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pH-responsive antibacterial nanomaterials are a new type of nanomaterials that can selectively undergo structural changes and trigger drug release according to significant pH differences produced by the body under physiological and pathological conditions. The formation of acidic microenvironment in plaque is the key to the pathogenicity of oral plaque biofilm, which also creates conditions for the oral application of pH-responsive antibacterial nanomaterials. pH-responsive antibacterial nanomaterials can respond to changes in pH of plaque microenvironment and accurately control the release of antibacterial drugs, providing a new direction for improving drug efficacy and targeted antibacterial. The present article reviews the classification, mechanism and application of pH-responsive antibacterial nanomaterials in oral plaque inhibition.
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OBJECTIVES@#Staphylococcus epidermidis (S. epidermidis) is a Gram-positive opportunistic pathogen that often causes hospital infections. With the abuse of antibiotics, the resistance of S. epidermidis gradually increases, and drug repurposing has become a research hotspot in the treating of refractory drug-resistant bacterial infections. This study aims to study the antimicrobial and antibiofilm effects of simeprevir, an antiviral hepatitis drug, on S. epidermidis in vitro.@*METHODS@#The micro-dilution assay was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of simeprevir against S. epidermidis. Crystal violet staining assay was used to detect the biofilm inhibitory effect of simeprevir. The antimicrobial activity of simeprevir against S. epidermidis and its biofilm were explored by SYTO9/PI fluorescent staining. The combined effect between simeprevir and gentamycin was assessed by checkerboard assay and was confirmed by time-inhibition assay.@*RESULTS@#Simeprevir showed significant antimicrobial effects against S. epidermidis type strains and clinical isolates with the MIC and MBC at 2-16 μg/mL and 4-32 μg/mL, respectively. The antimicrobial effects of simeprevir were confirmed by SYTO9/PI staining. Simeprevir at MIC could significantly inhibit and break the biofilm on cover slides. Similarly, simeprevir also significantly inhibit the biofilm formation on the surface of urine catheters either in TSB [from (0.700±0.020) to (0.050±0.004)] (t=54.03, P<0.001), or horse serum [from (1.00±0.02) to (0.13±0.01)] (t=82.78, P<0.001). Synergistic antimicrobial effect was found between simeprevir and gentamycin against S. epidermidis with the fractional inhibitory concentration index of 0.5.@*CONCLUSIONS@#Simeprevir shows antimicrobial effect and anti-biofilm activities against S. epidermidis.
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Humans , Simeprevir , Antiviral Agents , Anti-Bacterial Agents/pharmacology , Cross Infection , GentamicinsABSTRACT
A case of amniotic band syndrome (ABS) was reported here. No obvious fetal abnormality was revealed by systematic ultrasound at 22+4 weeks of gestation. At 30 weeks of gestation, the pregnant woman was found to have excessive amniotic fluid and possible fetal edema according to ultrasound images and admitted to the First Affiliated Hospital of Nanjing Medical University. After admission, she received diet control to lower blood glucose and amniotic fluid reduction. The dynamic amniotic fluid index was measured by ultrasound, and the electrical fetal heart rate was monitored daily. Since 32 weeks of gestation, progressive reduction in fetal movement with sinusoidal fetal heart rate pattern was observed. An emergent cesarean section was performed due to fetal distress at a gestational age of 32+3 weeks. During the operation, a porous amniotic membrane was found, from the umbilical cord insertion of the placenta to the ankle of the left lower limb of the fetus. Amniotic band constricting left ankle of newborn and the edema of the left foot was obvious, then ABS was diagnosed. This amniotic band affected the left foot of the fetus directly, while there was not enough evidence whether the flake amniotic membrane near the umbilical cord insertion of the placenta could affect the fetus. This premature infant died of neonatal asphyxia 24 hours after birth.
