The paper sorts out and analyzes papers on medical English teaching and research published in core periodicals of China. The results show that there are various problems: slow research progress, insufficient empirical studies, a shortage of research on teachers and students, a lack of young faculty members and insufficient international perspective. With the increasing requirement for medical students' higher language proficiency imposed by the development of higher medical education in China, this paper puts forward some suggestions based on the analysis of the past ten-year data on medical English teaching and research: to build stronger medical English teaching faculty and to enhance their research competence by means of improving, enlarging and cooperating; to intensify the research into the two subjects in the teaching process: medical English teachers and medical students; and to avoid depending too heavily on questionnaire survey and employ multiple research methods and collect effective data in order to fundamentally improve medical English teaching and research.

The intakes of Al, Ca, Mg, Zn, Fe or P in the diet of college students were determined with chemical methods and the effects of Al on several elements were observed. The results showed that the mean intake of Al was 4.59 mg/d for students and the mean daily intakes of Ca, Zn, Fe were 40.1%, 81.8%, 191.1% of RDA, respectively. Higher intake of Al (33.88mg/ person/d) did not apparently influence the serum Al, Ca, Mg, Zn and Fe levels in short time. The multiple stepwise regression analysis found that there was a positive correlation between the serum Al content and P intake and a negative correlation between the serum Al content and Mg intake. Further studies were needed for the effects of Al on Ca, Mg, Zn, Fe and P metabolism.

OBJECTIVETo explore the relationship between salivary proteome and dental caries and to promote the biomarker studies of dental caries susceptibility by comparing the salivary proteome of caries-active children and caries-free children with electrospray ionization ion-trap tandem mass spectrometry (ESI-MS/MS).

METHODSTen caries-active children and ten caries-free children were sampled. The salivary proteome of the two groups was studied, and the differential protein between the two groups was analyzed by ESI-MS/MS after sodium dodecyl sulfate polyacrylamide gel electrophoresis, filter-aided sample preparation, and liquid chromatography.

RESULTSThe concentration of salivary protein was higher in the caries-active group than in the caries-free group. The polypeptide counts of thecaries-active and caries-free groups were 602 and 481, which belonged to 286 and 227 proteins, respectively. The differential polypeptide count of the two groups was 361, and the differential protein count was 118. The detected proteins included matrix metalloproteinase-9 (MMP9), mucin-7 (MUC7), lactotransferrin (LTF), carbonic anhydrase 6 (CA6), azurocidin (AZU), and cold agglutinin.

CONCLUSIONThe total salivary protein was higher in the caries-active group than in the caries-free group. The preliminary detection of differential proteins (MMP9, MUC7, LTF, CA6, AZU, and cold agglutinin) may lay some foundation for biomarker research of dental caries susceptibility.

Carbonic Anhydrases ; Child ; Dental Caries ; Humans ; Matrix Metalloproteinase 9 ; Proteome ; Saliva ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry

Ticks transmit various diseases to livestock and human beings. The researches on ticks are of great importance in medical and veterinary sciences. To express a glutathione peroxidase gene (HlGPx) from Hemaphysalis longicornis in Escherichia coli (E. coli) so as to provide basis for further studies, the gene was amplified from cDNAs of H. longicornis adult ticks by PCR prompted by information from EST library. The TGA codon encoding selenocysteine in the gene was mutated into the universal genetic code for cysteine,TGC, by site-directed mutagenesis. E. coli was transformed with the recombinant expression vector pGEX-4T-1/HlGPx'(the mutated HlGPx) and induced to express recombinant HlGPx', which was then analyzed by sodium dodecylsulphate-polyacrylamide gel electrophoresis and Western blotting. The result showed that the complete coding sequence of HlGPx was obtained successfully, the deduced polypeptide was 223 aa, with a calculated molecular mass of 25.0 kDa; the recombinant fusion protein was approximately 51 kDa, correspondent to the calculated. The antibody against glutathione S-transferase (GST) recognized the recombinant protein fused with GST in a Western blotting assay, which confirmed the result above-mentioned. In conclusion, the mutated HlGPx was expressed in E. coli successfully and it could be used for further preparation of immune serum and functional analysis.

Objective To explore the effects of homocysteine (Hcy) on neural stem cell (NSC) proliferation and the mRNA expression level of Notch1 and Hes1 related Notch signaling pathway from neonatal rats in vitro. Methods NSCs from neonatal rats were cultured by serum-free culture method in vitro. Cells were divided into four groups: control group (Hcy-C), low dose Hcy (Hcy-L) group, middle dose Hcy (Hcy-M) group and high dose Hcy (Hcy-H) group. NSCs were iden- tified by immunofluorescent staining using the antibodies against Nestin, β-tubulin Ⅲ and GFAP. The proliferation ability of NSCs was detected by MTT. The mRNA expressions of Notch1 and Hes1 were detected by Real-time PCR. Results In the serum free suspension medium, neurospheres that consisted of a great number of nestin-positive cells were found. β-tu- bulin Ⅲ positive neurons and GFAP positive astrocytes were detected by immunofluorescence staining on the 6 th day of cell induction. MTT assay showed that the cell viability was significantly lower in three Hcy treatment groups than those of con- trol group (P ＜ 0.05). And the effect of concentration-dependent was observed. The results of RT-PCR showed that mRNA expression of Hes1 was significantly lower in three Hcy treatment groups than that in control group (P ＜ 0.05). The mRNA ex- pression of Notch1 was significantly lower in Hcy-H group than that of other three groups (P ＜ 0.05). The mRNA expression of Notch1 was significantly lower in Hcy-M group than that of Hcy-L group and control group (P ＜ 0.05). Conclusion Hcy could inhibit the proliferation of NSCs by down-regulating mRNA expression levels of Notch1 and Hes1 genes related to Notch signal pathway.

