polymorphism sites were found for the VEGF promoters in the Chinese Han sample group including -2578C/A,- 2549I/D and- 1154G/A.- 2549I/D and- 2578C/A exhibiting strong linkage disequilibrium. Individuals with the A allele at position -2578 had an insertion of 18 nucleotides at -2459I/D, whereas CC homozygotes did not contain th es were found between the SAD patients and the controls in the 3 VEGF polymorphisms. After adjusting the data for gender, age and the ApoE ε4 allele using Logistic regression, the - 1154G/G genotype of the VEGF promoter might increase the risk of SAD in Chinese Han population.Among the subgroup without the ApoE ε4 allele, -2549D/-1154G haplotype might increase the risk for SAD (OR = 1.325, 95％ CI 1.023--1.716, P=0.033). ConclusionsThree polymorphism sites ( -2578C/A, -254911D, and -1154G/A) are found in the VEGF promoter regions in Chinese Han population. The-1154G/G genotype of the VEGF promote appears to increase the risk of SAD in Chinese Han population.In the absence of ApoE ε4, the -2549D/-1154G haplotype of the VEGF promoter appears to affect the risk for SAD.

Objective To investigate the effects of airway pressure release ventilation (APRV) in children with severe pneumonia-related acute respiratory distress syndrome(ARDS).Methods Ten children suffering severe pneumonia-related ARDS with APRV were included in Pediatric Intensive Care Unit, Beijing Children's Hospital,Capital Medical University from March 2011 to October 2014.Ventilation variables, changes of airway pressure and Ramsay scores were collected and compared with that in conventional ventilation (CV).Clinical variables were measured at CV before APRV and at 1,4,12,24 hours after transition to APRV.Results High airway pressure(Phigh) at each time point during APRV was significantly lower than peak airway pressure (Ppeak) or plateau airway pressure (Pplat) in CV[(26.00 ±2.94) cmH2O(1 cmH2O =0.098 kPa) ,(24.40 ±3.34) cmH2O,(23.30 ±3.46) cmH2O,(23.00 ± 3.80) cmH2O vs (31.80 ± 5.59) cmH2O, P ＜ 0.01].Mean airway pressure (Pmean) at each time point during APRV was significantly higher than that in CV [(23.00 ± 2.86) cmH2 O, (21.69 ± 3.12) cmH2 O, (20.89 ± 3.31) cmH2 O, (20.46 ± 3.48) cmH2 O vs (17.50 ± 2.37) cmH2 O, P ＜ 0.05].Fraction of inspired oxygen (FiO2) were significantly decreased at 4, 12 and 24 hours after APRV than that in CV [(73.00 ± 22.39) ％, (63.50 ± 20.16) ％, (63.00 ± 21.11) ％ vs (88.00 ± 15.49) ％, P ＜ 0.05].Ramsay scores were significantly decreased at each time point during after APRV than that in CV [(3.90 ± 0.74) scores, (2.90 ± 0.88) scores, (3.00 ± 1.15) scores,(3.50 ± 0.71) scores vs (4.60 ± 0.52) scores, P ＜ 0.05].Conclusions Compared with CV, APRV had a lower Phigh and FiO2 ,a higher Pmean and more shallow sedation.APRV may be an effective ventilation mode in children's severe pneumonia-related ARDS.

Objective To observe the hindpaw withdrawal threshold (HWT), and the ultrastructure and expression of glia cell line-de-rived neurotrophic factor (GDNF) in sciatic nerve (SN) in chronic constriction injury (CCI) rats after pulsed radiofrequency (PRF). Meth-ods 30 Sprague-Dawley rats were divided into sham modeling-sham treating (SS) group, CCI-Sham treating (CS) group and CCI-PRF (CP) group. The right SNs of the rats in the CS and CP groups were ligated, and it was separated without ligation in the SS group. The CP group accepted PRF at the ligation 14 days after modeling, while the electrodes were placed without electricity in the SS and CS groups. Their HWT was measured before and 1, 7, 14 days after modeling, and 1, 7, 14 days after treatment. The right SN of ligation was observed under electron microscope 14 days after treatment, meanwhile, the GDNF expression was determined with enzyme-linked immunosorbent assay (ELISA). Results HWT was significantly shorter in the CS and CP groups than in the SS group after modeling, and it increased in the CP group 14 days after treatment compared with that of the CS group (P<0.01). The degeneration of SN significantly improved in the CP group compared with the CS group, while the expression of GDNF increased compared with that in the CS and SS groups (P<0.01). Conclusion PRF could relieve the CCI-induced neuropathic pain by upregulating the GDNF expression in the SN to prevent the SN from injury.

BACKGROUND: Root canal files fracture is a kind of common oral clinical complications. Therefore, it is of clinical importance to study the cyclic fatigue of different types of stainless steel root canal files.OBJECTIVE: To explore the effect of the bending angle and cross-sectional area of root canal instruments on cyclic fatigue of stainless steel files.METHODS: Thirty 25# stainless steel K files (25 mm in length) were selected, the same to 30# and 35#. And these three kinds of files were respectively randomized into three groups (n=10 per subgroup). In the nine subgroups, the files were placed into self-made root canals at the bending angle of 45°, 60°, 90°, and driven by a 16:1 reducer (350 r/min).Fracture time in each subgroup was recorded and converted into the number of rotations. The microstructure of the fracture end of the files was observed under scanning electron microscope. Fractured files were collected and the crack tip length was measured by an electronic caliper.RESULTS AND CONCLUSION: At the same bending angle, the number of rotations resulting in file fracture was significantly reduced with the increasing of the cross-sectional area of the files (P < 0.05). When the type and cross-sectional area were same, the number of rotations resulting in file fracture was significantly reduced with the increasing of the bending angle of the root canals (P < 0.05), indicating a reduction in the cyclic fatigue performance of the files. Toughness fracture occurred in all the files, and circular or oval roughness nests with different sizes and microcavities formed on the fracture surface. In addition, brittle surfaces could be detective between the roughness nests. The diameter of roughness nests was gradually increased with the increasing of the bending angle of the root canals. For 30# and 35# files, the number of brittle surfaces was gradually increased with the increasing of the bending angle of the root canals. For 25# files, the crack tip length was gradually decreased with the increasing of the bending angle of the root canals, but there was no significant difference (P > 0.05). For 30# and 35# files, the crack tip length was significantly shortened with the increasing of the bending angle of the root canals (P < 0.05). But there were no significant changes in the 35#-60° and 35#-90° groups (P=0.095). At the same bending angle, there were no regular changes in the crack tip length in the different types of files. In conclusion, with the increasing of the cross-sectional area, the cyclic fatigue performance of the files with the same length and taper is reduced and the files become easy to be fractured; with the increasing of the bending angle of the root canals, the files with the same types are apt to be fractured near the root tip, indicating the shorter length of the crack tip indicates the more difficulty in the removal of the broken files.