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In this paper, we analyzed medical records of 40 patients with coronavirus disease 2019(COVID-19), in order to explore the clinical efficacy of Matrine and Sodium Chloride Injection in the treatment of COVID-19. The investigation was based on the results of a previous animal test, which was aimed to investigate and confirme the clinical efficacy of Matrine and Sodium Chloride Injection in the treatment of COVID-19. The animal test demonstrated that Matrine and Sodium Chloride Injection has a significant therapeutic effect on the human coronavirus pneumonia for the model mice. The lung inhibition index reached up to 86.86%. The evaluation was conducted on 40 confirmed cases of COVID-19 treated at Jingzhou Hospital of Infectious Disease(Chest Hospital) of Hubei Pro-vince from January 30~(th) to March 21~(th), 2020. In these cases, patients were treated with other integrated Chinese and Western medicines regimens in the recommended Matrine and Sodium Chloride Injection diagnosis and treatment regimen. The clinical manifestations, laboratory data, nucleic acid clearance time, and imaging data were compared and analyzed before and after treatment. After administration with Matrine and Sodium Chloride Injection, the clinical symptoms of 40 cases were alleviated markedly, and their blood analysis and biochemical indexes returned to normal. The lung CT showed more than 50% of lesion absorption rate, and the viral nucleic acid test showed the average clearance time of patients was 16.6 days, and the average length of hospital stay was 25.9 days. After administration with Matrine and Sodium Chloride Injection, the symptoms of cough and fatigue were alleviated significantly, and the appetite was significantly improved compared with before, especially for patients with gastrointestinal symptoms. Additionally, laboratory indicators, especially absolute value and ratio of lymphocytes and CRP were significantly alleviated. According to the chest CT for short-term review, the absorption of lung lesions was faster than before, especially for grid-like and fibrotic lesions. Compared with antiviral drugs, such as Abidol and Kriging, the nucleic acid clearance time was significantly shorter than the cases treated with Matrine and Sodium Chloride Injection. The clinical effective rate of 40 cases was 100.0%. We believed that Matrine and Sodium Chloride Injection have a good clinical effect in the treatment of COVID-19, and suggested increasing the clinical application and further conducting large-sample-size cli-nical verification.
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Animals , Mice , Alkaloids , Betacoronavirus , Coronavirus Infections , Disease Models, Animal , Pandemics , Pneumonia, Viral , Quinolizines , Sodium Chloride , Treatment OutcomeABSTRACT
A case of amniotic band syndrome (ABS) was reported here.No obvious fetal abnormality was revealed by systematic ultrasound at 22+4 weeks of gestation.At 30 weeks of gestation,the pregnant woman was found to have excessive amniotic fluid and possible fetal edema according to ultrasound images and admitted to the First Affiliated Hospital of Nanjing Medical University.After admission,she received diet control to lower blood glucose and amniotic fluid reduction.The dynamic amniotic fluid index was measured by ultrasound,and the electrical fetal heart rate was monitored daily.Since 32 weeks of gestation,progressive reduction in fetal movement with sinusoidal fetal heart rate pattern was observed.An emergent cesarean section was performed due to fetal distress at a gestational age of 32+3 weeks.During the operation,a porous amniotic membrane was found,from the umbilical cord insertion of the placenta to the ankle of the left lower limb of the fetus.Amniotic band constricting left ankle of newborn and the edema of the left foot was obvious,then ABS was diagnosed.This amniotic band affected the left foot of the fetus directly,while there was not enough evidence whether the flake amniotie membrane near the umbilical cord insertion of the placenta could affect the fetus.This premature infant died of neonatal asphyxia 24 hours after birth.
