Objective To establish a sensitive ,reliable and convenient method for determination of total selenium(Se) in salt by HG-AFS. Methods The salt samples were dissolved and added hydrochloric acid (HCl),after heating by boiling water ,used HG-AFS to determinate Se. Results The linear range of the method was 0.5-400 ?g/L, The correlation coefficient was larger than 0.999 5, the recovery rates were 95.7%-102.8%. If 1 ml sample was collected, the detection limit was 0.08 ?g/L. Conclusion The method is sensitive, reliable, simple, less sample usage, and is an ideal method for determination of total selenium in salt.

Kinetic model analysis is a useful tool for understanding the regulation and control of cellular metabolism and thus offering a guideline for rational design of high efficiency cell factory. Based on previously published models and experimental measurement of enzyme kinetics data, we developed a kinetic model for the threonine biosynthesis pathway in Escherichia coli. This model integrates the central pathways that produce precursors, ATP and reducing power with the threonine biosynthesis pathway from aspartate. In contrast to the previous models, we considered the energy and reducing power balance rather than artificially set their concentrations. Metabolic control analysis of the model showed that enzymes PTS, G6PDH, HDH etc. have great flux control coefficients on the threonine biosynthesis flux. This indicates higher threonine synthesis flux could be achieved by overexpressing these enzymes.
Escherichia coli ; metabolism ; Industrial Microbiology ; Kinetics ; Metabolic Networks and Pathways ; Models, Biological ; Threonine ; biosynthesis

Objective To investigate the teaching effect of the PCMC-type (problem-originated clinical medical curriculum) pathology experiment course and clinical pathological conference (CPC) by using microscope digital system.Methods 384 undergraduates of second grade in clinical medicine major and imaging diagnosis major were chosen for the teaching reform project,all of whom were divided into experimental group (192) and control group (192),randomly,and they were taught by PCMC pathological experiment teaching and the traditional pathological experiment teaching separately.After the curriculum,statistic analysis of test score was used to analyze the teaching effect.SPSS 13.0 software diagram method was used to perform Levene variance analysis and t test to the achievement of two groups of students and the students' ability of self evaluation was investigated through questionnaire.Results The average score of the students in the experimental group (86.16 ± 3.28) in the theory exam was significantly higher than that of control group (75.63 ± 2.24) (P=0.000).And the average score of the students in the experimental group in experiment (27.10 ± 0.61) was significantly higher than that in control group (19.87 ± 0.25) (P=0.000).The questionnaire showed that compared with control group,the comprehensive ability of the students in the experimental group was obviously enhanced.Conclusion The PCMC pathology teaching is beneficial to improving the students' ability of linking theory with practice and enhancing their ability to analyze and solve problems,and obviously stimulate their interest in learning.It is worth promoting.

Objective To study the level and influencing factors of sense of coherence (SOC) among elderly patients with Parkinson's disease (PD).Method Totally 118 elderly patients with PD were investigated by a self-designed demographic questionnaire,sense of coherence-13 (SOC-13) and social support rating scale (SSRS),and to explore the level and influencing factors of SOC among the patients.Results The total score of SOC-13 was (52.27±9.30),and it was at a low level.Multiple regression analysis showed that educational level,severity of the disease,family economic status and social support were the influencing factors of SOC.Conclusion SOC of elderly patients with PD is at a low level,which is influenced by individual factors,nurses should take targeted measures to improve the patients' SOC status by the influencing factors.

Objective:To investigate the expression and relationship of differentiated embryo-chondrocyte expressed gene1(DEC1) and the signal tranducers and activator of transcription3 (STAT3) in gastric cancer tissues,and the significance of the two genes in gastric carcinogenesis. Methods:Immunohistochemistry method of SP was adopted to discover the expression of DEC1 and STAT3 in 59 gastric cancer tissues,19 normal tissues distant from tumor were regarded as control. Results:The positive expression rate of DEC1 in gastric cancer tissues was 71.2%(42/59),which was significantly higher than that in normal para-cancer tissues(26.3%)(P0.05). STAT3 expression was associated with TNM staging,invasion depth,lymph node involvement and tumor grade (P0.05). Conclusions:DEC1 expression was higher in gastric cancer tissues than that in normal para-cancer tissues distant from tumor,and was correlated with STAT3 in gastric cancer. DEC1 and STAT3 are both transcription factors,therefore the co-activation of DEC1 and STAT3 may play an important role in the carcinogenesis and development of gastric cancer.

