BACKGROUND:Radiation-induced brain injury has recently become an increasing area of research, in particular in animal experimental studies. Domestic and international researches show that there have been no uniform scanning parameters used for examination of animal models of radiation-induced brain injury by magnetic resonance imaging. In this study, we performed magnetic resonance imaging in rabbits to determine related sequence parameters. OBJECTIVE:To establish the New Zealand rabbit models of radiation-induced brain injury, and obtain the brain magnetic resonance images of rabbits using LOOP7 coil, so as to provide experimental evidence for diagnosis of radiation-induced brain injury by magenetic resonance imaging. METHODS:Each of T2-weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy and magnetic susceptibility-weighted imaging were performed several times through the use of LOOP7 coil, to determine the optimal scanning parameters for each sequence. Rabbit models of radiation-induced brain injury were established and then their right hemispheres were irradiated using 6 MV X-rays at a single dose of 40, 80 and 120 Gy. The daily performance and dynamic magnetic resonance signs of rabbits were observed. The brain tissue was taken for pathological examination once abnormal magnetic resonance findings were observed or after 20 weeks of folow-up. RESULTS AND CONCLUSION:Only one rabbit model in the 40 Gy group had subdural hemorrhage. In the 80 Gy group, abnormal T2-weight imaging signals were observed in al rabbit models, which were pathologicaly confirmed as scattered degenerated neurons and infiltrated neutrophils. The abnormal signals that gradualy expanded over time were seen in rabbits from the 120 Gy group by magnetic resonance imaging and were pathologicaly confirmed as radiation-induced brain injury loci. The results confirm that establishing rat models of radiation-induced brain injury using radiation therapy system can better simulate the pathological process of radiation-induced brain injury; moreover, this model can be applied to receive routine magnetic resonance examination with LOOP7 coil.

The effects of targeted silencing of heparanase gene by small interfering RNA (siRNA) on invasiveness and metastasis of osteosarcoma cells (MG63 cells) were investigated in the present study. Two complementary oligonucleotide strands were synthesized and inserted into pGenesil-1 vector based on the mRNA sequence of heparanase gene. The expression vector containing short hairpin RNA (pGenesil-shRNA) was constructed successfully. MG63 cells were randomly allocated into 3 groups: blank group, empty vector (pGenesil) transfected group and expression vector (pGenesil-shRNA) transfected group. Under the induction of Lipofectamine 2000, the recombinants were transfected into MG63 cells. Heparanase gene expression level was detected by RT-PCR and Western blotting. Cell proliferation was measured by MTT assay. Cell invasiveness and metastasis were examined by cell adhesion and Transwell-ECM assays. HUVECs migration assay was applied for the detection of angiogenesis. As compared with negative controls, the mRNA and protein expression levels of heparanase were down-regulated by 76.1% (P<0.01) and 75.3% (P<0.01) respectively in the pGenesil-shRNA transfected group. Meanwhile, the proliferation, adhesiveness, invasiveness and angiogenesis properties of MG63 cells were all significantly inhibited. It was suggested that targeted silencing of heparanase gene by siRNA could dramatically inhibit the invasiveness and metastasis of osteosarcoma cells.