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Objective:To analyze the results of external quality assessment (EQA) of different levels laboratories of iodine deficiency disorders (IDD) in Inner Mongolia in 2018, and to understand the detection ability of these laboratories.Methods:In 2018, the Inner Mongolia region level laboratories and all 12 league and municipal level laboratories were assessed for salt iodine, urinary iodine and water iodine (74 banner, county and district level laboratories participated in the urinary iodine assessment, and 100 banner, county and district level laboratories participated in the salt iodine assessment). As 3+-Ce 4+ catalytic spectrophotometry (WS/T 107.1-2006) was used to measure the iodine in urine, direct titrimetric method (GB/T 13025.7.1-2012) was used to measure the salt iodine, and water iodine was determined based on "Determination of Iodine in Drinking Water by As 3+-Ce 4+ Catalytic Spectrophotometry" in the range of 0 - 100 μg/L. The examination results of EQA of different levels of IDD laboratories in Inner Mongolia were statistically analyzed. Results:Regional level leboratory passed all the 3 assessments, qualified rates of salt iodine, urinary iodine and water iodine were 83.3% (10/12), 91.7% (11/12), and 100.0% (12/12), respectively, at league and municipal level; qualified rates of salt iodine and urinary iodine were 95.0% (95/100), and 90.5% (67/74), respectively, at banner, county and district level in 2018.Conclusions:The detection ability of IDD laboratories at all levels in the whole region has been stabilized, but there are still fluctuations in some laboratories. It is suggested that the technical and responsibility training, instrument verification, experimental environment control and quality control of laboratories at all levels should be continued.
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Objective:To investigate the expressions of cardiac cycle, myocardial pathology, galectin-3 (Gal-3),transforming growth factor-β (TGF-β),Smad homologue 3 recombinant protein (Smad3) in rats with heart failure and heart failure after ischemia-reperfusion, and the intervention effect of Dendrobii Officinalis Caulis (DOC) myocardial fibrosis in model rats. Method:A rat model of heart failure and Qi deficiency was established through ligation of the left anterior descending coronary artery. The rats were divided into blank group, model group, valsartan group (9.43 mg·kg-1) and DOC group (10 mg·kg-1), with 10 in each group. The blank group and the model group were given an equal volume of physiological saline. The changes in left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic dimension(LVESD), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS) of the cardiac cycle of rats in each group were recorded by high-resolution ultrasound system. The carboxyterrninal propeptide of type I procollagen (PICP), and carboxyterrninal propeptide of type Ⅲ procollagen (PⅢNP)were detected by enzyme-linked immunosorbent assay (ELISA) kit. The morphological changes of myocardial cells were observed by hematoxylin-eosin (HE) staining. The changes of myocardial fiber tissue and collagen were observed by Masson staining. Western blot was used to detect the protein expressions of Gal-3, TGF-β, Smad3. Result:Compared with the blank group, the levels of LVEDD, LVEF, and LVFS were lower in the model group (PPβ, and Smad3 were decreased (PPPPβ and Smad3 were lower than those in the model group (PPConclusion:DOC can effectively inhibit myocardial fibrosis in rats with heart failure and heart Qi deficiency syndrome after ischemia-reperfusion. The mechanism may be correlated with the reduction of the expressions of Gal-3, TGF-β and Smad3.
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Acute and chronic pancreatitis are most common gastrointestinal diseases.Recently,there are emerging evidences that immune cell play important roles in the pathogenesis of acute and chronic pancreatitis.Studies have shown that macrophages,high mobility group protein 1 (HMGB 1) and interleukin-33 (IL-33) play an important role in the pathological process of pancreatitis,and are regulated by multiple levels.For example,immune cells are critical in the development and progression of pancreatitis,which not only have the ability to induce microenvironment,but also respond to danger signals derived from endogenous and exogenous molecules.Therefore,further understanding of relevant immune signaling will provide new idea and potential therapeutic targets that can prevent disease progression.Here,we review recent data from animal and human clinical studies that focus on immune responses.
