BACKGROUND:The existed femoral head necrosis(FHN)model can not reflex the clinical necrosis of femoral head correctly.Microwave heating provides a new approach for model preparation.but the concrete standard remains uncertain.OBJECTIVE:To study the optimal temperature and time jn preparing a FHN model induced by microwave heating.METHODS:Totally 48 rabbits were randomly divided into 4 groups on the basis of the microwave temperature(50,55,60℃)and heating time(10,20 minutes).The microwave antenne was inserted into the rabbit femoral head.The rabbits were sacrificed immediately and at 1,2,4,8 and 1 2 weeks after operation.A series of examinations were performed including gross observation,X-ray.histology and MRI to observe the femoral head necrosis and repair status.RESULTS AND CONCLUSION:Marrow partially solidified in the group(50℃,10 minutes)at 1 week,and the osteonecrosis returned to normaI at 8 weeks after operation.1n the group(55℃,10 minutes),marrow was completely coagulated at 1 week and low signal on T1 weighted images and increased signal on T2 images were identified at 2 weeks.Osteonecrosis and repair occurred at the same time at 4 weeks.At 12 weeks,the osteonecrosis continued and the repair stopped,and the femorel heads started to collapse.All femoral heads collapsed at 8 weeks in group(50℃,20 minutes)and group(60℃,10 minutes).Accordingly.microwave heating is a good method in developing FHN model.55℃ and 10 minutes are the optimal temperature and time for the development of FHN model of rabbits induced by microwave heating.

BACKGROUND: An ideal model of osteonecrosis of the femoral head is beneficial to the study on the cause of disease, pathogenesy and treatment. So far there has not been a coherent method to prepare this model. OBJECTIVE: To establish a rabbit model of osteonecrosis of femoral head induced by microwave heating, and to decide optimum microwave temperature and heating time.DESIGN: Randomized controlled animal trial.SETTING: Animal Experimental Center of Kunming Medical College.MATERIALS: The experiment was performed at the Animal Experimental Center of Kunming Medical College between September 2004 and November 2005. Forty-eight healthy adult New Zealand rabbits, either male or female, were provided by the Animal Experimental Center of Kunming Medical College. The animal procedure was accorded with the ethical standards. GW-92C multi-functional microwave therapy apparatus was the product of Grand World Medical Apparatus (Tianjin) Co., Ltd. METHODS: The microwave antenna was inserted into the rabbit femoral head. Ninety-six femoral heads in forty-eight rabbits were randomly divided into four groups (n =24) according to the microwave temperature and heating time: microwave heating at 50 ℃ for 10 minutes group; 55 ℃ for 10 minutes group; 50 ℃ for 20 minutes group and 60 ℃ for 10 minutes group. The models of osteonecrosis of femoral head were induced by microwave heating using multi-functional microwave therapy apparatus according to the temperature and heating time of grouping. MAIN OUTCOME MEASURES: In each group, two rabbits (four femoral heads) were killed immediately, one, two, four, eight and twelve weeks after operation, respectively. A series of examinations were carried out, including gross observation, X-ray to observe bone trabecular arrangement, cystis degeneration, head collapse or hip joint destruction, MRI to observe the necrotic area, and HE staining to observe the osteonecrosis and bone repair. RESULTS: Marrow tissues partially coagulated in the microwave heating at 50 ℃ for 10 minutes group at the end of the 1st week, and the osteonecrosis returned to normality at the end of the 8th week. In 55 ℃ for 10 minutes group, marrow tissues were completely coagulated at the end of the 1st week, and decreased signal on T1 weighted images and increased signal on T2 images were identified at the end of the 2nd week. In the 4th week, bone repair was found simultaneously when osteonecrosis occurred. At the end of the 12th week, the osteonecrosis continued and the repair stopped, and the femoral head collapse occurred. All femoral heads collapsed at the end of the 8th week in 50 ℃ for 20 minutes group and 60 ℃ for 10 minutes group. CONCLUSION: Microwave heating at 55 ℃ for 10 minutes is the optimal choice to develop a rabbit model of osteonecrosis of the femoral head.

