Certain public service pre-school teachers have been trained as vision screeners of children. However, there are no studies that assessed the knowledge and skills retention of these screeners. This study determines the level of knowledge retention among pre-school teachers who have been trained to perform vision screening on children. In 2013, 180 KEMAS pre-school teachers were recruited in a vision screening training which included both theory and practical sessions. Teachers were assessed through a theory test which comprised of 15 questions, firstly a category on the preparations needed for vision screening and secondly on the implementation of vision screening. They were then asked to conduct pre-school vision screening annually at their working premises. In 2016, 136 teachers who had been involved in the earlier program were recruited as subjects in this study. All these subjects answered the same set of theory test questions used in 2013. The Student’s t-test result indicated that the mean theory test scores obtained by the pre-school teachers in 2013 (84.3 ± 7.8) differed significantly with the mean scores obtained in 2016 (67.5 ± 11.3) (p < 0.001). The mean scores in 2013 for questions in the first and second categories were 4.5 and 4.4, decreasing to 4.2 and 3.7 in 2016. The knowledge level of pre-school teachers thus decreased with time and this effect was found significant after 3 years. There is therefore a need to conduct re-certification training, so that the screening conducted by these pre-school teachers remains effective and in accordance with established standards.

Endothelial injury or dysfunction leads to multiple cardiovascular diseases, such as atherosclerosis, myocardial infarction, stroke, hypertension and peripheral vascular disease. Endothelial progenitor cells (EPCs) are precursor cells of endothelial cells, including the early endothelial progenitor cells and the late endothelial progenitor cells. hTese two EPC types have different function and surface markers. EPC in this article mainly means late endothelial progenitors which could grow into endothelial cloning and form vessels in vivo. Late EPCs can express CD133, CD31, KDR, CD144, CD34 etc, take in low density lipoprotein, bind with ulex europaeus lectin 1 and form blood vessels in vitro and in vivo. EPCs not only participate in new blood vessels formation, but also are closely related to the repair of damaged endothelium. Many studies conifrm that the transplanted EPCs are able to be mobilized to vascular injury location and repair the damaged endothelial cells thus promote new blood vessel formation, which provides a promising strategy for the treatment ofcardiovascular diseases and ischemic diseases.

It is found in clinical practice that decisions made by agents on hehalf of the patients without capability of independent choice may sometimes conflict interests of the patient in question. The author summarized by categories common dilemmas faced by clinicians, and came up with the ethical principles to resolve the problems, as proven in case studies. Doctors should fully respect reasonable decisions of agents of such patients. Furthermore, to make a reasonable decision on their behalf, the agent is expected to make medical decisions in the interests of the life and health of the patient, with adequate knowledge of the disease, therapeutic measures and outcomes, and without any damage to interests of the patient they represent. Such a reasonable decision should neither violate laws of the state, nor infringe on interests of other individuals, collectives and the society at large for benefits of the patient in question. In addition, it should conform to the medical ethics of fair distribution of health resources.

Objective To investigate the changes of fractional exhaled nitric oxide (FENO)) and their relation with lung function in bronchial asthma.Methods FENO and forced expiratory volume in the first second (FEV1) were measured during the periods of acute onset,chronic persistence and paracmasis in 54 patients with asthma and 19 healthy persons.Results There were significant differences in the levels of FENO and FEV1 among the course of acute onset [(57.59 ± 32.24) ppb and (1.72± 0.33) L],chronic persistent course [(40.02 ± 15.68) ppb and (2.41 ± 0.23) L],paracmasis [(26.71±6.07) ppb and (2.82±0.29 )L]and control[(14.74±3.42 ) ppb and (2.93±0.13)L] (F=19.555,163.096,P＜0.01) except for the levels of FEV1 between paracmasis and control group(P＞0.05).The negative correlation between FENO and FEV1 was found in the course of acute onset(r=- 0.666,P =0.005 ),but not in the chronic persistent course ( r =- 0.288,P =0.176) and paracmasis(r=-0.246,P=0.457).Conclusions The level of FENO is increased and may be useful to evaluate control degree in patients with asthma.

Objective To investigate the serum level of calcium-binding protein A9(S100A9)in patients with rheumatoid arthritis and explore its potential clinical significance. Methods The serum level of S100A9 was measured by ELISA in 79 rheumatoid arthritis (RA) patients and 20 healthy controls (HC). The correlation of S100A9 level and relevant clinical parameters were analyzed. Results The serum level of S100A9 was significantly increase in RA patients than those in HC. The serum level of S100A9 was higher in high disease activity than that in moderate and low disease activity in the RA group. There was a positive correlation in serum S100A9 level and DAS28 score,Rheumatoid factor,tender joint count and swollen joint count. Conclusion The serum level of S100A9 increases in RA patients and correlates with RA activity.

