Quantitative characterization of cell physiological state based on dynamical cell mechanics for drug efficacy indication / 药物分析学报

Cell mechanics is essential to cell development and function,and its dynamics evolution reflects the physiological state of cells.Here,we investigate the dynamical mechanical properties of single cells under various drug conditions,and present two mathematical approaches to quantitatively character-izing the cell physiological state.It is demonstrated that the cellular mechanical properties upon the drug action increase over time and tend to saturate,and can be mathematically characterized by a linear time-invariant dynamical model.It is shown that the transition matrices of dynamical cell systems signifi-cantly improve the classification accuracies of the cells under different drug actions.Furthermore,it is revealed that there exists a positive linear correlation between the cytoskeleton density and the cellular mechanical properties,and the physiological state of a cell in terms of its cytoskeleton density can be predicted from its mechanical properties by a linear regression model.This study builds a relationship between the cellular mechanical properties and the cellular physiological state,adding information for evaluating drug efficacy.

An animal model of bladder reconstruction by autologous peritoneum transplantation / 中华外科杂志

Objective@#To establish experimental porcine model of reconstruction the neobladder by ileal seromuscular with transplantation of autologous peritoneum.@*Methods@#This was an animal experiment carried out from January to April 2018 at animal center of Guizhou Medical University. Randomly 6 experimental female porcines were chosen, and their body weight was 28 to 33 kg. By intravenous anesthesia, the transplantation of autologous peritoneum for bladder reconstruction operation was carried out by transplanting the peritoneum onto an ileum segment which mucosa and submucosa had been removed. These flaps were used to mend and reconstruct the neobladder by suturing with edge of the detective bladder. After removal of ureteral catheters and balloon catheter at day 5 and day 7 respectively, voiding behavior was monitored, and animals were euthanized at week 12 for routine pathology, immunohistochemistry, and electron microscopic examinations.@*Results@#Six porcines underwent reconstruction, but no one lost to complications such as peritonitis, ileus and urinary fistula. Voiding behavior was normal, and urine was clear in all animals after removal of catheters. At autopsy, reconstructed bladders were healthy. Pathological examination showed the part of reconstruction had been covered by continuous urothelium while the peritoneum disappeared and showed no ileal mucosa regrowth and residual. Scanning electron microscope showed that the transitional cells of neobladder were complete and orderly, and urothelium around suture border was continuous and no malposition.@*Conclusion@#In this experimental porcine model, reconstruction bladder by autologous peritoneum and ileal seromuscular flaps is an ideal approach.

Relationship between selenium and the risk for oral cancer: a case-control study / 中华流行病学杂志

Objective@#To explore the relationship between selenium and the risk for oral cancer.@*Methods@#We performed a case-control study in 325 cases of newly diagnosed primary oral cancer from the First Affiliated Hospital of Fujian Medical University and 650 controls from the same hospital and community. Unconditional logistic regression and stratification analyses were used to explore the association between selenium and oral cancer. Adjusted OR and corresponding 95%CI were calculated. The analyses on multiple interactions between selenium and smoking or drinking status, and fruit or fish intake frequencies were conducted.@*Results@#The level of serum selenium was 112.42 (80.98-145.06) μg/L in the case group, which was lower than 164.85 (144.44-188.53) μg/L in control group, the difference was statistical significant (P<0.01). There was a negative correlation between serum selenium level and the risk for oral cancer regardless of smoking and drinking status, and fruits and fish intake frequencies (P<0.05). There were multiple interactions between serum selenium level and smoking or drinking status, and fruit and fish intakes.@*Conclusions@#The high level of serum selenium is a protective factor for the incidence of oral cancer, and serum selenium has multiple interactions with smoking or drinking status, and fruit and fish intakes. Therefore, reducing tobacco use and alcohol consumption and increasing the intakes of fruit and fish can reduce the risk for oral cancer to some extent.