Objective To investigate the effect of simvastatin on endothelial cell function in a rat model of sepsis. Methods Ninety-six pathogen-free female Wistar rats aged 4 months weighing 200-250 g were randomly divided into 3 groups (n = 32 each): group sham operation (group Ⅰ ); group sepsis (group Ⅱ )and group simvastatin + sepsis(group Ⅲ ) . Sepsis was induced by cecal ligation and puncture (CLP). In group Ⅲ simvastatin 20 mg/kg was given via a gastric tube once a day for 2 weeks. Blood samples were taken from carotid artery at 3,6, 24 and 48 h ( n = 8 at each time point) for WBC count and measurement of serum E-selectin concentration (by ELISA) . Results CLP significantly increased WBC count and serum E-selectin concentration in group Ⅱ as compared with group Ⅰ . The peak values were reached at 6 h after operation. Simvastatin pretreatment attenuated the sepsis-induced increase in WBC count and serum E-selectin concentration in group Ⅲ. Conclusion Protection of endothelial cell function is involved in the mechanism of treatment of sepsis with simvastatin.

OBJECTIVE: To investigate osteopontin (OPN) expression in plasma and tissue of patients with layngeal squamous cell carcinoma and analyze its role in invasion, metastasis, and clinical significance in laryngeal quamous cell carcinoma. METHOD: Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect expression of OPN in plasma and tissue of 60 cases of laryngeal squamous cell carcinoma, 20 cases of adjacent normal laryngeal tissue and 20 cases of plasma from healthy subjects. RESULT: The expression of plasma OPN was closely correlated with clinical stage and cervical lymphatic metastasis in laryngeal squamous cell carcinoma (P < 0.05), but no significant correlation with the tumor location, pathological grade, gender and age (P > 0.05). The expression of OPN increased in plasma during cancer development: laryngeal squamous cell carcinoma (38.089 ± 9.225) ng/ml, healthy subjects (18.563 ± 9.308) ng/ml. There was a significant difference between the groups (P < 0.05). The expression of OPN in tissue was closely correlated with clinical stage (P < 0.05), pathological grade (P < 0.05) and cervical lymphatic metastasis (P < 0.05) in laryngeal squamous cell carcinoma adjacent atypical hyperplastic epithelium and carcinoma. The expression of OPN increased in tissue during cancer development: laryngeal squamous cell carcinoma (56.67%), adjacent normal laryngeal tissue (15.00%). There was a significant difference between the groups (P < 0.05). Elevated expression of plasma OPN is positively correlated with the expression of OPN in tissue in laryngeal squamous cell carcinoma patients (r = 0. 871, P < 0.05). CONCLUSION OPN plays an important role in the infiltration, metastasis and carcinogenesis in laryngeal squamous cell carcinoma. Combination of serum OPN, tissue OPN detection can be used as diagnostic and surveillance indicators for laryngeal squamous cell carcinoma infiltration and metastasis.
Carcinoma, Squamous Cell ; metabolism ; pathology ; Case-Control Studies ; Enzyme-Linked Immunosorbent Assay ; Head and Neck Neoplasms ; metabolism ; pathology ; Humans ; Hyperplasia ; pathology ; Immunohistochemistry ; Laryngeal Neoplasms ; metabolism ; pathology ; Larynx ; pathology ; Lymphatic Metastasis ; Neck ; Osteopontin ; metabolism ; Squamous Cell Carcinoma of Head and Neck