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Objective To investigate the threshold of IgG anti-A (B) antibody with microcolumn gel method and analyze the correlations between the incidence of neonatal hemolytic disease and IgG antibody titer in pregnant women as well as their age for the guidance of prenatal early prevention.Methods Based on blood type of 3 463 perinatal pregnant women and their husbands,the titers of prenatal antibody IgG against A and B were determined by both microcolumn gel and test tube method.The 1 620 pregnant women with blood type O were divided into three groups according to different pregnancy times (1,2,3 or more than 3 times).The titers of serum IgG anti A and B were determined every 4 weeks from the 22th week using micro column gel method.The newborn hemolytic disease-related indicators were detected simultaneously.Results In this laboratory,256 of the antibody titer by microcolumn gel method was used as the indoor reference value.The geometric average titer of IgG anti-A was 169 in 2 257 person-times of perinatal women,and the titer of IgG anti-B was 143 in 1 711 person-times of perinatal women.The 1 620 women with blood type O were continuous monitored at different pregnant times.In 896 women with first pregnancy,260 cases (29.02％)showed 256 or more than 256 of IgG anti A (B)antibody titer,107 cases (43.15％) in 248 women with the second pregnancy showed 256 or more of IgG anti A (B) antibody titer,and 220 cases (46.70％) in 476 women with the third pregnancy or more showed 256 or more of IgG anti A (B) antibody titer.The average ages of the pregnant women with increased 1,2 and 3 antibody titers were 26.4,27.8 and 29.9 respectively,and the incidences of hemolytic disease of newborn (HDN) were 21.66％,40.94％ and 84.90％ respectively.Conclusion In detecting IgG antibody in prenatal serum of pregnant women with O type,the sensitivity of microcolumn gel method for IgG antibody should be obviously higher than that of the traditional test tube method.The reference value of microcolumn gel method or IgG antibody titer was obviously higher than that of test tube method.The positive rate of IgG anti-A antibody in multiple pregnancies was significantly higher than that in the first pregnancy.The incidence of HDN may increase with the age of pregnant women when the titer of IgG antibody increased by 2 or more titers.
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<p><b>OBJECTIVE</b>To observe the efficacy and safety of the Chinese medicine (CM) Compound Zhuye Shigao Granule (, CZSG) on acute radiation-induced esophagitis (ARIE) in cancer patients.</p><p><b>METHODS</b>In a blinded, randomized, Kangfuxin Solution (, KFX)-controlled, single-centre clinical trial, 120 patients with lung, esophagus or mediastinal cancer were prospectively enrolled and assigned to the treatment group (60 cases) and control group (60 cases) by the random number table method. All patients received concurrent or sequential radiotherapy (2 Gy per day, 5 times per week, for 4 weeks) and were treated for 4 weeks since the radiation therapy. Patients in the treatment group were given 12 mg CZSG orally, thrice daily, while patients in the control group were given 10 mL KFX orally, thrice daily. The major indicators were observed, including the incidence and grade of esophagitis, time of occurrence and duration. Minor indicators were changes of CM symptoms, weight and Karnofsky Performance Status (KPS) Scale during 4 weeks from the beginning, recorded once a week. Blood routine examination and hepatorenal function were detected at the 2nd and 4th weeks.</p><p><b>RESULTS</b>The incidence and grade of ARIE were significantly decreased in the treatment group compared with the control group (P<0.05). CZSG appeared to significantly delay the time of ARIE occurrence and reduce the duration compared with KFX (P<0.05). The scores of CM symptoms, KPS and weight were improved significantly in the treatment group compared with the control group (P<0.05). There were no blood routine and hepatorenal function abnormal or obvious side-effects in both groups. Hemoglobin was improved and neutrophil and interleukin 6 were decreased in both groups after 4-week treatment compared with before treatment (P<0.05), and there was no significant difference between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>CZSG can decrease the incidence and grade of ARIE, delay the time of occurrence, reduce duration and alleviate the damage of ARIE. It is safe and effective in the prevention and cure of ARIE.</p>
