Objective:To explore the effects of applying a four-step training method based on an attitude-skill-knowledge (ASK) model combined with workshops in training on the prevention and control of nosocomial infection among medical students, and to provide a reference for reforming nosocomial infection prevention and control training for medical students and establishing a nosocomial infection prevention and control training system.Methods:Medical students from five medical schools entering clerkships during 2018 to 2020 were selected. They were divided into control group (218 medical students in 2018-2019 receiving conventional nosocomial infection control training) and experimental group (216 medical students in 2019-2020 receiving nosocomial infection control training based on the ASK model-based four-step method combined with workshops). The two groups were compared in terms of the compliance rate of hand hygiene, the pass rates of nosocomial infection control theory and skill examinations, the correct rate of medical waste disposal, the incidence of occupational exposure, and the degree of satisfaction with teaching.Results:All the indices of the experimental group were significantly better than those of the control group: the compliance rate of hand hygiene ( χ2=4.92, P=0.027), the correct rate of medical waste disposal ( χ2=5.13, P=0.023), the pass rate of nosocomial infection control theory examination ( χ2=4.03, P=0.038), the pass rate of nosocomial infection control skill examination ( χ2=6.71, P=0.010), and the degree of satisfaction with teaching [(98.03±2.16) vs. (92.53±2.01), P<0.001]. No one had occupational exposure in the experimental group, while there were three cases in the control group. Conclusion:The ASK model-based four-step method combined with workshops is effective in nosocomial infection prevention and control training for medical students. This innovative training method improves students' satisfaction with clinical teaching, providing a basis for the establishment of a training system for the prevention and control of nosocomial infection.

Sarcopenia is a progressive syndrome associated with aging, generalized loss of skeletal muscle mass, muscle strength and function.It is closely related to the occurrence of adverse events such as ambulatorydysfunction, falls and fractures in the elderly, and seriously affects the quality of life of the elderly.The etiology of sarcopenia has not been fully elucidated.Various pathophysiological mechanisms such as reduced exercise, genetic factors, age-related hormone changes, malnutrition and insufficient protein intake, decreased neuromuscular function, pro-inflammatory cytokines, and myocyte apoptosis are possible factors.Recent studies have found that intestinal microecological changes may be implicated in the occurrence and development of sarcopenia.In this article, we reviewed intestinal microecological changes and their possible role in the mechanisms underlying sarcopenia.

Objective:To study the role of indocyanine green(ICG)fluorescence imaging in laparoscopic partial splenectomy (LPS).Methods:The data of 4 patients who underwent ICG fluorescence imaging technology for LPS at Beijing Luhe Hospital Affiliated to Capital Medical University from May 2017 to May 2020 were retrospectively analyzed. There were 3 females and 1 male, aged 46, 41, 27 and 12 years respectively. The extents of spleen preservation were compared between ICG fluorescence imaging with ordinary white light during operation. The residual splenic remnants were tested with fluorescence imaging after splenectomy, which showed fluorescence fading indicating good vascular perfusion.Results:ICG fluorescence imaging was performed on 4 patients. The operation time ranged from 180.0 to 250.0 min, and the intraoperative blood loss ranged from 40.0 to 200.0 ml. The postoperative hospital stay ranged from 4 to 14 days. There were no serious complications. Postoperative histopathology showed: splenic cyst ( n=1), splenic hemangioma ( n=2), and splenic laceration ( n=1). Conclusions:ICG fluorescence imaging technology had a significant role to play in partial splenectomy. This study showed this technique to improve safety of laparoscopic partial splenectomy.

Coronavirus disease 2019 (COVID-19) can cause great damage to the elderly patients and lead to high mortality. The clinical presentations and auxiliary examinations of the elderly patients with COVID-19 are atypical, due to the physiological ageing deterioration and basal pathological state. The treatment strategy for the elderly patients has its own characteristics and treatment protocol should be considered accordingly. To improve the diagnosis, treatment, and prevention of COVID-19 in the elderly, the Expert Committee of Geriatric Respiratory and Critical Care Medicine, China Society of Geriatrics established the "Expert consensus for the diagnosis, treatment, and prevention of coronavirus disease 2019 in the elderly" . We focused on the clinical characteristics and key points for better treatment and prevention of COVID-19 in the elderly. (1) For diagnosis, atypical clinical presentation of COVID-19 in the elderly should be emphasized, which may be complicated by underlying disease. (2) For treatment, strategy of multiple disciplinary team (mainly the respiratory and critical care medicine) should be adopted and multiple systemic functions should be considered. (3) For prevention, health care model about integrated management of acute and chronic diseases, in and out of hospital should be applied.