Objective To explore the role of homocysteine(Hcy)on angiogenesis at peri infarct region after focal cere-bral ischemia in rats, to elucidate inhibitory factors of angiogenesis, and to establish a clinic foundation for clinical brain functional recovery. Methods Spragur-Dawley (SD) male rats (n=36) were randomly divided into three groups with 12 rats in each group including Sham Operation (SO) group, Middle cerebral artery occlusion (MCAO) group and MCAO+Hcy group. The rats in Sham and MCAO groups were intra-peritoneally injected with 5 mL/(kg·d) saline and rats in MCAO+Hcy group were injected with 2%5 mL/(kg·d) Hey solution from the same route. MCAO was introduced by intraluminal filament meth-od after 7 d Hcy intervention. Rat brains were harvested on the 7th day after MCAO. BrdU(50 mg/kg, as a marker of cell pro-liferation)was intraperitoneally injected three days before the rats were killed. High performance liquid chromatography (HPLC)was used to measure serum Hcy concentration in rats. Brain infarction size was observed by TTC staining. Immuno-fluorescence staining was used to detect the number of BrdU+/laminin+cells at the thalamus of infarction side. Results Se-rum Hcy concentration significantly higher in MCAO+Hcy group than in SO and MCAO groups(P<0.05). Brain damage increased and the number of BrdU+/laminin+cells decreased in MCAO+Hcy group compared with those of MCAO group (P<0.05). Conclusion Increased Hcy concentration in rats lead to more severe damage of cerebral infarction as well as to inhibit the angiogenesis at surrounding ischemia area.

Objective To investigate the effects of folic acid on apoptosis of neural cells after focal cerebral ischemia injury in rats and the mechanisms.Method Thirty two adult male Sprague-Dawley(SD) rats were randomly divided into sham operation group(SO),middle cerebral artery occlusion group(MCAO),MCAO+ low dose folic acid group(MCAO+FA-L) and MCAO+ high dose folic acid group(MCAO+FA-H).The model of middle cerebral artery occlusion(MCAO) was set up by using intraluminal filament method.The rats were sacrificed at D7 day after cerebral ischemia.The apoptotic rate of neural cells was examined by TUNEL test,and the expression of pERK1/2 protein was detected by Western blotting method,The MDA content and serum SOD and GSH-Px activities in rats were measured before and 28d after folic acid treatment and 7th day after ischemia.Results Compared with ischemia group,the apoptotic rate of neural cells and MDA content in both folic acid supplemented groups were decreased significantly(P

Objective: To investigate the effects of folic acid (FA), vitamin B6 (VB6) and B12 (VB12) on plasma homocysteine (Hcy) and antioxidative activities in focal cerebral ischemia rats. Method: Rats were randomly divided into four groups including sham operation (Sham), middle cerebral artery occlusion model (MCAO), MCAO+FA and MCAO+FA +VB6+VB12(MCAO+CV). MCAO model was induced by operation. Plasma Hcy, serum and brain SOD and GSH-Px activities and MDA content in rats were measured before and 28 d after supplementation and 24 h after ischemia or only after ischemia. Results: Plasma Hcy in MCAO+FA and MCAO+CV group were significantly lower than those in Sham and MCAO groups after supplementation and ischemia, and the MCAO+CV group lower than MCAO+FA group. Serum and brain SOD and GSH-Px activities were significantly higher, and MDA contents lower in MCAO+FA and MCAO+CV groups than those in MCAO group. Conclusion: Supplementing FA, VB6 and VB12 can reduce plasma Hcy, improve antioxidative abilities and decrease the injury by oxidative stress following cerebral ischemia.

Objective To explore the effect of folic acid on neural stem cells(NSCs) proliferation from fetal rats in vitro.Method NSCs were isolated and cultured by microdissection,mechanical blowing and serum-free suspension culture,and identified by immunofluorescent staining using antibody against nestin.BrdU(5’bromo-2’deoxyuridine) was used to mark dividing neural stem cells.Cultured NSCs were divided into four groups:control group,low,high dose group(liquid media with added 4,40 mg/L folic acid),and deficiency group(liquid media with added 0.4 mg/L methotrexate,MTX).Monotetrazolium(MTT) and double-label immunofluorescence technique detected NSCs proliferation under the condition of folic acid.Results In the serum-free suspension medium,neurospheres that consisted of a great number of nestin-positive cells could be obtained.The proliferative ability of NSCs were observed by BrdU labeling methods.MTT assay and double-label immunofluorescence for nestin+BrdU showed that the growth tendency was increased with folate concentration in the medium.Compared with control group,NSCs growth rate of folate group was significantly increased in vitro.Conclusion The culture of NSCs isolated from fetal rats possesses the abilities of proliferation and self-regeneration.Folic acid may stimulate proliferation of NSCs efficiently.