Objective To explore the protective effects of dipeptidyl peptidase-4 inhibitor (DPP-4I) on AD-like neurodegenerative changes and its mechanism. Methods The human neuroblastoma cell line SH-SY5Y on the logarithmic phase was divided into six groups:control group (CON group, treated with PBS contained 1‰DMSO for 12 h), wortmannin intervention group (W group, treated with 0.03 μmol/L wortmannin for 12 h), DPP-4I intervention group (DPP-4I group, treated with 10μmol/L DPP-4I for 12 h), both DPP-4I and wortmannin intervention group (DPP-4I+W group, pre-treated with 10 μmol/L DPP-4I for 2 h, then 0.03 μmol/L wortmannin for 12 h), DPP-4I, wortmannin and Ex9-39 intervention group (DPP-4I+W+Ex9-39 group, pre-treated with 10μmol/L Ex9-39 for 2 h, then 10μmol/L DPP-4I for 2 h followed by 0.03μmol/L wortmannin for 12 h), and Ex9-39 intervention group (Ex9-39 group, treated with 10μmol/L Ex9-39 for 12 h). MTT assay was used to detect the cell vitality. Western blot assay was used to detect the level of total tau protein (tau-5) and phosphorylated tau at different sites (pSpS199/202, pT231 and pS396), the level of phosphorylated neurofilaments (NF-H, NF-M) and phosphorylation of critical enzyme in PI3K/Akt/GSK-3β signaling pathway. Results (1) The cell vitality decreased, the levels of pSpS199/202, pT231, pS396 and NF-H/M increased significantly in W group than those in CON group. However, comparing with CON group, the above mentioned parameters reversed in DPP-4I group. Comparing with W group, the cell vitality increased and phosphorylated levels of above mentioned indices were decreased in DPP-4I+W group. (2) The cell vitality showed a decline trend while the levels of phosphorylation tau at three different sites and NF-H/M were higher in Ex9-39 group than those in CON group. Comparing with DPP-4I+W group, the results of the phosphorylated levels showed the same changes in DPP-4I+W+Ex9-39 group. (3) Comparing with CON group, the expression levels of phosphorylated PI3K, Akt and GSK3β increased significantly in DPP-4I group, while those decreased in W group. Additionally, the expression levels of phosphorylated PI3K, Akt and GSK3β were significantly increased in DPP-4I+W group than those in W group. Conclusion DPP-4I can enhance the level of GLP-1 and activate PI3K/Akt/GSK-3βinsulin signaling pathway to improve the hyperphosphorylated tau and NFs induced by wortmannin, and to protect AD-like neurodegeneration.

Objective To evaluate the impact of 3-dimensional ordered subset expectation maximization (3D-OSEM),2-dimensional ordered subset expectation maximization (2D-OSEM),filtered-back projection (FBP),and the number of OSEM iterations and subsets on quantitative results in SPECT/CT.Methods A Jaszczak cylindrical phantom and NEMA/IEC body phantom were performed in routine SPECT/CT using CT attenuation correction,scatter correction and 3D-OSEM reconstructed image.The system volume sensitivity (cpm/kBq) was acquired from the reconstructed image of Jaszczak phantom,and the absolute activity concentration (kBq/ml) of the hot sphere from IEC phantom was calculated and compared with true activity concentration,then quantitative error was calculated.With changing the reconstruction algorithm (2D-OSEM,FBP) and OSEM reconstruction parameters (number of iterations and subsets) to reconstruct the IEC phantom,the differences of quantitative results from different reconstruction algorithms and OSEM iterations and subsets were compared.Results When reconstructing images with 3D-OSEM,2D-OSEM and FBP,the quantitative error of each sphere increased with the decrease of the spherical volume (r=-0.831,-0.831,-0.826,all P＜0.05).The quantitative error of different volume spheres among three reconstruction algorithms was statistically significant (F=8.850,P＜0.05).Among them,the result of 3D-OSEM was less than that of 2D-OS EM (P＜0.05),and of 2D-OSEM was less than of FBP (P＜0.05).The quantitative error of different volume spheres decreased with the increasing of number of iterations (r=-0.721,-0.681,-0.691,-0.711,-0.845,-0.893,all P＜0.05) and decreased with the increase of number of subsets (r=-0.670,-0.694,-0.717,-0.852,-0.956,-0.998,all P＜0.05).Conclusion The quantitative accuracy of 3D-OSEM reconstruction based on CT attenuation correction and scattering correction is significantly better than that of 2D-OSEM and FBP.Choosing the appropriate OSEM reconstruction parameters is helpful to improve the quantification accuracy in SPECT/CT.