Objective To investigate the diagnostic accuracies among laparoscopic ultrasonography (LUS),CT,MRCP and transabdominal ultrasonography in secondary choledocholithiasis,and to compare the procedural efficacy of LUS carried out by surgeons assisted by ultrasound physicians,and by surgeons alone.Methods Forty-two patients underwent laparoscopic transcystic common bile duct exploration (LTCBDE) in Beijing Luhe Hospital,Capital Medical University.All these patients underwent LUS examination.In 26 patients,LUS was carried out by surgeons alone while in 16 patients it was assisted by ultrasound physicians.The results of intraoperative choledochoscopy were used to verify the results in the two groups in scan time,and in its accuracies when compared with CT,MRCP and preoperative abdominal ultrasound.Results The accuracy of LUS was 92.9％,which was significantly better than that of CT (73.8％) and transabdominal ultrasonography (23.8％,P ＜0.05).It was also better than that of MRCP (89.7％),though the difference was not significant (P ＞ 0.05).Surgeons alone were faster than ultrasound physicians in performing LUS [(8.5 ± 3.0) min vs (13.2 ± 4.6) min,P ＜ 0.05].There were no statistically differences between the two groups in accuracy (92.3％ vs 93.8％,P ＞ 0.05).Conclusion LUS diagnosed common bile duct stones by surgeons who had adequate ultrasound training,with a high accuracy rate and good efficiency.

Objective To compare the molluscicidal effects between“Luo-wei”(TDS),a plant molluscicide in 4 percent, and metaldehyde and niclosamide(MNSC)in the field. Methods A natural ecological environment with Oncomelania hupensis was selected as the test area,the test concentrations of TDS and MNSC were 2.5 g/m3 and 2 ml/m3 respectively by the immersion method;the test doses of TDS and MNSC were 3 g/m2 and 2 ml/m2 respectively by the spray method;the doses of WPN in a control group were 2 g/m3 and 2 g/m2 respectively by the two methods above-mentioned. The molluscicidal effects between TDS and MNSC were compared by using the synchronous design method and parallel comparative method. Results In the TDS group,the death rate of snails was 90.70%by immersion for 24 hours,reached to 81.40%after spraying for 7 days,and there were no significant differences among the observation time points in molluscicidal effects(P>0.05). One day after the spraying,the death rate of snails was less in the TDS group compared with that in the MSCN group(P<0.01),but the death rates of snails were similar in both groups 3 days after the spraying(P>0.05). In the MSCN group,the death rate of snails was 99.17%by immersion for 24 hours,reached to 66.07% by spraying for 1 day. In the WPS group,the death rate of snails was 97.15% by immersion for 24 hours,reached to 71.43%after spraying for 1 day,and there were no significant differences(both P>0.05). Conclusion TDS has a good molluscicidal activity and stable efficacy,and the molluscicidal effect of TDS is similar to that of MSCN in the filed, but the molluscicidal sensitivity of TDS is lower than that of MSCN.