Objective To construct an expression vector directed by hU_(6)snRNA promoter for synthesizing small RNA and to identify its functional activity in the gastric carcinoma cells——SGC-7901.Methods Using human genomic DNA as template,U_(6) snRNA promoter was obtained by PCR method,and then cloned into PUC19 vector to produce the recombinant plasmid PUC-hU_6-extra,which was sequenced and then transfected into gastric carcinoma cell——SGC-7901 with liposome.The effect of expression directed by U_6 promoter was detected by RT-PCR method,and the cell proliferation curve analysis was performed by stained dye.Results The hU_6 snRNA promoter with the first 27 nucleotides followed were successfully cloned into PUC19 plasmid.The recombinant vector could efficiently transcribe small RNA molecules and exerted no effect on cell proliferation in SGC-7901 cells in vitro.Conclusion We have successfully constructed the recombinant PUC-hU_6-extra plasmid vector that can efficiently transcribe small RNA molecules directed by hU_6 snRNA promoter in the gastric carcinoma cells——SGC-7901.

Objective: To study rDNA ITS (internal transcribed spacers) sequences variation from di erent population of Aquilaria sinensis in main habitat of China. Methods: The rDNA ITS regions of various A. sinensis were ampli ed by PCR method and sequenced, and they were analyzed by means of the software of CLUSTAL and MEGA. Results: The sequences of rDNA ITS region of A. sinensis were reported for the rst time, and the sequences of ITS region were 680bp (ITS1 246bp, 5.8S 163bp, ITS2 271bp). There were 6 variable sites among populations and the genetic distance were 0.0% to 1.1%,which indicated the intraspecific genetic variation was low of A. sinensis. Conclusion: The variation of rDNA ITS sequences can be used to authenticate A.sinensis from di erent geographical regions and their adulterants.

Objective To investigate ultrasonographic features of primary and metastatic ovarian yolk sac tumors.Methods Ultrasonographic features of 19 primary lesions and 33 metastatic lesions in 35 patients were retrospectively analyzed.Results Primary tumors were sized (14.6±3.6)cm in maximum diameter,manifesting as cysti-solid masses.Solid components of primary tumors were mainly hypoechoic or isoechoic(16/19)with rich blood supplies.Thirty-three metastatic lesions were located in pelvoceliac cavity(26/33) and liver parenchyma(7/33),sized (9.4±4.5)cm,(9.2±4.9)cm and (5.6±1.6)cm in maximum diameter respectively.Metastatic lesions in pelvoceliac lesions mainly demonstrated as hypoechoic masses(21/26), however lesions in the liver were mainly hyperechoic(5/7).Anechoic regions could be found in 9/26 of the pelvoceliac lesions.Blood supply was found less rich in metastatic masses than that in primary ones.Elevated serum level of alpha fetoprotein (AFP) was observed in all patients; ranging from 217 to 211 682 μg/L.Conclusions Primary and metastatic lesions of ovarian yolk sac tumor have obvious ultrasonographic characteristics.Combined with serum AFP level,the accuracy of diagnosis could be improved.

Objective To study the role and clinical significance of chemokine receptor-4 (CXCR4) and vascular endothelial growth factor (VEGF) in the occurrence and development of renal cell carcinoma. Methods Expression of CXCR4 and VEGF were detected by SP immunohistochemical technique in 56 cases of kidney carcinoma tissues (including 20 cases of lymph node metastasis), 10 normal tissues nearby kidney cancer. Results The positive rates of CXCR4 and VEGF were 66. 1% (37/56) and 73. 2% (41/56),which were significantly higher than those in normal tissues( 20. 0% (2/10) and 30. 0% (3/10), respectively) (P ＜ 0. 05 ＝. The expression of CXCR4 protein was significantly positively correlated with that of VEGF protein (r = 0. 315 ,P ＜ 0.05 ＝ in renal cell carcinoma. The expression of CXCR4 and VEGF was closely related to stages of tumor ( χ2 = 9. 520, P = 0. 023; χ2 = 9. 072, P = 0. 027 ), lymphatic metastasis, degree of invasion ( χ2 =4. 972, P = 0. 026; χ2 = 3.910, P = 0. 034 ), and microvessel density ( MVD) ( P ＜ 0. 05 ＝. However, they were not related to sex ( χ2 = 0. 020, P= 0. 887; χ2 = 0. 001, P = 0. 716 ), tumor size ( χ2 = 0. 003, P = 0. 995; χ2 =0. 108, P = 0. 990) and pathologic types ( χ2 = 1. 960, P = 0. 900; χ2 = 0. 112, P = 0. 994). Conclusion There is a significant positive correlation between high expressions of CXCR4 and VEGF proteins in renal cell carcinoma,the high expressions of CXCR4 and VEGF proteins may be related to the metastasis and prognosis of renal cell carcinoma,thus they could be used as important indicators in judging the metastasis prognosis of renal cell carcinoma,and offer prospects for the treatment of renal cell carcinona.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide and has high mortality and recurrence rates and low survival rates. Circular RNAs (circRNAs) are a class of single-stranded closed circular RNA molecules with tissue- and development-specific expression and play a regulatory role in organisms. These circRNAs regulate the progression of HCC by acting as miRNA sponges and targeted protein-coding genes, but the basic mechanism is still unclear. This article summarizes the formation mechanism and biological functions of circRNAs, reviews the research advances in the role of circRNAs in the pathogenesis of HCC, and points out their potential value as diagnostic markers and therapeutic targets for HCC.