Feasibility of optimizing acquisition time of 18F-FDG PET with BSREM reconstruction algorithm / 中国辐射卫生

Objective To compare the impact on 18F fluorodeoxyglucose （18F-FDG） positron emission tomography （PET） image quality when block sequential regularized expectation maximization （BSREM） algorithm and ordered subset expectation maximization （OSEM） algorithm were used at various acquisition times （ATs）, and to discuss the feasibility of AT optimization with BSREM algorithm. Methods In the phantom experiment, the NEMA/IEC PET phantom was adopted. In the clinical study, 66 pulmonary nodules with high uptake values from 61 patients who underwent a 18F-FDG PET-CT examination for pulmonary nodules from March to September 2020 were included. PET images were reconstructed according to BSREM algorithm and OSEM algorithm at various ATs in both the phantom experiment and the clinical study. Coefficient of variation, signal-to-noise ratio, contrast-to-noise ratio, and activity values （uptake value in the phantom experiment; standardized uptake value in the clinical study） were compared between the above sequence images for quality evaluation. Results The phantom experiment showed that the image quality of 120 s BSREM sequence was superior to that of 120 s OSEM sequence, and the image quality of 75 s BSREM sequence was similar to that of 120 s OSEM sequence. The clinical study showed that the image quality of 120 s BSREM sequence was superior to that of 120 s OSEM sequence, and the image quality of 75 s BSREM sequence was slightly better than that of 120 s OSEM sequence. Conclusion In the PET phantom experiment and the clinical study of pulmonary nodules with high uptake values, BSREM algorithm can significantly improve the image quality as compared to OSEM algorithm, and the image quality of 75 s BSREM sequence is slightly better than that of 120 s OSEM sequence.

Construction and identification of a recombinant PRRSV expressing ORF2 of porcine circovirus type 2 / 病毒学报

Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are very two important pathogens that have coursed huge economic losses in swine production in worldwide. In this study,a vector pCMV-TJM containing the full-length cDNA clone of PRRSV attenuated strain TJM-F92 was firstly constructed by PCR method. Then a gene sequence containing Afl II/Mlu I e restriction enzyme sites and a transcription regulatory sequence for ORF6 (TRS6) was inserted be- tween ORF7 and 3'UTR, yielding a expression vector pCMV-TJM-TRS. Subsequently, a plasmid pCMV-TJM-Cap was constructed by cloning of PCV2 ORF2 gene into the unique sites Afl II /Mlu I of pCMV- TJM-TRS plasmid DNA. Then three recombinant PRRSV, rTJM, rTJM/TRS and rTJM/Cap, were rescued by transfection of pCMV-TJM, pCMV-TJM-TRS and pCMV-TJM-Cap into Marc-145 cells, respectively,and confirmed by the genome sequence, restriction enzyme digestion, Western Blot and IFA. They all had the molecular markers which was different from the parent virus. The growth characteristics of the rescued viruses were similar to that of parent virus. rTJM/Cap could also express efficiently PCV2 Cap protein in Marc-145 cells. At passage 8, it still had PCV2 ORF2 gene which examined by RT-PCR. It indicated that the full-length cDNA clone of PRRSV attenuated strain TJM-F92 and recombinant PRRSV rTJM/Cap expressing PCV2 Cap protein were successfully constructed. It made an important foundation for studying on the pathogenic mechanisms of PRRSV and PRRSV-PCV2 vaccine in the future.

Role of NF-κB in astrocytes in spinal dorsal horn in a rat model of neuropathic pain induced by paclitaxel / 中华麻醉学杂志

Objective To evaluate the role of NF-κB in astrocytes in the spinal dorsal horn in a rat model of neuropathic pain induced by paclitaxel.Methods Twenty 6 year old male SD rats weighing 180-200 g were randomly divided into 2 groups ( n =10):control group (group C) and neuropathic pain group (group NP).Neuropathic pain was induced by intraperitoneal injection paclitaxel of 2 mg/kg every other day for 4 times in group NP.While the equal volume of normal saline was given instead of paclitaxel in group C.Body weight,mechanical pain threshold and heat pain threshold were determined before and at 1,7,14 d after administration.The animals were sacrificed and the spinal dorsal horn were removed for determination of NF-κB p65 expression in astrecytes by immunofluorescence analysis at 14 d after administration.Results There was no significant difference in body weight between the two groups( P ＞ 0.05).Compared with group C,mechanical pain threshold and heat pain threshold were significantly decreased 7 and 14 d after administration,the expression of NF-κB p65 in astrocytes in the spinal dorsal horn was up-regulated in group NP( P ＜ 0.05 or 0.01 ).Conclusion Activation of NF-κB in astrocytes in the spinal dorsal horn may play an important role in neuropathic pain induced by paclitaxel in rats.