Association of single nucleotide polymorphisms of TBX5 gene and environmental exposure index with susceptibility to oral cancer / 中华预防医学杂志

Objective@#To explore the association of TBX5 polymorphisms and environmental exposure index with susceptibility to oral cancer.@*Methods@#A case-control study was conducted to collect 300 oral cancer patients hospitalized in the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Fujian Medical University from September 2010 to December 2016. A total of 445 non-tumor patients were selected as the control group. Questionnaires were used to collect the information of all subjects and 5 ml peripheral blood was collected to detect single nucleotide polymorphisms (SNPs) of the rs10492336 locus of TBX5 gene. According to the environmental exposure index score, subjects were divided into two groups, low risk group (0-2.31) and high risk group (2.32-11.76). To analyze the association of TBX5 gene rs10492336 SNPs, environmental exposure index and oral cancer and its interactions.@*Results@#The age of all subjects in the case group and control group were (56.19±13.10) years and (54.56±12.48) years old. Compared with CC genotype, the OR (95%CI) values of the co-dominant genetic model AC genotype and the dominant genetic model AC+AA genotype were 0.69 (0.49-0.98) and 0.70 (0.51-0.97), respectively. Compared with the low risk group, the OR (95%CI) risk of oral cancer in the high risk group was 3.72 (2.55-5.43). The results of gene-environment interaction analysis showed that compared with the group with CC genotype and high risk of environmental exposure index, the OR (95%CI) value of oral cancer in the group with AC+AA genotype and low risk of environmental exposure index was 0.18(0.10-0.31). Furthermore there was a multiplicative interaction between rs10492336 SNPs and environmental exposure index (β=-0.405, P<0.001).@*Conclusion@#This study suggests that the TBX5 gene rs10492336 SNPs and environmental exposure index were associated with oral cancer. And there was a multiplication interaction between rs10492336 SNPs and environmental exposure index.

A novel prognostic index for oral cancer in Fujian province / 中华流行病学杂志

Objective To explore the survival factors and construct a prognostic index (PI) for oral squamous cell carcinoma (OSCC).Methods From January 2004 to June 2016,a total of 634 patients with pathologically confirmed OSCC were recruited in a hospital of Fujian.The clinical and follow-up data of all the patients with pathologically confirmed OSCC were collected to identify the factors influencing the prognosis of OSCC.All the patients were randomly divided into two groups:modeling group (modeling dataset,n =318) and validation group (validation dataset,n =316).Randomization was carried out by using computer-generated random numbers.In the modeling dataset,survival rates were calculated using Kaplan-Meier method and compared using the log-rank test.Cox regression model was used to estimate the hazard ratio (HRs) and 95％ confidence intervals (CIs) of prognosis factors.An PI for OSCC patients prognostic prediction model was developed based onβ value of each significant variable obtained from the multivariate Cox regression model.Using the tertile analysis,patients were divided into high-risk group,moderate-risk group,and low-risk group according to the PI,the Akaike information criterion (AIC) and Harrell's c-statistic (C index) were used to evaluated the model's predictability.Results Results from the multivariate Cox regression model indicated that aged ≥55 years (HR=2.22,95％ CI:1.45-3.39),poor oral hygiene (HR=2.12,95％ CI:1.27-3.54),first diagnosis of lymph node metastasis (HR=5.78,95％CI:3.60-9.27),TNM stage Ⅲ-Ⅳ (stage Ⅰ as reference) (HR=2.43,95％CI:1.10-5.37) and poor differentiation (well differentiation as reference) (HR=2.53,95％CI:1.60-4.01) were the risk factors influencing the prognosis of OSCC.The PI model had a high predictability in modeling group and validation group (AIC and C index were 1 205.80,0.700 2 and 1 150.47,0.737 3).Conclusion Age,poor oral hygiene,first diagnosis of lymph node metastasis,TNM stage and histological grade were factors associated with the prognosis of OSCC,and the PI model has a certain significance in the clinical treatment of OSCC.