Objective To compare the displacements of the clips in the cavity measured with orthagonal kilovoltage (KV) X-my plain film in conditions of moderate deep inspiration breathing hold(mDIBH) and free breath (FB), and compare the margins from clinical target volume (CTV) to planning target volume (PTV) based on the displacements. Methods Before radiotherapy, 2 and 5 sets of orthogonal KV plain film were respectively collected in mDIBH and FB group, then the automatic registration of the reconstructed KV plain film and DRR derived from the planning OF images was finished. In conditions of mDIBH and FB, the displacements of the selected clip at the same location in the different directions and of the different selected clips in the same direction were compared. The margins in three dimensional directions were calculated and compared in conditions of mDIBH and FB . Results In FB hold group, the difference of displacement in left-right (LR), cranial-caudal (CC) and anterior-posterior (AP) directions were statistically significant between the clips at the cranial and caudal border of the cavity (9. 7 mm and 10. 6 nun (Z = -2. 12,P =0. 037) ,7. 3 mm and 8. 3 mm (Z = -2. 31 ,P=0. 041) ,15.5 mm and 16. 1 nun (Z = -2. 32,P = 0. 041)), but not statistically significant for the clips at the bottom and lateral P=0.814),15.7 mm and 16.5 mm (Z=-0.26,P=0.856)). The corresponding differences in the different directions were statistically significant (5.0 mm and 7. 8 mm(Z = -2. 31, P =0. 036), 5.0 mm and 9. 3 nun (Z= -2. 21,P=0. 021),7. 8 mm and9.3 mm (Z= -2. 11,P=0.041)). In FB group, the differences of the displacements of the four selected clips were statistically significant in CC and AP directions (7.3 mm and 8.4 mm (Z= -2.45,P=0.021), 15.5 mm and 16.5 mm (Z= -2.41,P= 0.043)), but not in LF direction (10.6 nun and 10.6 mm (Z= -0.24,P=0. 815)). In mDIBH group, the displacements in LF direction were statistically significant (4. 4 mm and 5.4 mm (Z = -2. 31, P = O. 031)), but not in CC and AP directions (8. 6 mm and 8.6 mm (Z =-0. 21, P = 0. 815), 10. 5 mm and 10. 8 mm (Z = -0. 27 ,P =0. 754)). There were statistically significant difference of the margins in LF and AP directions (9.7 mm and 5.0 mm (Z= -2.34,P=0.029),15.5 mm and 9.3 mm (Z= -2. 31,P= 0.021)), but not in CC direction (7.3 mm and 7. 8 mm (Z= -0.29,P =0.770)) between mDIBH and FB conditions. Conclusions The margins extended from CTV to PTV for EBPBI should be determined based on the respiratory status, border location and border direction.

Objective To investigate the association between endothelial dysfunction and arterial stiffness in continuous ambulatory peritoneal dialysis (CAPD) patients.Methods Ninetyfour stable CAPD patients from a single center were enrolled in this cross-sectional study.Ultrasound evaluation was conducted on brachial artery to estimate endothelial-dependent flow-mediated dilation (FMD).Automatice pulse wave velocity (PWV) measuring system was applied to examine the carotidfemoral PWV.Blood pressure and biochemical parameters were detected.Pearson's correlation and Stepwise multiple regression analysis were performed to explore the relationship between FMD and PWV.Results PWV was significantly higher in patients with diabetes as compared to those without diabetes[(13.25± 1.66) m/s vs (11.24±1.92) m/s,P ＜ 0.01].Furthermore,PWV was positively correlated with age(r=0.319,P=0.002),SBP (r=0.289,P=0.005) and C-reactive protein (r=0.211,P=0.041),was negatively correlated with albumin (r =-0.429,P =0.001) and FMD (r=-0.466,P=0.001).In multivariate regression analysis,diabetes mellitus,albumin,FMD,age and SBP were independently associated with PWV after adjustment.Conclusion Endothelial dysfunction is associated with greater arterial stiffness in CAPD patients.

Objective To investigate the imaging features in CT/MR of pancreatic neuroendocrine tumors(PNETs) with multiple lesions and further deepen the understanding of this disease .Methods A retrospective review of 12 PNETs patients′radiological data with pancreatic tumors′numbers≥2 and confirmed by surgery or fine needle aspiration biopsy in Changhai Hospital were conducted .Five cases underwent pancreatic CT plain and enhanced scan , 2 cases underwent MRI plain and enhanced scan , and 5 cases underwent both CT and MRI scan .Results There were totally 46 lesions in 12 patients.There were 29 (63.0%) lesions located in the pancreatic head and neck , and 17(37.0%) lesions located in body and tail of pancreas.The sizes of the lesions ranged from 0.8 to 9.5 cm,and the median size was 2.9 cm.Forty-four (95.7%) of the tumors was round or oval , and 2 ( 4.3%) was lobulated;44 ( 95.7%) mass solid and 2 (4.3%) was cystic.CT plain scan detected punctate , crescent or nodular calcification in 8(17.4%) lesions;enhanced scan found 42 lesions(91.4%) were markedly enhanced in the arterial phase , 2 lesions (4.3%) were markedly enhanced in the pancreatic phase;2 lesions (4.3%) were slightly enhanced and the degree of enhancement was lower than that of the normal pancreas .Four cases (33.3%) had dilatation of pancreatic duct and/or the bile duct, 4 cases (33.3%) had distant organ metastasis, 2 cases (16.7%) had lymph node metastasis, and 3 cases (25.0%) had vascular invasion .Conclusions PNETs can be multiple and vary in the size.Most of the lesions are round or oval solid lesions and the malignant signs for organ metastasis can be found occasionally .In dynamic enhanced scanning , the obvious enhancement of the solid portion in the tumor and the higher enhancement degree than that of normal pancreas is the main characteristic .

