This paper reports a method for direct determination of ascorbic acid by ultra-violet differential spectrometry and its application to analysis of ascorbic acid contents in vegetables, fruits and tablets. All the four (1st to 4th) derivatives of spectrometry were available for determination, and the better results were obtained from the 2nd derivative spectrometry. The results showed that this method was simple, rapid and accurate.

Carcinoma, Neuroendocrine ; pathology ; Carcinoma, Squamous Cell ; pathology ; Humans ; Neoplasm Staging ; Thymoma ; classification ; pathology ; Thymus Neoplasms ; classification ; pathology ; World Health Organization

Actins ; metabolism ; Adult ; Brain Neoplasms ; metabolism ; pathology ; surgery ; Desmin ; metabolism ; Diagnosis, Differential ; Dura Mater ; chemistry ; pathology ; Female ; Granuloma, Plasma Cell ; metabolism ; pathology ; surgery ; Humans ; Immunohistochemistry ; Meningeal Neoplasms ; pathology ; Meningioma ; pathology ; Neoplasms, Muscle Tissue ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

In this paper we analyzed examination results of the Beijing Community Dentistry Professional Post Assessment and related factors, also discussed the measures for improving the quality of the post assessment. In 325 examinees 244 passed with a pass rate of 75.1%. There significant differences among examinees, educational background and academic training were most influential

Methamphetamine is a powerful stimulant of amphetamine type in the central nervous system (CNS),and recently it has become the major drugs of abuse.A lot of research results show that MA may induce dopaminergic neurotoxicity in the animal and human striatum.The mechanisms include effects on dopaminergic signaling and dopamine oxidation,glutamate induced excitotoxicity,oxidative stress and inflammatory cytokines,disruption of mitochondfia,apoptosis,activation of glial cells and hyperthermia.However the mechanisms by the MA-induced dopaminergic neurotoxicity are not completely understood.The paper reviewed recent progress of study on them to provide reference materials for related research.

Objective To prepare the “bacterial ghost” of E.coli with heat-induction and analyse its lysis rate and configuration. Methods Through immediately shifting the culture temperature from 37℃ to 42℃, E.coli DH5? including plasmid pMuH36 was induced to lyse, and the OD value of culture media was measured every 30 minutes during the induction. After 4 hours of induction, the bacteria samples were collected to examine the lysis rate by CFU (colony formation unit) and the configuration of lysed bacteria was observed by transmission electron microscopy (TEM). Results The OD value of DH5? (pMuH36)began to decline after 1 hour of induction, and increased slowly after 4 hours of induction. The CFU assay showed that the lysis rate was about 95%. TEM observation proved that most of the lysed bacteria were emptied, whereas the whole outmembrane structure, i.e. “bacterial ghost”, remained. Conclusions The E.coli “bacterial ghost” was efficiently prepared and identified, which might provide the basis for further development of a more effective “bacterial ghost” vaccine and adjuvant.

Objective To study the character of transformation of H.pylori into coccoid form under oxidative stress, and the changes in the biological charasteristics after transformation. Methods The coccoid form of H.pylori was studied with bacteriological, enymological, and genetical methods to identify its differences from the original form. Animal experiment was conducted to determine its implantation capacity. Results Morphological transformation from spiral to coccoid form occurred with the prolongation of culture under oxygen stress. The metabolic activity was reduced gradually, finally maintained at a lower level. The activities of urease, alkaline phosphatase and acid phosphatase were decreased markedly. The mRNA levels of main virulence factors were declined. Both mRNA and activities of enzyme of Sod B and Kat retained high levels. A part of the coccoid forms showed reversion to helical form, and colonization in mice stomach could be found after being inoculated to mice. Conclusions The metabolism and virulence of H.pylori were all lowered under oxidative stress, but a part of the coccoid form may be viable. Sod B and Kat may play an important role in the oxygen metabolism of H.pylori.