Objective To evaluate the effect of pyruvate peritoneal resuscitation on Janus kinase (JAK) /signal transducer and activator of transcription (STAT) signaling pathway in intestinal tissues of rats with hemorrhagic shock.Methods Twenty-four healthy male Sprague-Dawley rats,weighing 200-300 g,were divided into 3 groups (n=8 each) using a random number table method:sham operation group (S group),intravenous resuscitation group (VR group),and peritoneal resuscitation with pyruvate group (PY group).Hemorrhagic shock was induced by blood-letting and infusing blood withdrawn with mean arterial pressure reduced to 30-40 mmHg for 60 min in pentobarbital-anesthetized rats.Hemorrhagic shock was resuscitated with autologous blood and normal saline 2 times the volume of blood withdrawn at the end of hemorrhagic shock in group VR.Pyruvate was intraperitoneally infused for 30 min using a micro-perfusion pump simultaneously with the intravenous resuscitation in group PY.The animals were sacrificed at 2 h after resuscitation,and intestinal tissues were obtained for determination of malondialdehyde (MDA) content (by thiobarbituric acid method),superoxide dismutase (SOD) activity (using xanthine oxidase method),myeloperoxidase (MPO) activity (using chemical colorimetry),and expression of phosphorylated STAT3 (pSTAT3),phosphorylated JAK2 (p-JAK2) and caspase-3 expression (by Western blot).Results Compared with group S,the MDA content and MPO activity were significantly increased,the SOD activity was decreased,and the expression of p-STAT3,p-JAK2 and caspase-3 was up-regulated in the other two groups (P＜0.05).Compared with group VR,the MDA content and MPO activity were significantly decreased,the SOD activity was increased,and the expression of p-STAT3,p-JAK2 and caspase-3 was down-regulated in group PY (P＜0.05).Conclusion The mechanism by which peritoneal resuscitation with pyruvate mitigates intestinal damage may be related to inhibiting activation of JAK/STAT signaling pathway in the rats with hemorrhagic shock.

Objective To investigate the differences of acquisition protocols from continuous bed motion (CBM) and step-and-shoot (SS) modes and to observe their effects on image quality and standard uptake value (SUV) in 18 F-fluorodeoxyglucose (FDG) PET/CT.Methods A total of 30 patients (13 males,17 females;40-71 years) who underwent 18F-FDG PET/CT from June 2017 to September 2017 were selected.Simulated acquisition protocols for a specific range (upper margin of the skull to the lower edge of sciatic bone) were established with CBM and SS modes.The differences between 2 modes for actual length requiring for a specific acquisition range and the differences in CT radiation dose were compared.Real PET/ CT scans were performed using CBM and SS modes consecutively,and the differences in image quality and SUV were compared.Paired t test andx2 test were used to analyze the data.Results For the specific acquisition range,the average acquisition length of CBM was reduced by 6.65％ ((87.11 ± 3.78) vs (93.32 ±6.02) cm;t=-7.737,P＜0.001) and the CT radiation dose was reduced by 6.88％ ((812±170) vs (872±192) mGy · cm;t=-6.432,P＜0.001) for each patient compared with the results of SS.There were no significant differences in maximum SUV (SUVmax) and mean SUV (SUVmean) between SS and CBM in normal tissues including liver,bone and waist muscles (t values:from-1.895 to 0.132,all P＞0.05).The SUVmax of leg muscles at the end of the image was significantly higher in SS than that in CBM (1.24±0.53 vs 1.06±0.42;t=3.450,P＜0.01).There were no statistically significant differences in SUVmax and SUV between SS and CBM in 40 FDG high uptake lesions (t values:0.420 and-0.260,both P＞0.05).There were 73.33％ (22/30) patients had images with overall high quality during SS and the percentage was 80.00％ (24/30) during CBM (x2 =0.373,P＞0.05).The percentage of patients with images of high quality at the end was 16.67％(5/30) during SS,which was significantly less than that during CBM (63.33％,19/30;x2 =13.611,P＜0.001).Conclusions For the specific acquisition range,CBM can reduce unnecessary CT scan range and radiation dose compared with SS.There is no significant difference in image quality and SUV from normal tissue and lesion except for the end of the image.