A novel prognostic index for oral cancer in Fujian province / 中华流行病学杂志

Objective To explore the survival factors and construct a prognostic index (PI) for oral squamous cell carcinoma (OSCC).Methods From January 2004 to June 2016,a total of 634 patients with pathologically confirmed OSCC were recruited in a hospital of Fujian.The clinical and follow-up data of all the patients with pathologically confirmed OSCC were collected to identify the factors influencing the prognosis of OSCC.All the patients were randomly divided into two groups:modeling group (modeling dataset,n =318) and validation group (validation dataset,n =316).Randomization was carried out by using computer-generated random numbers.In the modeling dataset,survival rates were calculated using Kaplan-Meier method and compared using the log-rank test.Cox regression model was used to estimate the hazard ratio (HRs) and 95％ confidence intervals (CIs) of prognosis factors.An PI for OSCC patients prognostic prediction model was developed based onβ value of each significant variable obtained from the multivariate Cox regression model.Using the tertile analysis,patients were divided into high-risk group,moderate-risk group,and low-risk group according to the PI,the Akaike information criterion (AIC) and Harrell's c-statistic (C index) were used to evaluated the model's predictability.Results Results from the multivariate Cox regression model indicated that aged ≥55 years (HR=2.22,95％ CI:1.45-3.39),poor oral hygiene (HR=2.12,95％ CI:1.27-3.54),first diagnosis of lymph node metastasis (HR=5.78,95％CI:3.60-9.27),TNM stage Ⅲ-Ⅳ (stage Ⅰ as reference) (HR=2.43,95％CI:1.10-5.37) and poor differentiation (well differentiation as reference) (HR=2.53,95％CI:1.60-4.01) were the risk factors influencing the prognosis of OSCC.The PI model had a high predictability in modeling group and validation group (AIC and C index were 1 205.80,0.700 2 and 1 150.47,0.737 3).Conclusion Age,poor oral hygiene,first diagnosis of lymph node metastasis,TNM stage and histological grade were factors associated with the prognosis of OSCC,and the PI model has a certain significance in the clinical treatment of OSCC.

Pickled food, fish, seafood intakes and oral squamous cell carcinoma: a case-control study / 中华预防医学杂志

Objective@#To investigate the effects between fish, seafood and pickled food intakes on oral squamous cell carcinoma (OSCC).@*Methods@#A case-control study was carried out in Fujian area during September 2010 to December 2016, in which 604 newly diagnosed primary OSCC cases confirmed by pathological diagnosis were collected from hospital and 1 343 control subjects were enrolled from community and healthy hospital population. Demographic data, history of smoking drinking and tea drinking, oral hygiene status and dietary behaviors (fish, seafood and pickled food intakes) were collected by in-person interviews using a standard questionnaire.Using unconditional logistic regression to estimate adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to assess the effects of fish, seafood and pickled food intakes on OSCC. Analysis stratified by smoking, alcohol drinking and bad prosthesis to explore the possible difference in association between subgroups. Multiplicative interactions and additive interactions between fish and bad prosthesis, seafood and alcohol drinking, pickled food and bad prosthesis were assessed by unconditional logistic regression, relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S).@*Results@#The average age of case group and control group were separately (58.69±13.92) years old and (59.27±11.37) years old (χ2=4.75, P=0.191). The people whose fish and seafood intakes ≥3 times/week had the lower risk of OSCC, the adjusted OR (95%CI) values were 0.63 (0.52-0.77) and 0.51 (0.41-0.64); The stratified analysis indicated that the people having bad prosthesis had the lower risk of OSCC if they eating fish ≥3 times/week, and the adjusted OR (95%CI) values was 0.53 (0.39-0.71); the people having bad prosthesis had the higher risk of OSCC if they eating pickled food ≥3 times/week, the adjusted OR (95%CI) values was 1.37 (1.02-1.88). Regularly eating seafood can decrease the risk of OSCC for non-smokers, smokers, non-drinkers, drinkers, people without bad prosthesis and had bad prosthesis, the adjusted OR (95%CI) values were 0.49 (0.36-0.68), 0.52 (0.37-0.73), 0.41 (0.31-0.55), 0.77 (0.51-0.96), 0.49 (0.36-0.67), 0.59 (0.42-0.83). Crossover analysis showed fish and bad prosthesis exist multiplication interaction relationship (adjusted OR=0.66, 95%CI: 0.44-0.97) and additional interaction relationship (RERI=-0.81, 95%CI:-1.43--0.19; AP=-0.76, 95%CI:-1.35--0.17; S=0.08, 95%CI: 0.01-0.98); pickled food and bad prosthesis exist multiplication interaction relationship (adjusted OR=1.63, 95%CI: 1.06-2.51) and addition interaction relationship (RERI=0.65, 95%CI:0.08-1.22; AP=0.36, 95%CI:0.10-0.62; S=5.19, 95%CI:1.32-54.49).@*Conclusion@#Reducing the consumption of pickled food, quitting smoking and limiting alcohol consumption, and regularly eating fish and seafood can prevent the occurrence of OSCC.

