Tumors are classified into two major categories,benign and malignant.One main difference between malignant and benign tumors is their tendency to metastasize and recur.The metastasis itself is an ominous sign for prognosis and responsible for most cancer deaths.The metastatic "cascade" comprises a lot of steps,including escape from the primary tumor site,penetration of local stroma,entry of local vascular or lymphatic vessels,aggregation with platelets,interaction with and adhesion to distant endothelia,extravasation,recolonization,and expansion,all the time avoiding effective immune clearance and being able to survive.It has now been shown to contain stem cell-like cells called cancer stem cells(CSC) in several solid tumors.Although generally rare,these cells appear to be highly tumorigenic and may drive tumor formation and mediate tumor metastasis.

Angiogenesis is an important feature of malignant neoplasm and plays an essential role in the genesis,growth and metastasis of tumors. CT perfusion imaging (CTPI),as one of the functional imaging techniques reflecting neovascularity of neoplasm,perfectly combines anatomical imaging with physiological information and can be used in a range of clinical areas,such as differentiation between benign and malignant lesions,early detection of malignancy or metastasis,prediction of tumor behavior and the assessment of responses to therapies. Many researches have been done on perfusion CT in tumors of the brain,thyroid gland,salivary gland,mammary gland,lungs,liver,esophagus,kidney,colorectum,and so on. The present article reviews the basic principles of perfusion CT and its clinical application in tumors.

Objective To investigate the efficacy of anesthesia with propofol-remifentanil given by targetcontrolled infusion (TCI) for thymectomy in patients with myasthenia gravis ( MG). Methods Forty-five ASA Ⅰ or Ⅱ MG patients aged 16-64 yr weighing 45-95 kg undergoing thymectomy were studied. Anesthesia was induced with TCI of propofol (target plasma concentration 4 μg/ml) and remifentanil (target effect-site concentration 4 ng/ml). Thracheal intubation was performed after topical anesthesia with 2% lidocaine 2-3 ml and then the patients were mechanically ventilated. Anesthesia was maintained with TCI of propofol ( target plasma concentration 3-5 μg/ml) and remifentail (target effect-site concentration 3-6 ng/ml). Sufentanil 0.15 μg/kg was injected intravenously for analgesia 30 min before operation. The success rate of intubationat at first attempt, body movement in response to skin incision, recovery time, extubation time, extubation condition at the end of operation and cardiovascular events were recorded. Results Thracheal intubation was performed successfully in all patients. The success rate of intubation at first attempt was 100%. No body movement occurred during skin incision in the patients.Recovery time was 1.0-3.2 min and extubation time 2.6-7.0 min. All patients were successfully extubated at the end of operation. Bradycardia developed in 3 patients and hypotension in 4 patients during induction, but they all returned to normal after symptomatic treatment. Bradycardia developed in 3 patients during operation, but returned to normal after symptomatic treatment. Conclusion Anesthesia with TCI of propofol and remifentanil can be used safely and effectively in MG patients undergoing thymectomy.

Objective To compare the EC50 ～ EC95 for propofol and remifentanil targetcontrolled infusion(TCI)at loss of consciousness (LOC) and without response to a standard Hoxious painful stimulus in elderly and young adult patients.Methods A total of 102 (American society of anesthesiologists) ASA Ⅰ-Ⅱ patients undergoing elective surgery under general anesthesia were enrolled in this study and divided into control group (aged 18-64 years,n=52) and elderly group (aged≥65 yrs,n=52).Propofol TCI was started at target plasma concentration (Cp) of 1.2 mg/L and the Cp increased by 0.3 mg/L every 30s until loss of consciousness (LOC),kept the target effectsite concentration (Ce) of propofol at LOC.Remifentani TCI was started at Cp of 2.0 μg/L,increased by 0.3 μg/Levery 30s until loss of somatic response to a tetanic stimulus (50Hz,80mA,0.25ms,4s) Cp,Ce,systolic blood pressure (SBP),diastolic blood pressure (DBP),mean artery pressure (MAP) and heart rate(HR) were recorded.The Ce of propofol at LOC,the Ce of remifentanil at loss of somatic response to noxious stimulus in 50％-95％ of the patients (EC50-EC95),and 95％ confidence interval were determined by probit method.The adjustment required for TCI propofol with remifentanil in elderly patients was explored.Results In elderly group,the propofol Ce at LOC was (2.0±0.3) mg/L,significantly lower than that in control group (2.9±0.2) mg/L (t=6.168,P＜0.01) and EC50-EC95 of remifentanil at loss of somatic response to noxious stimulus in elderly group (3.5-5.4) μg/L was similar to that in control group (3.7-5.9) μg/L.Conclusions For TCI propofol and remifentanil in elderly patients,the requirement of Ce of propofol is significantly decreased and Ce of remifentanil required in elderly patients is similar to adult patients.

There are a large amount of neural stem cells in the olfactory system which have an active proliferation, ongoing and direc-tional differentiation and migration in order to adapt to the changing environment. The clinical findings showed that the early stages of some neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease all presented dysosmia. In recent years, the relationship be-tween air pollution and dysosmia attracts public concerns. This article introduced some research progresses in this field.