An epidemiological study of abnormal glucose metabolism and its risk factors among middle and aged population with hypertension in Chengdu area / 中华内科杂志

Objective To explore the epidemiological status of abnormal glucose metabolism and its influential factors among middle and aged population with hypertension in Chengdu area. Methods In 2008, after adopting the methods of stratified cluster sampling, the authors investigated 4685 subjects of the middle and aged population between the age of 40-79 in Chengdu urban and rural area by checking blood pressure and oral glucose tolerance test (OGTY). Patients with previously known diabetes mellitus (DM) were only asked to perform fasting glucose and to carry out a questionnaire. Comparison of the prevalence rates of abnormal glucose metabolism in hypertensive and non-hypertensive subjects was carried out. The prevalence rates of isolated impaired glucose tolerance (I-IGT) and isolated postprandial hyperglycemia (IPH) among middle and aged subjects with hypertension were acquired and the influential factors of abnormal glucose metabolism among middle and aged subjects with hypertension were analyzed. Results The prevalence rate of abnormal glucose metabolism in the hypertensive subjects was obviously higher than that in the non-hypertensive subjects; without using OGTT, 72.9% of the pre-diubetic and 54. 4% of the new diagnosed DM patients would remain undiagnosed if fasting plasma glucose detection was used alone. Age, diabetic history of first degree relatives ,overweight or obesity were the risk factors for the development of abnormal glucose metabolism among middle and aged male subjects with hypertension in Chengdu area. Exercise training and high education level were the protective factors. Age, diabetic history of first degree relatives,abdominal obesity and hypertriglyceridemia were the risk factors for the development of abnormal glucose metabolism among middle and aged female subjects with hypertension in Chengdu area. Conclusions More than 50% of middle and aged subjects with hypertension in Chengdu area has accompanying abnormal glucose metabolism. OGTT easily discloses the abnormal status and should be a routine procedure in the diagnosis of pre-diabetes or DM in such population. Appropriate exercise, learning diabetes-related knowledge to take reasonable lifestyle, and intervention of metabolic factors such as overweight or obesity are advised. Abdominal obesity and hypertriglyceridemia play important roles in leading to abnormal glucose metabolism among middle and aged population with hypertension.

Hippocampal bcl-2 and bax expressions and neuronal apoptosis after moderate hypothermic cardiopulmonary extracorporeal circulation in rats / 中国组织工程研究

BACKGROUND: Hippocampus injury is wildly believed to involve in neurocognitive dysfunction; the establishment of a rat model of cardiopulmonary bypass(CPB) allows us to investigate the mechanism of CPB-related hippocampus injury.OBJECTIVE: To investigate the effects of moderate hypothermic CPB with a hemodilution on hippocampal bcl-2 and bax gene expression and neuronal apoptosis in rats.DESIGN: A randomized group division study based on the experimental animals.SETTING: Department of anesthesiology in a university hospital.MATERIALS: Thirty Sprague-Dawley (SD) rats were randomly divided into two groups, CPB group and sham-CPB group with 15 rats in each group.METHODS: Total 15 rats of CPB group were subjected to 60-minute moderate hypothermic nonpulsatile CPB using a peristaltic pump and a membrane oxygenator. The CPB circuit was primed with approximately 20 mL 1:1crystaloid-colloid liquid, while another 15 rats of sham-CPB group underwent identical anesthetic and surgical procedures(including cannulation) except CPB itself. At 1 hour post-CPB, six rats in each group were decapitated, and hippocampi were removed, homogenized, and processed for apoptotic gene ( bcl-2 and bax) mRNAs detection. Reverse transcriptase polymerase chain reaction(RT-PCR) is used to detect expression of mRNA by comparing the PCR product of bcl-2 or bax to those of β-actin housekeeping gene. Immunohistochemistry is used to detect bcl-2 and bax protein expressions and terminal deoxynucleiotidyl transferase-mediated dUTP-biotion nick end labeling(TUNEL) staining method was used to detect neuronal apoptosis at 6 hours post-CPB ( n = 6 in each group) . The protein expression was quantitated as percentage of the positively stained area in the total stained. In addition, hippocampal neuronal ultrastructures were studied by electron microscopy at 6 hours post-CPB( n = 3 in each group).ronal apoptosis and ultrastructure changes between the two groups.RESULTS: At 1 hour post-CPB, the expressions of bcl-2 and bax gene, and the ratio of bax to bcl-2 in CPB group were significantly increased compared with those of sham-CPB group( P ＜ 0.05) . At 6 hours post-CPB, the expressions of Bcl-2 and Bax protein in hippocampal CA1 region had significantly increased in CPB group(P ＜ 0.05) . TUNEL staining showed that hippocampal CA1 neuronal apoptosis was significantly increased in CPB group compared with sham-CPB group at 6 hours post-CPB( P ＜ 0. 05).Electron Microscopy demostrated that, at 6 hours post-CPB, neuronal ultrastructures in CPB group had obvious abnormalities, many mitochondria being moderately to severely swollen with vacuolation as well as decreasing number of mitochondrial cristae, some neurons having characteristic morphological changes of earlier periods of apoptosis such as neuronal pycnosis, irregular nucleus, nuclear membrane with notchs, chromatin condensation, and nucleoli movement to the nuclear periphery, etc.CONCLUSION: Moderate hypothermic CPB with a hemodilution can induce hippocampal bax, bcl-2 gene expression and neuronal apoptosis in rats,which maybe partly explain the mechanism of post-CPB neurocognitive dysfunction.