A case-control study: association between oral hygiene and oral cancer in non-smoking and non-drinking women / 中华预防医学杂志

Objective@#To evaluate the influence of oral hygiene on risk of oral cancer in non-smoking and non-drinking women.@*Methods@#From September 2010 to February 2016, 242 non-smoking and non-drinking female patients with pathologically confirmed oral cancer were recruited in a hospital of Fuzhou, and another 856 non-smoking and non-drinking healthy women from health examination center in the same hospital were selected as control group. Five oral hygiene related variables including the frequency of teeth brushing, number of teeth lost, poor prosthesis, regular dental visits and recurrent dental ulceration were used to develop oral hygiene index model. Unconditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95%CI). The area under the receiver operating characteristic curve (AUROC) was used to evaluate the predictability of the oral hygiene index model. Multivariate logistic regression model was used to analyze the association between oral hygiene index and the incidence of oral cancer.@*Results@#Teeth brushing <2 twice daily, teeth lost ≥5, poor prosthesis, no regular dental visits, recurrent dental ulceration were risk factors for the incidence of oral cancer in non-smoking and non-drinking women, the corresponding OR (95%CI) were 1.50 (1.08-2.09), 1.81 (1.15-2.85), 1.51 (1.03-2.23), 1.73 (1.15-2.59), 7.30 (4.00-13.30), respectively. The AUROC of the oral hygiene index model was 0.705 9, indicating a high predictability. Multivariate logistic regression showed that the oral hygiene index was associated with risk of oral cancer. The higher the score, the higher risk was observed. The corresponding OR (95%CI) of oral hygiene index scores (score 1, score 2, score 3, score 4-5) were 2.51 (0.84-7.53), 4.68 (1.59-13.71), 6.47 (2.18-19.25), 15.29 (5.08-45.99), respectively.@*Conclusion@#Oral hygiene could influence the incidence of oral cancer in non-smoking and non-drinking women, and oral hygiene index has a certain significance in assessing the combined effects of oral hygiene.

Selective Recognition of Ciprofloxacin from Aqueous Solution by Molecularly Imprinted Polymers Based on Magnetic Illite / 分析化学

The magnetic Illite ( MILT) was firstly prepared by an effective polyol-medium solvothermal method. Based on these 3-( methacryloyloxy) propyl trimethoxysilane ( MILT-MPS), magnetic molecularly imprinted polymers (MMIPs) were further synthesized via atom transfer radical polymerization in a mixture solution of methanol and deionized water. The as-prepared MMIIPs were characterized by FT-IR, TEM), XRD, TGA and vibrating sample magnetometer (VSM), and the results indicated that the MMIIPs exhibited magnetic sensitivity ( Ms =3. 866 emu / g ), thermal stability and a larger specific surface area (109. 58 m2 / g). The batch mode adsorption studies were carried out to investigate the recognition specificity and selective capacity. The Langmuir isotherm model was fitted to the equilibrium data, and the monolayer adsorption capacity of MMIPs at 25℃ was 86. 58 mg / g. The selective recognition experiments demonstrated high affinity and selectivity of MMIPs towards ciprofloxacin ( CIP) over competitive compounds. Combined with high performance liquid chromatographic analysis technology, the prepared MMIIPs were successfully applied to extract and enrich trace CIP in environmental samples with the CIP recoveries from 93. 4% to 98. 3% and the limit of detection of 0. 01 mg / L.

Application value of quantitative measurements based on cross-sectional MR images for patellofemoral instability / 中华放射学杂志