Objective To understand the control of medical waste disposal in Changsha. Methods The kinds, output, collection and disposal of medical wastes were investigated in three general hospitals, one tumor hospital and one paediatric hospital in Changsha. Results The main components of medical wastes were glass, plastic and cotton, which took 55%, 20% and 12% of the total output respectively. The daily outputs of medical wastes were 0.48?0.63 and 0.43 kg per bed in three general hospitals, 0.58 and 0.71 kg per bed in paediatric hospital and tumor hospital respectively. Based on these data, the daily output of medical wastes in Changsha was estimated about 9.390 t. The recovery rate of medical wastes mainly including glass and plastic was 49.32%. The disposal rate of medical wastes only was 1.34%. The rest of medical wastes of 49.34% were mixed into domestic wastes or landfilled. Conclusion The management of medical wastes wasn't perfect in Changsha, which presented potential environmental pollution.

Objective To investigate the diagnostic value of serum tumors M2 pyruvate kinase (TuM2-PK),carcino-embryonic antigen (CEA),CA199,CA724,CA125 and CA242 in colon cancer.Methods Serum levels of TuM2-PK,CEA,CA199,CA724,CA125 and CA242 in 231 patients with colon cancer,105 patients with colon benign lesion diseases and 166 normal controls were measured by the ELISA and electrochemiluminescence assays.The operation working characteristic curve (ROC) and the logistic regression-ROC were used to evaluate the diagnostic value of tumor markers for colon cancer individually and in combination.The models of logistic regression analysis and partial least-squares discriminant analysis (PLS-DA) were established to diagnose patients with colon cancer based on the optimal panel of serum tumor markers.Resalts Concentrations of serum TuM2-PK,CEA,CA199,CA125 and CA724 in the colon cancer group are higher than those in the colon benign diseases group and the normal controls (P＜0.05).The area under the operation working characteristic curve (AUC) of CA199 is the highest 0.79 [95％ confidence interval (95％CI),0.75-0.83] at the cutoff value of 69.5 U/L with 64.1％ of sensitivity and 89.7％ of specificity.The AUC of combined serum tumor markers based on logistic regression analysis is higher than those in individuals,of which serum (CEA+ CA199+TuM2-PK) is the optimal [AUC=0.89,95％ confidence interval(95％CI),0.86-0.92].The diagnostic accuracy of logistic analysis and PLS-DA model for colon cancer is 82.7％ and 77.5％,and for colon cancer is 93.7％ and 95.6％,respectively.Conclusion The combination of serum tumor markers CEA,CA199 and TuM2-PK is more suitable as a diagnostic model for the screening of colon cancer.

Phosphorylation of beta-catenin tyrosine residue 654 plays an important role in the epithelial to myofibroblast transition (EMT). Introducing mimic peptide of tyrosine residue 654 domain of beta-catenin into cells may influence phosphorylation of beta-catenin tyrosine residue 654. To deliver this mimic peptide into renal epithelial cells, we used penetratin as a vector, which is a novel cell permeable peptide, to deliver hydrophilic molecules into cells. A tyrosine 654 residue domain mimic peptide of beta-catenin (PM) with fused penetratin was constructed, purified and then detected for the penetration of the mimic peptide into human renal tubular epithelial cells (HK-2). The results showed that purified fusion mimic peptide could efficiently and rapidly translocate into human renal tubular epithelial cells. It is concluded that a cell-permeable peptides mimic of tyrosine residue 654 domain of beta-catenin was successfully obtained, which may provide a useful reagent for interfering the human renal tubular epithelial-mesenchymal transition.
Carrier Proteins/*metabolism ; Epithelial Cells/cytology ; Epithelial Cells/*metabolism ; Fibroblasts/cytology ; Fibroblasts/metabolism ; Kidney Tubules/*cytology ; Peptides/metabolism ; Permeability ; Phosphorylation ; Tyrosine/*metabolism ; beta Catenin/*metabolism