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Aged , Female , Humans , Male , Middle Aged , Acute Disease , Drugs, Chinese Herbal , Esophagitis , Drug Therapy , Medicine, Chinese Traditional , Methods , Neoplasms , Drug Therapy , Radiotherapy , Radiation Injuries , Drug Therapy , Radiotherapy Dosage , Treatment OutcomeABSTRACT
<p><b>BACKGROUND</b>Alemtuzumab has been used in organ transplantation and a variety of hematologic malignancies (especially for the treatment of B-cell chronic lymphocytic leukemia). However, serious infectious complications frequently occur after treatment. The reason for increased infections postalemtuzumab treatment is unknown at this stage. We explore the effect of alemtuzumab on intestinal intraepithelial lymphocytes (IELs) and intestinal barrier function in cynomolgus model to explain the reason of infection following alemtuzumab treatment.</p><p><b>METHODS</b>Twelve male cynomolguses were randomly assigned to either a treatment or control group. The treatment group received alemtuzumab (3 mg/kg, intravenous injection) while the control group received the same volume of physiological saline. Intestinal IELs were isolated from the control group and the treatment group (on day 9, 35, and 70 after treatment) for counting and flow cytometric analysis. Moreover, intestinal permeability was monitored by enzymatic spectrophotometric technique and enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>The numbers of IELs were decreased significantly on day 9 after treatment compared with the control group (0.35 ± 0.07 × 10 8 and 1.35 ± 0.09 × 10 8 , respectively; P < 0.05) and were not fully restored until day 70 after treatment. There were significant differences among four groups considering IELs subtypes. In addition, the proportion of apoptotic IELs after alemtuzumab treatment was significantly higher than in the control group (22.01 ± 3.67 and 6.01 ± 1.42, respectively; P < 0.05). Moreover, the concentration of D-lactate and endotoxin was also increased significantly on day 9 after treatment.</p><p><b>CONCLUSIONS</b>Alemtuzumab treatment depletes lymphocytes in the peripheral blood and intestine of cynomolgus model. The induction of apoptosis is an important mechanism of lymphocyte depletion after alemtuzumab treatment. Notably, intestinal barrier function may be disrupted after alemtuzumab treatment.</p>
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Animals , Male , Alemtuzumab , Antibodies, Monoclonal, Humanized , Therapeutic Uses , Apoptosis , Flow Cytometry , Intestines , Cell Biology , Lymphocytes , Macaca fascicularis , Microscopy, Electron, TransmissionABSTRACT
Objective To investigate the effect of transforming growth factor β1 (TGF-β1) on the expression of matrix metalloproteinase 9 (MMP-9),tissue inhibitor of metalloproteinase 1 (TIMP-1),nuclear factor kappa B(NF-κB) and the possible signalling pathways in human amniotic cells WISH.Methods The WISH cell line was cultured.WISH cells were added with TGF-β1 of different concentrations (0,2,10 and 20 ng/ml,respectively) for 24 hours.Then,reverse transcription (RT) PCR and western blotting were used to analyze the protein and mRNA expression of TIMP-1 and MMP-9; and the expression of NF-κB was analyzed by western blot.Results (1) The profile of TIMP-1 mRNA (0.413 ±0.036,0.623 ±0.058,1.392 ±0.124,1.387 ±0.102) in WISH cells elevated when the concentration of TGF-β1 increased (0,2,10,20 ng/ml).In accordance with TIMP-1 mRNA,the expression of TIMP-1 also elevated with the increase of TGF-β1 (0.357 ± 0.031,0.596 ± 0.048,1.243 ± 0.097 and 1.359 ± 0.121,respectively).And when 2,10 or 20 ng/ml of TGF-β1 was added,the TIMP-1 mRNA and protein were significantly higher than the TIMP-1 mRNA and protein when no TGF-β1 was added(P ＜ 0.05).(2)In contrast with TIMP-1,MMP-9 mRNA (1.325 ±0.056,0.987 ±0.081,0.610 ±0.034,0.347 ±0.023) in WISH cells decreased when the concentration of TGF-β1 increased (0,2,10,20 ng/ml).The MMP-9 protein (1.119 ±0.064,1.008 ±0.052,0.578 ±0.041,0.401 ±0.015) also decreased with the increase of TGF-β1.And when 2,10 or 20 ng/ml of TGF-β1 was added,the MMP-9 mRNA and protein were significantly lower than the MMP-9 mRNA and protein when no TGF-β1 was added (P ＜ 0.05).(3) The NF-κB protein (1.423 ±0.065,1.116 ± 0.045,0.796 ± 0.041,0.359 ± 0.021) was significandy reduced with the increase of TGF-β1 (0,2,10,20 ng/ml; P ＜ 0.05).Conclusions The mRNA and protein expression of TIMP-1 decreased when TGF-β1 was low in WISH cells,whereas those of MMP-9 elevated when TGF-β1 was low.The unbalance of TIMP-1 and MMP-9 was related to the pathology of the premature rupture of membrane.And the NF-κB singalling pathway might be an important mechanism in the regulation of TIMP-1 and MMP-9 system.