Objective To explore the value of 6 commonly-used quantitative measures on crosssectional MR images to diagnose the patellofemoral instability.Methods Clinical data of 32 patients with patellofemoral instability(34 knees) confirmed by arthroscopy surgery were retrospective analyzed.Knee MR imaging at full extension of the knee was performed in them.Their MR images were compared with those of 23 asymptomatic volunteers.Trochlear facet asymmetry,lateral trochlear inclination,trochlear depth,patellar tilt angle,lateral patellar displacement,and tibial tuberosity-trochlear groove distance(TTTG) were measured in transverse fat-suppressed turbo spin-echo proton density-weighted MR images.Independent sample t test or Mann-Whitney U test were used to compare the differences of these measurements.ROC was used to calculate the area under curve(AUC) and to define the diagnostic threshold value of each measure.Results Trochlear facet asymmetry,lateral trochlear inclination,and trochlear depth in patients were 45.0％±9.2％,10.9°±5.0° and(3.7±1.3) mm,while these measurements were 68.0％±10.5％,21.1°±3.4° and (6.3 ± 1.0) mm in volunteers.These measures were significantly lower in patients than those in volunteers (t values were 10.123,10.862 and 9.835,P＜0.01).Patellar tilt angle and lateral patellar displacement were significantly higher in patients than those in volunteers(24.8°±9.0° vs.12.3°±5.2°,7.36 mm vs.-3.93 mm,t value and Z value were-7.657 and-6.953,P＜0.01).TTTG showed no significant difference between the 2 groups(P=0.798).AUC of trochlear facet asymmetry,lateral trochlear inclination,trochlear depth,patellar tilt angle,and lateral patellar displacement were 0.957,0.957,0.947,0.921 and 0.961,respectively.The recommended diagnostic threshold values for these 5 measures were＜55％,＜15°,＜5 mm,＞17° and＜3 mm,respectively.The sensitivity for these five measurements were 91.2％ (31/34),85.3％ (29/34),91.2％ (31/34),82.4％ (28/34) and 79.4％ (27/34),respectively.The specificity for these five measures were 91.3％ (42/46),97.8％ (45/46),89.1％ (41/46),89.1％ (41/46) and 100.0％ (46/46),respectively.AUC of TTTG was 0.520.Conclusions At full extension of the knee,trochlear facet asymmetry,lateral trochlear inclination,trochlear depth,patellar tilt angle and lateral patellar displacement are all effective in evaluating patellofemoral instability.The diagnostic value of TTTG is relatively poor.

Clinical characteristics and treatment responses of X-linked thrombocytopenia / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the clinical and molecular characteristics of patients with X-linked thrombocytopenia (XLT) and their responsiveness to treatment with various doses of corticosteroids or intravenous immunoglobulin (IVIG) separately.</p><p><b>METHOD</b>Data from 15 XLT patients who were hospitalized in Children's Hospital Affiliated to Chongqing Medical University from March 2010 to July 2014 were analyzed retrospectively, including clinical manifestations, scores, peripheral blood, immunological functions, responses to IVIG and steroid treatment with various doses and duration.</p><p><b>RESULT</b>All 15 XLT patients met the inclusion criteria and showed microthrombocytopenia with or without mild-to-moderate eczema or minor infections. Platelet counts ranged from (8-80) × 10⁹/L. The platelet volume value ranged between 5.6 and 10.9 fl (normal range: 9.4-12.5 fl). Raised serum IgG was found in 5 cases, while low serum IgG was found in 2 cases. WAS gene analysis revealed missense mutations in 14 patients, including 4 hotspots (V75M, R86C, R86H, R86L) and 1 novel mutation (Y107C). Flow cytometer analysis of 13 patients showed various amounts of WAS protein (WASP) expression, 2 patients had normal amounts of WASP expression, 5 had reduced amounts, and 6 had absent WASP expression. Their responses to individual steroid and IVIG treatment with various doses and duration were also reviewed. Fourteen patients who were misdiagnosed as immune thrombocytopenic purpura at first received 28 courses of steroids and (or) 47 courses of IVIG treatment. The post-treatment platelet counts of 1 000-2 000 mg/(kg × d) IVIG(25 courses) at 2-7 d and 8-14 d time points were (60 ± 10) × 10⁹/L and (41 ± 7) × 10⁹/L, which indicate a significantly better responsiveness than those by [(31 ± 7) × 10⁹/L, (21 ± 2) × 10⁹/L] of 400-500 mg/(kg·d) IVIG(22 courses) (Z = -4.419, -1.592;P = 0.002,0.011). However, there were no significant differences between the responsiveness of 3 doses [1-2 mg/(kg·d)(8 courses), 3-6 mg/(kg·d) (11 courses) and 20-30 mg/(kg × d)(9 courses)] of steroids (F = 0.387,0.252;P = 0.980,0.761) at 2-7 d and 8-14 d time points. The platelet counts gradually decreased to the primary level at 15-30 d after any doses of steroids and (or) IVIG treatment. The effective rate of 1 000-2 000 mg/(kg × d) IVIG treatment was 18/25, which was significantly higher than that (2/22) of 400-500 mg/(kg × d) (χ² = 9.836, P = 0.008). The effective rate of 20-30 mg/(kg × d) steroids treatment (7/9) was relatively higher than 1-2 mg/(kg × d) (4/8) and 3-6 mg/(kg × d) (6/11) with no significant difference (χ⁹ = 3.235, P = 0.581). After the treatment with steroids and /or IVIG 14 cases with hemorrhage were all improved.</p><p><b>CONCLUSION</b>The clinical characteristics of X-linked thrombocytopenia were microthrombocytopenia with or without mild-to-moderate eczema or minor infections. WAS gene and WASP analysis were diagnostic methods. There were no significant differences between the responsiveness of 3 doses of steroids; 1 000-2 000 mg/(kg·d) IVIG had a significantly better responsiveness. However, IVIG and steroids with any dose and duration may only transiently increase peripheral platelet level of XLT patients.</p>