The purity of 4,4′-dimethoxy-5,6,5′,6′-bis (methylenedioxy)-2′-morpholine methylenebiphenyl-2-methyl formate methanesulfonate (IMH), a new drug for fatty liver treatment, was determined through differential scanning calorimetry (DSC). Analysis of two-factor non repeatability method was performed in the investigation the effects of two factors (heating rate and sample weight) on purity determination. The DSC experimental parameters were optimized as follows: heating rate was 10 ℃·min^-1, temperature range was 150-300 ℃, sample weight was 2.0-4.1 mg, and N₂ flow rate was 80 mL·min^-1. The linear correlation coefficient (r) of this DSC method was 0.999 8. The RSD value (n = 6) of precision was 0.03%. The standard value and uncertainty of the purity results of the multiple batches of IMH drugs were (99.74 ± 0.29)%, (99.91 ± 0.28)%, (99.90 ± 0.28)%, and (99.81 ± 0.28)% with inclusion factor (K) of 2 and confidence probability (P) of 0.95. The results were basically consistent with the results of the mass balance method. The DSC mehod is a simple, rapid and accurate method, and provides a new reference method for determining the purity of IMH drugs, improves the accuracy and reliability of purity determination.

OBJECTIVE: To investigate the changes of ryanodine receptor 2 (RyR2) mRNA expression in rats suffering from acute myocardial ischemia. METHODS: SD rats were divided randomly into normal control group, myocardial ischemia group and sudden death group. The models of myocardial ischemia and sudden cardiac death were induced by intraperitoneal injection of hypophysine. The changes of RyR2 mRNA expression in cardiac sarcoplasmic reticulum (SR) of rats suffering from myocardial ischemia were detected by fluorescent RT-PCR technique. RESULTS: The levels of RyR2 mRNA in the myocardial ischemia group and sudden death group were significant lower than those in the control group (P<0.05). CONCLUSION Myocardial ischemia may induce down-regulation of cardiac SR RyR2 mRNA expression.
Animals ; Death, Sudden, Cardiac ; Down-Regulation ; Female ; Forensic Pathology ; Male ; Myocardial Ischemia/metabolism* ; RNA, Messenger/metabolism* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction/methods* ; Ryanodine Receptor Calcium Release Channel/metabolism* ; Sarcoplasmic Reticulum/metabolism*

OBJECTIVETo investigate the relationship between mRNA expression of manganese superoxide dismutase (MnSOD) and manganese neurotoxicity.

METHODSThirty-one patients with occupational chronic manganese poisoning (case group), as well as 31 controls exposed to the same condition (control group), were included in the study. Whole blood RNA was extracted, and the mRNA expression of MnSOD was measured by RT-PCR; the two groups were compared in terms of the mRNA expression of MnSOD. PC12 cells were treated with 0, 100, 200, 400, 600, 800, and 1000 ümol/L MnCl₂ for l, 2, 3, and 4 d; the cell viability was determined by MTT assay, and the mRNA expression of MnSOD was measured by RT-PCR.

RESULTSThe case group had significantly lower mRNA expression of MnSOD than the control group (0.390 ± 0.080 vs 0.582 ± 0.219, P < 0.05). MnCl2 had a toxic effect on PC12 cells; the concentration of MnCl₂ was positively correlated with the toxic effect but negatively correlated with the mRNA expression of MnSOD.