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The paper analysed the double-blind review result of Ph.D candidates' dissertation at Peking University People's Hospital.Rigor deficiency and inadequate knowledge about the research subjects were identified as the main problems.In the end some suggestions were proposed from two aspects,namely,full-process management of Ph.D training and supervisor-team construction.
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Improvement of the review of dissertation for doctoral degree is important for the training of qualified doctors.Current practice includes double-blind review and open review.This paper compares and analyses the outcome of the two kinds of reviews and found that double-blind review is more objective that the other(the mean of open review score is 96.39±2.069,the mean of double-blind review score is 85.18±6.635.P=0.001,P＜0.01).In the end some suggestions are proposed to improve the double-blind review system.
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Postgraduate administration is faced with new challenge in the affiliated clinical hospital because of the increasing quantity of postgraduates.The paper analyzed the characteristics of postgraduate administration and the status quo of information system construction in the affiliated clinical hospital and proposed the ideas of constructing information system for postgraduate administration from three aspects including system-frame,system-function and system-management.The purpose of the study was to provide reference for improving quality of postgraduate administration.
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Objective To evaluation the comprehensive acquired immunodeficiency syndrome (AIDS) intervention program conducting in men who have sex with men (MSM) population living in Inner Mongolia Autonomous region. Methods A comprehensive intervention program was carried out among MSM groups in Hohhot and Baotou City. Seven hundred and six and 767 MSM were enrolled for investigation through the snowball method during May 2008 and May to June 2009, respectively.At the same time, 5 mL intravenous blood sample was collected from each subject for human immunodeficiency virus (HIV) detection and intervention effect evaluation. Data were analyzed by x2test. Results After intervention, the awareness rate of HIV/AIDS knowledge increased from 70.7%(499/706) to 81.7%(627/767) (x2 =25. 004, P＜0.01 ). The rate of consistent condom use in the last six months increased from 38.0%(254/668) to 45.3% (346/764) (x2=8. 269, P＜0. 05). The percentage of subjects who had more than 5 different male sexual partner during the last 6 months significantly decreased from 42.8% to 24.6% (x2 = 55. 348, P＜0.01). The median number of sexual partners in MSM decreased from 3 in 2008 to 2 in 2009. The HIV infection rate was 1.7 % in both 2008 and 2009. Conclusion The comprehensive intervention program among MSM population shows positive influence after one year implementation, which is helpful for increasing HIV/AIDS awareness and safe sex behavior in this population.