Objective To understand the probability of premature mortality caused by non-communicable diseases (NCD) in Beijing from 2010 to 2015.Methods The data of deaths from Beijing vital registration system were used to analyze age-standardized NCD mortality rates,proportion of NCD deaths in age group ＜70 years and premature NCD mortality.Results NCD deaths accounted for 90％ of the total deaths in Beijing.Age-standardized NCD death rate decreased from 332.43/100 000 in 2010 to 280.02/100 000 in 2015.Meanwhile,the probability of deaths from four NCDs between in age group 30-70 years (premature NCD mortality) decreased from 12.81％ to 11.11％ in Beijing.The premature mortality of four NCDs in men was 14.63％,and compared with 2015 baseline,it would decrease by 16.4％ to reach 2025 goal (12.23％),and the probability of premature mortality four NCDs in women was 7.54％,and compared with 2015 baseline,it would decrease by 6.8％ to reach the 2025 goal (7.03％).People living in suburb areas had a higher probability of premature NCD mortality (13.67％) than those living in urban areas (9.72％) in Beijing in 2015.Conclusions The premature NCD mortality was much higher in men than in women in Beijing.More attention should be paid to the control of risk factors for NCD premature deaths,especially in men and in suburb residents,to reach the 25 × 25 goal.

Objective To investigate the methodology for absolute quantification with SPECT/CT using specified reconstruction algorithms and correction methods,and to determine the influence factors for quantitative accuracy.Methods The routine SPECT/CT imaging were performed with Jaszczak cylindrical phantom and International Electrotechnical Conmission (IEC) body phantom using a given acquisition and reconstruction parameter.The system volume sensitivities(SvoI)were acquired from the reconstructed images of Jaszczak phantom study.The absolute radioactivity of the hot spheres from IEC phantom study was calculated,and then the quantitative accuracies were checked.Differences of absolute quantitative value on quantitative accuracy were compared between 3 dimensional (3D)-ordered-subsets expectation maximization (OSEM) and 2 dimensional (2D)-OSEM,CT attenuation correction (AC) and no attenuation correction (NOAC),scatter correction (SC) and no scatter correction (NOSC),partial volume effect (PVE) correction and no PVE correction.Two-sample t test,one-way analysis of variance and Pearson correlation analysis were used.Results When 3D-OSEM,CTAC,SC and PVE correction were used,the average difference between absolute quantitative value and true value (374 kBq/ml) was-2.49％ in 6 hot spheres,and there was no obvious correlation between the quantitative error and the spheres volume (r=-0.795,P＞0.05).In the absence of PVE correction,the quantitative error of each sphere increased with the decrease of sphere volume (r=-0.852,P＜0.05).Differences of the quantitative value and the true value for 6 hot spheres among different reconstruction/correction methods were statistically significant (F =826.631,P＜0.05).The difference was smaller in 3D-OSEM+CTAC+NOSC than that in 2D-OSEM+CTAC+NOSC:(52.83±13.79) vs (61.33 ± 15.00) k Bq/ml (P＜0.05).The similar results were found when comparing differences between 3DOSEM+CTAC+SC and 3D-OSEM+CTAC+NOSC,also between 3D-OSEM+CTAC+NOSC and 3D-OSEM+ NOAC+NOSC:(9.33±5.47) vs (52.83±13.79) kBq/ml,(52.83±13.79) vs (307.66±9.24) kBq/ml (both P＜0.05).Conclusions An accurate absolute quantitative value could be obtained with 3D-OSEM reconstruction algorithm,CTAC,SC and PVE correction in SPECT/CT imaging.

