Objective To know the effect of ultraviolet A on energy metabolism in the cells in culture by using the primary cultured postnatal rat cortex neurons for in which there are many mitochondria. Methods The primary cultured postnatal SD rat cortex neurons in 60 mm dishes were exposed to UVA in a chamber in doses of 0, 3, 6 and 9 J/cm2 respectively. The exposure was followed by 4 hours culture and then the activity of cytochrome oxidase (COX) in the single neuron was determined by cytochemisty, the quantitative analysis was done with Image-Pro plus 4.0. Results In every exposure groups, after UVA exposure followed by 4 hours culture, no significant changed vital signs were found under the microscope, the activity of COX in the neurons significantly decreased compared with the control and a dose-response relationship was presented. Conclusion Low level UVA exposure may cause obvious energy metabolism decrease in the cells in culture before the significant changed vital signs are seen.

Objective To investigate the effects of copper and zinc on the activity of cytochrome oxidase(COX)in neurons of rats and go further into the effect on energy metabolism of neurons.Methods After separate culturing of primary neurons and glial cells of the cortex of postnatal rats,neurons were treated with cupric sulphate at0,0.05,0.16,0.5mmol /L,zinc acetate at0,0.05,0.16,0.5mmol /L independently,and copper-zinc3?3pattern.Activi-ty of cytochrome oxidase was assessed with cytochemical method and imaging quantitative analysis.Results When neurons were treated with cupric sulphate at0.16?0.5mmol /L independently,COX activities in experimental groups significantly decreased compared with that in the control group,but there was no significant difference between the other groups treated with cupric sulphate or zinc acetate and the control group.When neurons were treated with copper com-bined with zinc,interaction on activity of COX showed no significance.Conclusion Copper could down-regulate and damage the activity of COX significanty,which was the most crucial energy metabolism enzyme,but combinning expo-sure of copper and zinc did not show significant interaction at the used levels.

Objective To know the mechanism of the adverse effect of formaldehyde on cortex neurons. Methods In the present study, incubation of postnatal Wistar rat cortex neurons in culture with formaldehyde at 1.0, 2.0, 4.0, 8.0 mg/L (medium) was carried out to have knowledge of the effect of formaldehyde on the expressions of GluR2 and GABAR. For keeping the given concentration of formaldehyde, formaldehyde was added to the medium every hour for 4 consecutive hours. Results Immunocytochemistry showed a significant down-regulation of GluR2 and up-regulation of GABAR after 4 consecutive hours of formaldehyde treatment compared with the control (P

Objective To investigate the effect of low intensity microwave electromagnetic fields (EMF) on energy metabolism of cerebral cortical neurons of postnatal rats. Methods The cultured neurons were exposed to low intensity 900 MHz continuous microwave EMF (SAR=0.38-3.22 mW/g) 2 hours a day for 4 to 6 consecutive days. The activity of cytochrome oxidase(CCO) was taken as the index for energy metabolism level. Results The results of cytochemistry showed that compared to the sham-exposed, a significant decrease of cytochrome oxidase activity in exposed neurons(0.38-3.22 mW/g P

Objective To study the effect of benzo(a) pyrene on DNA of human embryonic fibroblast under inhibition of DNA repair,and to explore the mechanism of DNA repair involved in the DNA damage induced by xenobiotic chemical carcinogens. Methods DNA damage of human embryonic lung fibroblast (HELF) induced by benzo(a) pyrene was observed when DNA repair was inhibited by treating HELF with arabinosylcytosin(ara-C) to inhibit the activity of polymerase ?/? in the cells. With S9 mixture added as metabolic activation system in vitro,HELF was treated for 2 hours with ara-C at the doses of 0 and 100 ?mol/L combined with-C at the doses of 0,10,20,50 ?mol/L by the 2?4 factor-factorial analysis.Comet assay was used to assess the DNA damage. Results Compared with the control group,the comet rate and Oliver tail moment of groups treated by B(a)P increased significantly (P

Asthma is a chronic respiratory disease with various etiologic factors.Asthma is believed as a result of interaction between gene variation and environmental factors.Asthma increased rapidly worldwide in recent 40 years, air pollutants are believed to be the important triggers, crossover design and multi-pollutant models were used in the further studies.Although some efforts had been made in the mechanism of asthma triggers, they were limited to the lab studies.Studies in asthma related SNP and its interaction with air pollutants will be a revised method in mechanism researches.Based on epidemiological studies, in vivo and in vitro studies, the biological effects and mechanisms of air pollutants on asthma were discussed and evaluated in this paper.

Stereotactic radiotherapy (SRT), also known as stereotactic ablative radiotherapy (SABR), includes stereotactic radiosurgery and stereotactic body radiotherapy (SBRT). This technique has the characteristics of large single fractional dose, few fractions, high equivalent biological doses, and rapid fall off-target doses. It can be implemented by relatively special equipment such as Gamma knife, Cyberknife, Tomotherapy and Vero 4D RT system, etc. In many cases, SBRT technique is employed based on linear accelerators. SRT differs from conventional radiotherapy in terms of the plan design and plan evaluation. Consequently, it is necessary to discuss the differences and provide guidance for clinical application and research.