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Cardiomyocytes can resist ischemia/reperfusion (I/R) injury through ischemic postconditioning (IPoC) which is repetitive ischemia induced during the onset of reperfusion. Myocardial ischemic preconditioning up-regulated protein 2 (MIP2) is a member of the WD-40 family proteins, we previously showed that MIP2 was up-regulated during ischemic preconditioning (IPC). As IPC and IPoC engaged similar molecular mechanisms in cardioprotection, this study aimed to elucidate whether MIP2 was up-regulated during IPoC and contributed to IPoC-mediated protection against I/R injury. The experiment was conducted on two models, an in vivo open chest rat coronary artery occlusion model and an in vitro model with H9c2 myogenic cells. In both models, 3 groups were constituted and randomly designated as the sham, I/R and IPoC/hypoxia postconditioning (HPoC) groups. In the IPoC group, after 45 min of ischemia, hearts were allowed three cycles of reperfusion/ischemia phases (each of 30 s duration) followed by reperfusion. In the HPoC group, after 6 h of hypoxia, H9c2 cells were subjected to three cycles of 10 minute reoxygenation and 10 minute hypoxia followed by reoxygenation. IPoC significantly reduced the infarct size, plasma level of Lactate dehydrogenase and creatine kinase MB in rats. 12 h after the reperfusion, MIP2 mRNA levels in the IPoC group were 10 folds that of the sham group and 1.4 folds that of the I/R group. Increased expression of MIP2 mRNA and attenuation of apoptosis were similarly observed in the HPoC group in the in vitro model. These effects were blunted by transfection with MIP2 siRNA in the H9c2 cells. This study demonstrated that IPoC induced protection was associated with increased expression of MIP2. Both MIP2 overexpression and MIP2 suppression can influence the IPoC induced protection.
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Animals , Male , Rats , Blotting, Western , Cell Hypoxia/genetics , Cell Line , Cell Survival/genetics , Flow Cytometry , Ischemic Preconditioning, Myocardial/methods , Myocytes, Cardiac/metabolism , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction , Reperfusion Injury/metabolismABSTRACT
Objective To evaluate the predictive value of 18F-fluorodeoxyglucose (FDG) and 18F-fluorothymidine(FLT) PET in monitoring the metastatic potential of human colorectal cancer (CRC).Methods Human CRC cell lines SW480 and SW620 were cultured and implanted into nude mice to create CRC models. Tumor growth,metastatic status and survival were assessed in CRC bearing mice. Uptake of 18F-FDG and 18F-FLT in SW480 and SW620 cells was detected In vitro at 0,30,60,90,120 min after incubation. PET images of both tracers were acquired for SW480 and SW620 tumor-bearing mice using the small animal PET at 60 min after tracer injection. Region of interest (ROI) was drawn using Image J software on reconstructed PET images. Immunocytochemistry and Western blot analysis of the tumor tissue were performed. The correlation between tracer uptake and tumor marker expression was evaluated using linear regression. Results Compared with SW620 tumor-bearing mice,SW480 induced tumor grew much faster ( t = - 3.332,P = 0.004),the tumor-bearing mice had more serious dyscrasia ( t = 2.240,P = 0.038 ),shorter survival and higher metastatic rate. In vitro study,the uptake of both 18F-FDG and 18F-FLT in SW620 cells was lower than that in SW480 cells. 18F-FLT uptake was higher than 18F-FDG uptake in both SW480 and SW620 cells. After incubation for 60 min,the uptake of 18F-FDG in SW480 and SW620 cells was ( 1.76 ± 0.87 )% and ( 1.14 ± 0.38 )%,respectively ( t = - 2.507,P = 0.021 ); while the uptake of 18F-FLT in SW480 and SW620 cells was (5.21 ± 1.60)% and (2.90 ± 1.82)%,respectively (t =3.497,P =0.002). In micro-PET study,the 18F-FDG radioactivity ratio of tumor to non-tumor (T/NT) in SW480 and SW620 tumors was 2.69 ± 0.98 and 3.09 ± 1.26 respectively (t =0.657,P =0.524); while T/NT of 18F-FLT in SW480 and SW620 tumors was 3.65 ±0.51 and 2.22 ±0.42 (t =6.491,P ＜0.001 ),respectively. In immunocytochemistry and western blot assay,heat shock protein(HSP) 27,Integrin β3,vascular endothelial growth factor receptor 2 ( VEGFR2 ) and Ki67 were all over expressed in two kinds of tumor cells with different intensities. HSP27 and Integrin β3 expression was higher in SW480 cells than that in SW620 cells. While VEGFR and Ki67 expression was lower in SW480 cells than that in SW620 cells. The uptake of 18F-FLT closely correlated with the expression of HSP27 ( r =0.924,P =0.004) and Integrin β3 (r=0.813,P =0.025). 18F-FDG uptake inversely correlated with the survival of tumor-bearing mice (r =0.500,P=0.017). Conclusions The uptake of 18F-FDGand 18F-FLT may reflect different biological characteritics of CRC. High 18F-FLT uptake in CRC on PET scan may predict high metastatic tendency.