CONCLUSIONMnSOD mRNA may be involved in the manganese-induced damage of nerve cells. It is hypothesized that high mRNA expression of MnSOD may play an inhibitory effect on manganese neurotoxicity.

Adult ; Animals ; Female ; Gene Expression ; Humans ; Male ; Manganese Poisoning ; genetics ; Middle Aged ; Neurotoxicity Syndromes ; genetics ; PC12 Cells ; RNA, Messenger ; genetics ; Rats ; Superoxide Dismutase ; genetics

The effects of targeted silencing of heparanase gene by small interfering RNA (siRNA) on invasiveness and metastasis of osteosarcoma cells (MG63 cells) were investigated in the present study.Two complementary oligonucleotide strands were synthesized and inserted into pGenesil-1 vector based on the mRNA sequence of heparanase gene.The expression vector containing short hairpin RNA (pGenesil-shRNA) was constructed successfully.MG63 cells were randomly allocated into 3 groups:blank group,empty vector (pGenesil) transfected group and expression vector (pGenesil-shRNA) transfected group.Under the induction of Lipofectamine 2000,the recombinants were transfected into MG63cells.Heparanase gene expression level was detected by RT-PCR and Western blotting.Cell proliferation was measured by MTT assay.Cell invasiveness and metastasis were examined by cell adhesion and Transwell-ECM assays.HUVECs migration assay was applied for the detection of angiogenesis.As compared with negative controls,the mRNA and protein expression levels ofheparanase were down-regulated by 76.1％ (P＜0.01) and 75.3％ (P＜0.01) respectively in the pGenesil-shRNA transfected group.Meanwhile,the proliferation,adhesiveness,invasiveness and angiogenesis properties of MG63 cells were all significantly inhibited.It was suggested that targeted silencing of heparanase gene by siRNA could dramatically inhibit the invasiveness and metastasis of osteosarcoma cells.

AIMTo explore the effect of androgen receptor (AR) on the expression of the cell cycle-related genes, such as CDKN1A and BTG1, in prostate cancer cell line LNCaP.

METHODSAfter AR antagonist flutamide treatment and confirmation of its effect by phase contrast microscope and flow cytometry, the differential expression of the cell cycle-related genes was analyzed by a cDNA microarray. The flutamide treated cells were set as the experimental group and the LNCaP cells as the control. We labeled cDNA probes of the experimental group and control group with Cy5 and Cy3 dyes, respectively, through reverse transcription. Then we hybridized the cDNA probes with cDNA microarrays, which contained 8 126 unique human cDNA sequences and the chip was scanned to get the fluorescent values of Cy5 and Cy3 on each spot. After primary analysis, reverse transcription polymerase chain reaction (RT-PCR) tests were carried out to confirm the results of the chips.

RESULTSAfter AR antagonist flutamide treatment, three hundred and twenty-six genes (3.93%) expressed differentially, 97 down-regulated and 219 up-regulated. Among them, eight up-regulated genes might be cell cycle-related, namely CDC10, NRAS, BTG1, Wee1, CLK3, DKFZP564A122, CDKN1A and BTG2. The CDKN1A and BTG1 gene mRNA expression was confirmed to be higher in the experimental group by RT-PCR, while p53 mRNA expression had no significant changes.

CONCLUSIONFlutamide treatment might up-regulate CDKN1A and BTG1 expression in prostate cancer cells. The protein expressions of CDKN1A and BTG1 play an important role in inhibiting the proliferation of cancer cells. CDKN1A has a great impact on the cell cycle of prostate cancer cells and may play a role in the cancer cells in a p53-independent pathway. The prostate cancer cells might affect the cell cycle-related genes by activating AR and thus break the cell cycle control.

Androgen Receptor Antagonists ; Antineoplastic Agents, Hormonal ; pharmacology ; Cell Cycle ; drug effects ; genetics ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; genetics ; Flutamide ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Male ; Neoplasm Proteins ; genetics ; Oligonucleotide Array Sequence Analysis ; Prostate-Specific Antigen ; genetics ; Prostatic Neoplasms ; drug therapy ; pathology ; RNA, Messenger ; analysis ; Reverse Transcriptase Polymerase Chain Reaction