Objective To compare the clinical effect of off-pump coronary artery bypass grafting (eft-pump CABG)and on-pump coronary artery bypass grafting(on-pump CABG).Methods The clinical dates of 152 cases with coronary artery bypass grafting(off-pump CABG group 85 cases,on-pump CABG group 67 cases)were received from June 2005 to December 2008,the preoperative dates,postoperative mortality and the rate of complication were compared between two groups.Results The preoperative dates of two groups were no significant difference(P>0.05);2 cases(2.35%)were died in off-pump CABG group and 13 cases(15.29%)had complications in off-pump CABG group;9 cases(13.43%)were died in on-pump CABG group and 25 cases(37.31%)had complications in on-pump CABG group.The mortality and the rate of complication in off-pump CABG group was significantly less than that in on-pump CABG group.it was significant difference(P<0.01).Conclusion Off-pump CABG is safe therapy of mieosurgieal operation.

Objective To evaluate the image quality and registration accuracy of a three?dimensional ( 3D ) dynamic phantom in four?dimensional computed tomography ( 4DCT ) and four?dimensional cone?beam computed tomography ( 4DCBCT) . Methods The Computerized Imaging Reference Systems Dynamic Thorax Phantom Model 008A was scanned to get 4DCT and 4DCBCT images. Two balls with different diameters ( ?= 1 cm and ?= 2 cm) were used to simulate tumors with different sizes. The motion mode of the balls was 3D sinusoidal motion at 0?25 Hz ( the amplitudes along the x, y, and z axes were ±1?0 cm, ±0?4 cm, and ±0?2 cm, respectively). Gross target volumes (GTVs) from 10?phase bins, internal gross target volumes (IGTV), and target volumes on maximum intensity projection (MIP) and mean intensity projection (MeanIP) images were contoured and calculated. Target volumes on 4DCT or 4DCBCT images were compared with the static and dynamic volumes of the balls ( VS and VD ) . The matching index ( MI) of target volumes between the 4DCT and 4DCBCT images was analyzed after rigid image registration. Results The GTV in each phase of the image was larger than VS . The difference between the average GTV derived from 10 phases of 4DCT or 4DCBCT images and Vs of the small ball was larger than that of the large ball ( 35?03% vs. 22?66%;32?62% vs. 17?00%) . All the IGTVs and target volumes on MIP images were slightly larger than VD , but target volumes on MeanIP images were smaller than VD . The average MI of 10?phase bins of the small ball was smaller than that of the large ball ( 66?76% vs. 82?21%) . Moreover, MIs of IGTV,MIP, and MeanIP of the small ball were also smaller than those of the large ball ( 77?39% vs. 90?29%;75?90% vs. 89?28%;74?47% vs. 82?74%) . Conclusions In the case of a relatively small tumor volume and a relatively large motion amplitude, 4DCT and 4DCBCT should be used with caution for comparison of image registration.

Objective To verify the daily delivery accuracy of volumetric-modulated arc therapy (VMAT) and achieve the process quality control (PQC) of linac using statistical process control (SPC)technology.Methods The log files of all treatments were taken out from the linac system.An in-house software which created by Matlab 7.14 was used to analyze the daily parameters accuracy and the mechanism and dose delivery accuracy of the linac for each VMAT,and an daily evaluation report was automatically created for the linac.The stability of the linac and the deviation of the delivery accuracy for various cancer sites were also analyzed.To achieve the process quality control of hnac using SPC technology,the control limit of each parameter was calculated by Johnson alternation and the single value control charts were drawn.Results 76 patients mainly with nasopharyngeal carcinoma,cervical carcinoma,rectal cancer and laryngeal cancer,got the treatment daily with VMAT technology,and a total of 2 446 arcs were delivered by the linac in continuous 16 days.The gantry angle error,y and x collimator position error,MLC leaf position error and dose delivery error were 0.49°,0.09 mm,0.38 mm,0.31 mm,0.05 MU,respectively.Compare to the nasopharynx,uteri,rectal and larynx cancer,it can be seen that the variation factors of dose delivery and gantry angle errors for various cancer sites were higher,which was 8.10％ and 4.54％,respectively.Through the process quality control of the linac,it was found that all the parameters were in control.While some abnormal points arose (the error was greater than UCL),and the ratio of the gantry angle which was out of control (0.45％) was the highest in all parameters.Conclusions linac delivery accuracy could be monitored and verified during the whole VMAT treatment for each patient,and the daily running condition of linac could be monitored.Through the introduction of SPC technology and the control charts,the process quality control of linac in VMAT could be achieved.It is a financial and valid method for the daily quality assurance of linac.