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Objective To evaluate whether 18F-fluorothymidine(FLT) can be used to monitor early response to irradiation in colorectal cancer (CRC).Methods SW480 cells were cultured and irradiated with 0, 10, and 20 Gy.Twenty-four hours later, morphological changes, apoptosis, necrosis, proliferation,and cell cycle phases were observed.Uptake of 18F-FLT was measured in these tumors in vitro from 24 h to 72 h after irradiation.The one-way analysis of variance was used to analyze the data.Results Apoptotic and necrotic cells were detected 24 h after radiotherapy.SW480 cells proliferation was significantly delayed after irradiation in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide (MTI) assay.Cell cycle analysis showed that SW480 cells had a decreased fraction of cells in S phase( from 33.23% to 9.24%,then to 5.43% ) and an arrested fraction in G0-G1.After SW480 cells were cultured for60 min, the uptake of 18F-FLT was (5.21 ± 1.60) %; and 24 h after irradiation of 10 Gy, the uptake decreased significantly to (4.27±0.48)% (F=8.253, P=0.009).And 72 h after irradiation, the uptake further decreased significantly to (3.39 ± 0.59) % ( F = 36.715, P＜0.001 ).In tumor tissue, the uptake of 18F-FLT reduced significantly 72 h after radiotherapy (10 Gy:F = 12.388, P = 0.007; 20 Gy:F = 16.744, P = 0.004) and the attenuation degree increased with the radiation dose.Conclusion The uptake of 18F-FLT in SW480 cells or in CRC could reflect the changes of SW480 cells in proliferation, cell cycle re-distribution, cell apoptosis and necrosis.The results suggest that 18F-FLT may be used for monitoring early response to irradiation of CRC.
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<p><b>OBJECTIVE</b>To investigate the properties of passive film of three Cr alloys and to analyze their corrosion resistance in the artificial saliva with different NaCl mass fraction in vitro.</p><p><b>METHODS</b>Artificial saliva with 1%, 2% and 3% NaCl mass fraction was prepared. Cobalt-chromium alloy, nickel-chromium alloy and Ti-Ni-Cr alloy were employed as the working electrode in the artificial saliva. Semi-conductor properties of passive film on Cr alloy was analyzed by Mott-Schottky plots. In addition, the factors which affect the semi-conductive compact characteristic of the passive film was also discussed.</p><p><b>RESULTS</b>The passive film exhibits n-type semi-conductive characters. With the increasing of NaCl mass fraction, the carrier density of the Cr alloys also increased. The carrier density of the cobalt-chromium alloy, nickel-chromium alloy and Ti-Ni-Cr alloy are 3.71 x 10⁸, 2.34 x 10⁹, and 7.66 x 10⁹/cm³ respectively. This decreases its donor density and its film stability.</p><p><b>CONCLUSIONS</b>When exposed to saliva environment with high concentration of chlorine ion, corrosion resistance of the three types of Cr alloys decrease. This will reduce the service life of Cr alloy prosthesis.</p>