Effects of dehydroepiandrosterone on memory ability and cholinergic activity of the aged rat brain / 中华老年医学杂志

Objective To explore the effects of dehydroepiandrosterone (DHEA) on learning and memory ability and activities of choline acetyltransferase (ChAT),acetylcholinesterase (AchE),acetylcholine (Ach) in the frontal,temporal,hippocampal area of the aged rat.Methods Forty 24-month-old male SD rats were randomly divided into 4 groups (n=10,each group):control group,solvent group (intraperitoneal injection with equal volumes of DMSO),low-dose group (intraperitoneal injection with equal volumes of DHEA,1 mg/kg),and high-dose group (intraperitoneal injection with equal volumes of DHEA,5 mg/kg).The activities of ChAT,AchE,and Ach were measured by enzyme linked immunosorbent assay (ELISA) method.Learning and memory ability was detected by Morris water maze test.Results The levels of ChAT in frontal,temporal and hippocampal area were (118.5±1.3) U/mg,(120.6±1.5) U/mg,(130.8±1.5) U/mg,respectively in control group,(i39.5±1.6) U/mg,(137.4±1.4) U/mg,(141.46±1.9) U/mg,respectively in high-dose group,(131.8±1.9) U/mg,(132.4±1.2) U/mg,(139.9±1.3) U/mg,respectively in low-dose group.The levels of AchE in frontal,temporal and hippocampal area were (0.5±0.0) U/mg,(0.4±0.0) U/mg,(0.5±0.0) U/mg,respectively in control group,(0.4±0.0) U/mg,(0.4±0.0) U/mg,(0.4±0.0) U/mg,respectively in high-dose group,and (0.4±0.0) U/mg,(0.4±0.0) U/mg,(0.4±0.0) U/mg,respectively in low-dose group,and (0.5±0.0)U/mg.The Ach levels in frontal,temporal and hippocampal area were (26.0±0.8) U/mg,(24.5±1.4) U/mg,(30.1±0.8) U/mg respectively in control group,(28.7±0.9) U/mg,(28.9±1.3) U/mg,(35.9±1.4) U/mg,respectively in high-dose group,and (27.6±0.1) U/mg,(28.0±1.1) U/mg,(34.2± 1.0) U/mg,rcspectively in low dose group.The activities of ChAT in frontal,temporal and hippocampal area were higher in DHEA treatment group than in control group (P＜0.05).The activities of AchE in frontal,temporal and hippocampal area were much lower in DHEA treatment group than in control group (P＜ 0.05).The Ach levels in frontal,temporal and hippocampal area were much higher in DHEA treatment group than in control group (P＜0.05).There were significant differences in the activities of ChAT and AchE and Ach levels between low-dose group and high-dose group (P＜0.05).Compared with control group,the activities of ChAT and AchE and Ach levels had no significant differences in solvent group (P＞0.05).The escape latency was shorter in low-dose group and high-dose group than in control group (P＜0.05,P＜0.01,respectively),and there was a significant difference in escape latency between low-dose group and high dose group (P＜ 0.05).Conclusions DHEA administration can significantly increase the activity of cholinergic system,and improve the learning and memory ability in aged SD rats.

Evaluation of metal artifacts formation and its influencing factors of spinal metal implants using multi-slice spiral CT / 中国组织工程研究

Transpedicular screw and rod internal fixation system is the common implants in spinal surgery. Multi-slice spiral CT and magnetic resonance imaging can generate section image, become routine imaging modality in the assessment of the postoperative spinal patients. Magnetic resonance imaging can evaluate the bone marrow and soft tissue, which is the first choice for examination. However, to the patients with metal implants, the existed metal artifacts can decrease the imaging quality. Therefore, multi-slice spiral CT is an important evaluation method for inserted material, os integumentale and anatomy. This article reviewed the production mechanism of metal-related artifacts, influencing factors and decreasing technique.