Objective To investigate certain risk factors for and their impact on abnormal liver function in middle-aged and elderly adults.Methods A case-control study was constructed based on the SAGE cohort of 8642 registered residents aged 50 years or over in Shanghai.Of them,137 individuals with abnormal liver function,defined as aspartate transaminase (AST)＞ 40 U/L or alanine aminotransferase (ALT)＞ 40 U/L,were randomly selected as the observation group,while 411 healthy controls were 3 ∶ 1 matched with the cases in the observation group by gender and age (1 year).Face-to-face administered questionnaires and physical examinations were conducted and serum samples were tested for ALT,AST,glucose (GLU),total cholesterol (TC),triglycreide (TG),hepatitis B surface antigen (HbsAg) and anti-hepatitis C virus antibody (anti-HCV Ab).Chi square test and rank sum test were used for single factor analysis,and logistic regression analysis was used for multiple factors.Results The prevalence of HBsAg positive patients was 12.4 ％ (68/548) Univariate analysis showed that hepatitis virus infection and body mass index (BMI) were associated with abnormal liver function (both P＜0.000).Multivariate logistic regression analysis showed that hepatitis virus infection (OR=1.85,95％ CI:1.04 3.29,P-0.036) and obesity (OR=3.60,95％CI:1.92-6.73,P＜0.001) increased the risk of abnormal liver function,whereas chronic medication (OR=0.51,95％ CI:0.32-0.80,P =0.004) decreased the risk of abnormal liver function.Conclusions Among the study population,hepatitis virus infection and obesity are risk factors for abnormal liver function in middle-aged and elderly people.After adjustment for potential confounders,chronic medication is negatively correlated with abnormal liver function and may be a protective factor for liver function.

Objective To establish a rat model of tympanosclerosis(TS) by myringotomy and inoculation of streptococcus pneummoniae, and to observe the morphological change in the tympanic membrane (TM) and middle ear mucous.Methods Forty Sprague-Dawley rats were randomly divided into two groups (n=20/group) and then ten in each group were chosen to serve as the control and the other ten were set up for the TS model.Group A (myringotomy): myringotomy was performed on the bilateral TMs of all rats except the control group.Group B (bacterial inoculation): streptococcus pneumoniae was inoculated into the bilateral middle ear cavity of all rats except the control group.The condition of the TMs and the middle ears in the two groups were respectively examined at 2 weeks after myringotomy and at the five time points (1 week, 2 weeks, 4 weeks, 6 weeks, and 8 weeks) after bacterial inoculation.Then the rats were decapitated and the morphological changes were observed by hematoxylin and eosin staining.Results One rat in group B died two weeks after the inoculation.In the two experimental groups, the calcifications were observed in 70%of the TMs (14/20) in group A and in 33.33%of the TMs (6/18) at 8 weeks in group B.At the same time, the inflammatory infiltration and hyaline degeneration markedly appeared in the tympanic membrane and middle ear mucous membrane.In the two control groups, neither morphological changes nor calcifications occurred.Conclusion The current study indicated that the animal model of TS was successfully accomplished by myringotomy and inoculation of streptococcus pneummoniae, and their morphological changes were basically consistent.However, the method of myringotomy is easier to use and can obtain a higher modeling rate in a relatively short time.

Objective To evaluate the fiber altering and clinical relationship in patients with occipital and temporal lobe cerebral infarction with DTI.Methods Fifty patients suffering from cerebral stroke were analyzed with conventional MRI,DWI and DTI. The fibers of visual pathway were depicted ,and their fractional anisotropy (FA),apparent diffusion coefficient (ADC),isotropic im-age (Iso)and T2-weighted trace were measured and analyzed.Results Regions of interest (ROIs)were placed in infarction and nor-mal contralateral tissue for tracking the visual pathways.The different parameters were measured.FA is useful to differentiate hy-per-acute stroke from acute and sub-acute stroke.FA values increased slightly in hyper-acute and decreased in acute,sub-acute and chronic phase.The values of ADC in infarction regions in hyper-acute,acute and sub-acute phases were lower than those of the con-tralateral tissue.Iso and T2-weighted trace increased in acute phase and decreased in chronic phase.DTT was used to show the way and chang of visual pathway.Conclusion DTI could track the fiber of visual pathway,and depict the fiber of infarction zone.DTT could be used in evaluating the prognosis of patients.