Objective To study the effect of restraint and watered stress of different durations on the gastric empting in rats. Methods 48 male SD rats (weight ±150 g) were divided randomly into 6 groups with 8 in each. The experimental rats were restrained and watered in 23℃ water box for 1 h/d, while the controls were free. The body weight, general conditions and behavioral indexes of the rats were observed and recorded. The gastric empting rate was measured in rats with semi-solid diet after 3 d,7 d and 28 d during the statistically significant differences among different groups of different stress groups,and between the 3 d test group and 3 d control group. The gastric empting rate was higer in the 7-day test than in 7 d controlled group, lower in the 28 d test group than 28 d control group. Conclusion Different chronic stress can cause changes of gastric empting rate. With the prolonging of stress time, the empting rate is rising and then decending.

Objective To analyse CT findings of pleural mensothelioma caused by crocodolite in their living environment.Methods CT findings of malignant pleural mensothelioma in 55 cases were reviewed and analyzed retrospectively.Results Of 55 cases there were localized pleural mensothelioma in 1 accompanied with less pleural effusion and malignant diffuse pleural mensothelioma in 54 ,of which 13 cases had no pleural effusion,30 cases had less or more effusion and 11 cases had a large amount of pleural effusion.In 4 cases,mensotheliomas localized in low-right thorax accompanied pleural effusion in left thorax.The CT findings of these four patients were pleural thickening more than 2 cm.The lesion was manifested as decorative border,nodule and mass of soft tissue and there was much enhancement.Conclusion CT scan is very helpful in detecting the location,extent of pleural mensothelioma and follow-up of patients.

The stability of cell genetic material is influenced by a variety of factors, both internal and external, which can cause various types of DNA damage, such as DNA alkylation, oxidation, mismatching, loop structure, atypical DNA structure, single-strand break, and double-strand break.These DNA damages disrupt cellular homeostasis and dynamic equilibrium, which cause gene mutations, chromosomal abnormalities, and even degradation, aging, and death at different biological levels.By searching and identifying DNA damage sites, the cell activates a series of biochemical pathways, coordinates the progress of DNA replication and transcription, and then repairs the DNA damage.In this way, the cell maintains its independence and stability.While radiotherapy plays a role in eliminating tumors by DNA damages, it also initiates DNA damage responses.Among the responses, base excision repair, nucleotide excision repair, mismatch repair, double-strand break repair, and post-translesion synthesis repair play a key role in repairing the damages.The dysfunction of these repair pathways will cause differences in tumor radiation sensitivity.This paper summarizes recent research results in DNA damage repair, and focuses on the types of DNA damage and their repair mechanisms, so as to promote the understanding of the great significance of this field and to provide a theoretical basis for exploring the application of DNA damage repair pathways in tumor therapy.

Objective To explore CT features and clues to diagnosis of rhabdmyosarcoma(RMS) in head and neck .Methods 14 cases of rhabdmyosarcoma scanned by CT were co llected retrospectively during 1992～2001 and comparatively studied by the age o f patients and the pathologic types. Results Children and adolecence were mainly involved in R MS in head and neck which pathologic types were embryonal type and adeno-vesicle type ,and the former was the main type .CT features of rhabdomyosarcoma include d round and oval masses which had a homogeneous high density and close relation to muscles ,obvious enhancement after injection of contrast media ,often complic ated with the wide destruction of bone and other adjacent tissues,the collecting lymph node enlargment.Conclusion CT findings of rhabdomyosarcoma in head and ne ck had some features and combined with the age of patients can be made the diagn osis of RMS.

The pharmacokinetics of ibuprofen enantiomers were studied in rats after intravenous and oral administration of ibuprofen arginate by means of a chiral HPLC method. The pharmacokinetics of ibuprofen was stereoselective after intravenous and oral administration of ibuprofen arginate. The pharmacokinetic stereoselectivity was higher after oral administration than that after intravenous administration. The systematic (R)-(-)-to-(S)-(+) inversion might be more important than the presystematic one in the stereoselective pharmacokinetics after oral administration. Oral administration of ibuprofen arginate resulted in a very rapid absorption of (S)-(+)-ibuprofen (eutomer), and the absolute bioavailabilities of (S)-(+)-ibuprofen and (R)-(-)-ibuprofen were about 100% and 80%, respectively. Based on the systemic exposure of (S)-(+)-ibuprofen, it could be concluded that the pharmacological actions might be similar when ibuprofen arginate was given orally and intravenously, except some differences in the onset of action.

Objective To evaluate the alteration of CD4+ regulatory T cells in peripheral blood from patients with ankylosing spondylitis(AS). Methods Seventy-eight AS patients and 50 healthy individuals were included in this study. The proportion of CD4+CD25+CD127lo/- T cell population in CD4+ T cells as well as that cytotoxic T lymphocytes(CTL) and NK cells in lymphocytes was evaluated by flow cytometry. Serum TGF-β and TNF-α were measured by ELISA. The inhibitory function of CD4+CD25+ regulatory T cells was measured by mixed lymphocyte culture. Results The population of CD4+CD25+CD127lo/- T cells in peripheral blood of AS patients accounted for (4.36±1.21)% of CD4+ T lymphocytes, which was significantly lower than that in healthy individuals (P<0.05). The CD4+CD25+CD127lo/- T cells population in AS patients was positively correlated with TGF-β level, but negatively with TNF-α. Compared with healthy individuals, the function of CD4+CD25+ regulatory T cells in the inhibition of alloreactive T cells was lower in AS patients, which was related to the decreased secretion of TGF-β. Conclusion The CD4+ regulatory T cells in peripheral blood of AS patients are significantly decreased and its function is defective, which leads to immune regulatory dysfunction in vivo. It may be one of immune pathogenesis mechanisms of AS.