Objective:To explore the influence of time of flight (TOF) and point spread function (PSF) on PET/CT image quality and standardized uptake value (SUV) based on a phantom study.Methods:PET/CT imaging were performed using Jaszczak phantom and International Electrotechnical Commission (IEC) body phantom respectively, and conventional clinical imaging protocol (3 min/bed) was used for three consecutive imaging. The ordered subsets expectation maximization (OSEM), OSEM+ TOF, OSEM+ PSF and OSEM+ TOF+ PSF were used to reconstruct the raw data respectively. The differences of image resolution, image uniformity, contrast, signal to noise ratio (SNR) and SUV among different reconstruction algorithms were compared by using one-way analysis of variance and the least significant difference (LSD) t test. The correlations between SNR, mean SUV (SUV mean), maximum SUV (SUV max) and the sphere diameter were analyzed by Pearson correlation analysis. Results:The minimum image resolution for the hot column was 6.4 mm by OSEM and OSEM+ PSF reconstruction, while it was 4.8 mm by OSEM+ TOF and OSEM+ TOF+ PSF reconstruction. The contrast was significantly better by OSEM+ TOF ((78.56±1.21)%) and OSEM+ TOF+ PSF ((78.85±1.17)%) reconstruction than that by OSEM reconstruction ((73.44±1.47)%; F=61.068, t values: 9.503, 10.018, both P<0.001). The maximum and minimum nonuniformity percentages were significantly better for images reconstructed with OSEM+ PSF than those reconstructed with OSEM ( F values: 10.286, 27.630, t values: -2.599, 7.698, both P<0.05). In IEC phantom imaging, the SNR and SUV max of hot sphere were higher by OSEM+ PSF and OSEM+ TOF+ PSF reconstruction than those by OSEM reconstruction (SNR: (98.99±34.76)%, (98.29±28.66)%, (73.64±26.05)%; F=5.712, t values: 3.209, 3.412, both P<0.05; SUV max: 8.96±2.72, 9.28±2.17, 8.01±2.21; F=3.931, t values: 2.154, 2.863, both P<0.05), but there was no significant difference between OSEM+ TOF and OSEM reconstruction ( t values: 0.297, 0.272, both P>0.05). Among the four reconstruction methods, the SNR and SUV mean increased with the increase of the sphere diameter ( r values: 0.913-0.963, all P<0.05), but SUV max in images reconstructed with OSEM+ PSF and OSEM+ TOF+ PSF had no significant correlations with the sphere diameter ( r values: 0.496, 0.614, both P>0.05). Conclusions:Under specific acquisition and reconstruction conditions, TOF mainly improves image resolution and contrast, while PSF mainly improves image uniformity and SNR. The combination of the two method can obtain better image quality and significantly improve the SUV of hot lesions.

Objective To explore the quantitative determination of standardized uptake value(SUV)of lumbar vertebra by 99Tcm-methylene diphosphonate(MDP)bone imaging with SPECT/CT.Methods A total of 90 patients(16 males,74 females,age:(60.0±11.2)years)who underwent 99Tcm-MDP bone imaging and local lumbar SPECT/CT imaging from May 2017 to November 2017 were retrospectively analyzed.CT attenuation correction,scatter correction and 3-dimensional ordered subset expectation maximization(3D-OSEM)reconstruction were used.The radioactive counts of lumbar vertebra LL-L4 in patients with high MDP-uptake(including degenerative changes and bone metastases)and patients with non-high MDP-uptake(including osteoporosis and non-osteoporosis)were measured.Basing on that,the radioactivity of unit volume in lumbar and lesion was calculated and converted to SUV.The difference of SUV for lumbar and lesions from different types of patients was analyzed,and the correlation between lumbar SUV and varies of parameters were also analyzed.Data were analyzed by two-sample t test and Pearson correlation analysis.Results The mean SUV(SUVmean)and maximum SUV(SUVmax)of L1-L4 in 54 patients with non-high MDP-uptake were 4.64±1.03 and 7.09±1.61 respectively.They were positively correlated with bone mineral content,CT value and body weight(r values:0.433-0.700,all P<0.05),and negatively correlated with age(r values;-0.514 and -0.456,both P<0.001).The SUVmean and SUVmax of patients with osteoporosis were 3.81±0.76 and 5.86±1.34 respectively,which were significantly lower than those of non-osteoporosis(5.13±0.84 and7.82±1.30;t values:-5.892 and-5.240,both P<0.001).The SUVmean and SUVmax of 37 metastases were 16.40±6.07 and 24.25±11.35 respectively in 16 patients,which were significantly higher than those in patients with degenerative changes(20 patients with 27 lesions;9.30±3.16 and 13.48±5.21;t values:6.074 and 5.083,both P<0.001).Conclusion Based on the specific reconstruction algorithm and correction method,the SUV of lumbar vertebra on 99Tcm-MDP SPECT/CT bone imaging can be obtained,and the bone mineral metabolism can be reflected.