Relationship between cerebral oxygen metabolism during coronary artery bypass graft and postoperative mental disorders in geriatric patients / 中华麻醉学杂志

Objective To investigate the relationship between cerebral 0, metabolism during coronary artery bypass graft (CABG) performed with cardiopulmonary bypass (CPB) and postoperative mental disorders (POMD) in the elderly.Methods Thirty patients (13 male,17 female) aged 65-76 yr undergoing CABG performed with CPB were studied. Patients with senile dementia were excluded. The patients were premedicated with scopolamine 0.3 mg and pethidine 50mg. Anesthesia was induced with midazolam 0.05-0.1 mg?kg_(-1), propofol 0.2-0.5 mg?g_(-1), fentanyl 10-15?g?g_(-1) and vecuronium 0.1-0.3 mg?g_(-1) and maintained with isoflurane inhalation and intermittent iv boluses of fentanyl. Nasopharyngeal temperature (T) was maintained at 26℃-28℃) during CPB. Radial artery was cannulated for BP monitoring and blood sampling.Swan-Ganz was placed via right internal jugular vein (UV).Another catheter was inserted into right UV and threaded retrogradely until J point for blood sampling. Blood samples were taken from artery and UV simultaneously for blood gas analyses and determination of blood glucose and lactate concentration before anesthesia (T_1 ),immediately after induction of anesthesia (T_2), during splitting of sternum (T_3) when T was reduced to 28℃ (T_4) and rewarmed to 35℃(T_5 ) and at the end of bypass (T_6 ).Cerebral O2 delivery (CDO2 ),cerebral oxygen consumption (CMRO2),cerebral glucose consumption (CMRglu) and lactic acid production (ADVL) were calculated. POMD was assessed using CAM-ICU chart.Results (1)Seven patients developed POMD (7/30 or 23.3% ).(2) Low jugular bulb 02 saturation (SjO2 ≤50% or PjO2≤25% mm Hg) was observed in 8 patients during rewarming. The incidence was significantly higher in POMD patients (3/7 or 42.96%) than that in non-POMD patients (5/23 or 21.74%). (3) CBF/CMRO2 was significantly lower in POMD patients than in non-POMD patients during rewarming.(4) CMRO2/CMRglu was significantly lower but ADVL was significantly higher in POMD patients than in non-POMD patients during hypothermia, rewarming and at the end of CPB.(P

Effects of mild hypothermic cardiopulmonary bypass on neuronal apoptosis in hippocampus CA1 region in rats / 中华麻醉学杂志

Objective To investigate the effects of mild hypothermic cardiopulmonary bypass(CPB) on bax and bcl-2 protein expression and neuronal apoptosis in hippooampus CA1 region in rats. Methods Healthy male SD rats weighing 380-420g were randomly divided into 3 groups: (1)post-CPB 1h group (n=6); (2) post-CPB 6h group (n=6) and (3) sham CPB group(n=5). The animals were anesthetized with intraperitoneal fentanyl 150?g?kg~(-1), midazolam 1 mg?kg~(-1) and vecurunium 0.1 mg?kg~(-1), intubated and mechanically ventilated. Left femoral artery was cannulated for heparinizafion, BP monitoring and blood sampling. Artery in the tail and right jugular vein were cannulated for CPB. The animals in group 1 and 2 underwent 2 h mild hypothermic (26-28℃) CPB at a flow of 160 ml?kg~(-1)?min~(-1). 1h(group 1) and 6h(group 2) after CPB 4% polymerized formaldehyde was injected via the artery in the tail. Brains were immediately removed. Bax and bcl-2 protein expression in hippocampus CA1 region was determined by immuno-histochemistry method and neuronal apoptosis by TUNEL technique. Ultrastructural changes were examined with electron microscope. Results (1)Bax and Bcl-2 protein expressions were significantly higher in group 1(1h after CPB)than in sham CPB group. Bax protein expression was significantly higher but bcl-2 protein expression was significantly lower in group 2 than in group 1. bax/bcl-2 ratio in group 2(at 6h after CPB)was significantly higher than that in group 1(at 1h after CPB). (2) Neuronal apoptosis was significantly increased in group 1 and 2 compared to sham CPB group. (3) Electron microscopy showed that some mitochondria were moderately or severely swollen with vacuolizafion and decreased number of mitochondrial at 1h after CPB and at 6h after CPB there was shrinkage of neuronal cells with irregular shape of nucleus, notches in nuclear membrane and margination of nucleoli. Conclusion CPB induces upregulation of both bax and bcl-2 protein expression with predominance of the pro-apoptotic gene Bax leading to increased neuronal apoptosis, indicating that CPB can cause brain injury.