Objective To compare the effect of electroacupuncture at head points and body points on glucose metabolism of the cerebral motor function regions in normal subjects.Methods To observe the change of glucose metabolism of cerebral motor area in normal subjects between before and after acupuncture during the movement by PET.Talairach coordinates(Atlas of brain) and statistical parametric mapping(SPM) software were used to deal with the acquired imaging data.Results ① Acupuncture at Baihui(GV20) and left Qubin(GB7) could increase metabolism of glucose in bilateral Lps and precuneus,the activation of left area in the brain being more significant.②Acupuncture at right Quchi(LI11) and Zusanli(ST36) change metabolism of glucose in left gyrus precentralis,right loblus paracentralis,right gyrus frontalis medialis,both cerebellums and both putarnens.Conclusion All acupoints can change glucose metabolism in cerebral structures related to motor function in the bilateral cerebral hemispheres,different acupoints active different motor areas.The function of acupuncture is a kind of comprehensive regulative process.

Objective To observe 125I seed treatment effect and environmental radiation in the treatment of recurrent glioma.Methods 64 patients with recurrent glioma patients,according to the wishes of patients and their families were divided into observation group of 30 cases and a control group of 34 patients.Clinical outcomes and follow-up of 125I seeds around radiation were compared between the two groups.Results The treatment efficiency of observation group and control group was 60.0％ (18/30),and 35.3％ (12/34),respectively,which was statistically significant(x2 =8.39,P ＜0.05).Follow-up from 0 to 6 months,the ambient radiation rapidly decreased as the distance increaseing with the implantation point,radiation dose in a distance of 40cm has been close to the natural basis of radiation dose;125I seeds measured radiation dose continued to decay with increasing time after implantation.Four months later,it was close to the natural basis of radiation dose.Conclusion Conclusion 125I radioactive particles in the treatment of recurrent glioma have good curative effect.The effects of radiation on the surrounding environment crowd are easily protected.

Objective To investigate if the endothelin-1 (ET-1),nitric oxide(NO) can affect renal artery blood flow and explore the clinical value of ultrasonography in hypertensive disorder complication pregnancy.Methods 18 patients of gestational hypertension,18 patients of gently preeclampsia,20 patients of severe preeclampsia and 20 normal pregnancy women were chosen in random.Color Doppler ultrasonography was used to detect the peak systolic velocity (PSV),end diastolic velocity (EDV),resistive index (RI),pulsatility index (PI) of renal interlobar artery.The levels of serum ET-1 and NO were measured by enzyme-linked immunosorbent assay (ELISA) and nitric acid recovery respectively.Results The level of EDV in preeclampsia patients were significant lower than the control group (P ＜0.05).The levels of RI,PI,S/D in preeclampsia patients were significant higher than the control group (P ＜0.05).The level of ET-1 in study group was higher than control group (P ＜0.01).The level of NO in study group was lower than control group (P ＜0.01).There was positive correlation between the RI,PI,S/D of renal interlobar artery and the level of serum ET-1.There was inverse correlation between the RI,PI,S/D of renal interlobar artery and the level of serum NO.Conclusions Endothelial dysfunction can cause unbalance of renal vessel systolic-diastolic function.The level of renal artery blood flow parameters can reflect the state of vessel function and have clinical value in hypertensive disorder complication pregnancy.

Objective To investigate the imaging diagnostic value of the early avascular necrosis of the femoral head(ANFH) in adult.Methods There were 25 cases (34 hips) with early ANFH diagnosed by imaging and clinical data.Radiography,CT and MRI findings of ANFH were analysed comparatively.Results In the 34 ANFH included stage Ⅰ 13 hips,stage Ⅱ 21 hips.The diagnostic accurary was 32.4% for X-ray,61.8% for CT and 100% for MRI.Conclusion MRI is better than the other technique in early finding the lesions of ANFH,and the diagnostic sensitivity and accuracy of MRI are higher than that of CT and X-ray.

Objective To construct eukaryotic expression vector of antisense MBD1 gene fragment and to provide a tool for studying MBD1 gene function. Methods PCR primers were designed according to the coding sequence of MBD1 gene. Xba I and Kpn I recognition sequences and cutting sites were added to the 5' end of the sense and antisense primer respectively. The 342 bp specific PCR fragment was obtained from the cDNA of biliary tract carcinoma cell line QBC-939 using RT-PCR, the purified PCR fragment was then inserted reversely into the multiple cloning site of eukaryotic expression vector pcDNA3. 1 ( + ). The constructed recombinant plasmid was identified by PCR confirmation, Xba I and Kpn I double enzyme digestion and DNA sequencing. Results The 322 bp specific DNA band was obtained by PCR, Xba I and Kpn I double digestion produced a 327 bp and a 5. 4 kb DNA band which represent the inserted target gene fragment and the vector respectively. The sequencing result confirmed that the sequence of inserted fragment was correct. Conclusion The eukaryotic expression vector of antisense MBD1 gene fragment was constructed successfully by using gene cloning technique. It will be a useful tool for studying MBD1 gene function in DNA methylation and tumorigenesis.