Objective To compare the results of three dose verification solutions of esophageal carcinoma IMRT plans. Methods Seven esophageal carcinoma cases were planned with Pinnacle 8.0 h.The MATRIXX and Delta4 were chosen as the two-dimensional dosimetry and three-dimensional dosimetry.IMRT plans and Delta4 phantom plans were also recalculated by Monte Carlo. Gamma values were evaluated for MATRIXX and Delta4 with 3 mm/3% gamma criteria. For the comparison of Pinnacle, Delta4 and Monte gamma maps, the dose distribution in central plane, dose profiles and dose-volume histograms were used to evaluate the agreement. Results The gamma maps comparison show that with 3 mm/3% gamma criteria an over 98% pass ratio was obtained by MATRIXX measurement. A 94. 4% gamma pass ratio whicl.contains 4 fields gamma pass ratio lower than 90%, was obtained by Delta4 measurement. A 97.6% and 99. 8% gamma pass ratio was obtained between the Delta4 measurement and Monte Carlo simulation with 2 mm/2% and 3 mm/3% gamma criteria. The dose distribution in central plane and dose profiles from Pinnacle calculation were almost in agreement with both the Monte Carlo simulation and Delta4 measurement. The DVH plot have slightly differences between Pinnacle and Delta4 measurement as well as Pinnacle and Monte Carlo simulation, but have excellent agreement between Delta4 measurement and Monte Carlo simulation. Conclusions It was shown that all the three methods can be used very efficiently to verify esophageal carcinoma IMRT delivery, Delta4 and Monte Carlo simulation no data missed. The primary advantage of Delta4 is the fact it can measure true 3D dosimetry while Monte Carlo can simulate in patients CT images but not in phantom.

Objective To investigate the value of dual‐energy CT iodine image morphology and iodine concentration in thyroid cancer diagnosis .Methods The patients underwent dual‐energy contrast scanning and confirmed with pathology results were en‐rolled .90 cases (60 malignant nodules and 30 benign nodules) were chosen with the CT value of internal carotid :110-250 HU at ar‐terial phase and 70-110 HU at venous phase .The iodine concentration of normal thyroid and neoplasms were measured respective‐ly ,as well as the NICnod (normalized iodine concentration) .Then the data was compared among each groups .The iodine image mor‐phology was also analyzed of each neoplasms ,and sensitivity ,specificity and accuracy were calculated .Results ①In the iodine image the characteristics of thyroid cancer ,including irregular shape ,invading neighbor structure and uncompleted enhanced ring around the tumor ,have significant differences compared with normal CT image (P all<0 .05) .Between iodine image and normal image ,the dis‐crete granular calcification has no difference (P>0 .05) .②There were significant differences in the venous phase NICnod value from normal groups ,malignant groups and benign groups (P<0 .05) .When diagnosed as malignant tumor ,the critical NICnod was under 0 .76 ,the area under the ROC curve of AUC value were 0 .91 ,the sensitivity and specificity were 74 .61% and 75 .60% ,respectively .③The sensitivity ,specificity and accuracy of iodine image combined with the NICnod to diagnose thyroid cancer were 91 .67% ,86 .67% , 94 .44% ,respectively .Conclusion Dual‐energy CT iodine image morphology and iodine concentration have important value in thyroid cancer diagnosis .

The aim of laboratory evaluation of basic education is to improve the quality of experimental teaching,which demands thorough reforms of many aspects,including the ranks of teachers,administration,content,methods and instrument of teaching. This article summarizes the experience and achievement of Functional Laboratory Centre,Central South University during under- graduate teaching evaluation by the Ministry of Education in 2006.

Objective To explore the value of intelligent optimum tube voltage technology at dual-source CT coronary angiography.Methods One hundred and fifty patients with normal body mass index (＜25 kg/m2) with clinically suspected coronary heart disease requiring coronary artery CTA examination were collected.According to the different scanning method,patients were randomly divided into 5 groups,30 cases of each group were tested by coronary artery CTA examination.The intelligent optimum tube vohage scanning technology was set to Semi,the tube voltage of A,B,C group were 120,100 and 80 kV (Ref 120 kV,400 mAs),respectively.D and E group were set to on,the reference voltage of group D was 120 kV,and reference current was 400 mAs.The reference voltage of group E was 100 kV,reference current was 400 mAs.Using the 15 section improved segment method for evaluation of coronary artery (lumen diameter＞ 2 mm and no severe calcification).They were assessed by subjective evaluation (image quality score) and objective evaluation (including vascular CT value,signal-to-noise ratio and contrast to noise ratio).Analyses of the differences between groups were compared with image quality,objective evaluation index and radiation dose by single factor variance.Results The image quality scores in patients scanned with five groups were (3.42±0.63),(3.41±0.54),(3.49±0.33),(3.45±0.43) and (3.48±0.81),there was no statistical difference between the five groups (F=0.634,P=0.105).Each image quality was good,all could clearly show thewhole range of vessels.The CT values of the coronary artery with above groups respectively were (486±82),(554±71),(742±90),(506±81),(561±81) HU.The image noises were (25±12),(32±12),(46±14),(28± 11),(34±12) HU (F=3.430 and 4.332,P＜0.05).And the SNR and CNR was no statistic difference between the five groups (P＞0.05).The effective radiation dose of five groups are (9.3± 1.3),(6.3± 1.4),(2.8±1.5),(5.7 ± 1.2),(3.9 ± 1.3) mSv,which the difference was statistically significant (F=2.332,P＜0.05).Conclusions Intelligent optimum tube voltage technology (Ref.100 kV,400 mAs) at dual-source CT coronary angiography may be feasible in patients with normal BMI.To ensure the quality of the image at the same time,it can effectively reduce the radiation dose.