Objective To establish a novel method for detecting circulating tumor cells (CTCs) in phripheral blood of lung cancer patients with high sensitivity and specificity.Methods Experimental study.42 cases of initial treatment patient who underwent resection and diagnosed to be non-small cell lung cancer by biopsy were studied,including 7 patients at stage Ⅰ,9 patients at stage Ⅱ,16 patients at stage Ⅲ and 10 patients at stage Ⅳ.As a control group,20 cases of healthy volunteers were selected.A series of experiments was conducted to determine the efficiency of tumor cells isolation,in which varied concentration (50,100,200,500,1000 cells) of A549 cells spiked into 2 ml peripheral blood drawn from healthy donors.The blood was removed of unwanted erythrocytes by lysis buffer,and made the rest of nucleated cells incubate with anti-EpCAM magnetic beads,then separated and enriched by a specific detector.All epithelia cells were retained on a slide because of a magnetic force and identified by H&E staining protocol.On the basis of cell recovery rate we calculated the sensitivity of tumor cells isolation.20 blood samples taken from healthy individuals were also detected to validate the specificity of this method.Samples of 42 patients with lung cancer were assayed for CTCs detection by above method.The correction of CTCs quantity with the patients' clinical features,for example,ages,gender,clinical stage,tumor size was analyzed in lung cancer patients by chi-square statistics.The correction of recovery cells with the spiked cells were assayed by linear correlation.Results The recovery rate was ranging from 68％ to 82％ by spiking varying numbers of A549 lung cancer cells into 2ml blood samples of healthy volunteers.Regression analysis of number of recovered vs.spiked A549 cells yielded a regression equation of Y =0.6419X + 8.8875.The number of CTCs detected has signification correlate with the cells spiked (R2 =0.9916,P ＜ 0.05),Eighteen of the 42 patients (43％) were found have CTCs in peripheral blood.The detection rate of lung cancer cells was 0 at stage Ⅰ,the detection rate of lung cancer cells was 11.1％ at stage Ⅱ,the detection rate of lung cancer cells was 62.5％ at stage Ⅲ and the detection rate of lung cancer cells was 70％ at stage Ⅳ.The positive rate of CTCs has no signification correlate with ages and gender of patients and tumor size (P ＞ 0.05),has signification with the clinical stage (P ＜ 0.05).None of the peripheral blood samples of the 20 healthy subjects analyzed was found to have CTCs.Conclusions This novel immunomagnetic separation technology is a sensitive and specific method,which provides a new tool allowing for feasible and specific detection of CTCs in lung cancer patients.The level of CTCs increases with the clinical stage and tumor size increased,which has important value to discover the early stage micrometastasis and redefine the clinical stage.But further multicenter and large sample clinical research are needed to confirm its clinical value.

Objective To investigate the correlation between the expression level of BLM and its clinical significance in leukemia.Methods 125 bone marrow specimens of inpatients and outpatients with leukemia were collected in Anhui provincial hospital from January 2011 to December 2011.125 leukemia patients were diagnosed and classified into acute leukemia (AL,n =66) and chronic myelogenous leukemia (CML,n =59) by Morphologic and Immunologic criteria,5 non-tumor individuals were included as control group.The BLM mRNA expressions were by reverse transcription-polymerase chain reaction(RT-PCR).The specimens were devided into groups according to the age,gender,leukemia type,peripheral blood leukocyte counts,hepatomegalia and(or) splenomegaly,fusion gene,chromosome karyotype,whether first visit and transplantation.The expression of BLM gene in each group and the correlation with above factors were retrospectively analysed.The statistical methods such as chi-square test,single factor variance analysis,t test and Pearson correlation test were mainly used.Results BLM mRNA was detected in leukemia.In bone marrow cells,the BLM gene expression was positive in 71 patients and negative in 54 patients.But none of 5 non-tumor bone marrow cells expressed BLM gene.The difference of BLM expression between patients and controls was statistically significant in two groups,i.e.peripheral blood leukocyte counts and fusion gene (x2 =14.730,22.399 ; P ＜ 0.05),but there is no statistical significant differences in other groups.The expressions of BLM mRNA in leukemia patients who had been treated with chemotherapy were lower than those newly diagnosed (0.1788 ± 0.1091 vs 0.3276 ± 0.2016 ; P ＜ 0.05).Moreover,BLM mRNA level in post-bone marrow transplant patients was lower than those not treated (0.1271 ± 0.1009 vs 0.2902 ±0.2034 ; P ＜ 0.05).Pearson correlation analysis showed that higher BLM mRNA expression positively correlated with fusion gene (r =0.357,P ＜ 0.01) and chromosome abnormality (r =0.279,P ＜ 0.05).Conclusion The BLM mRNA expression level of measurement can be used as judgment for leukemia patients disease severity and the index of prognosis,testing the level may provide a basis for clinical and curative effect judgment.

Objective To establish a real-time fluorescence quantitative PCR method for detection of the different expression level of FPGS in methotrexate enantiomer-resistant A549 cell lines,and observe FPGS mRNA expression in patients with leukemia.Methods A real-time fluorescence quantitative PCR method for detection FPGS mRNA was established using SYBR Green Ⅰ as fluorescence and β-actin as reference.The method was evaluated by Ct,correlation coefficient,slope,repeatability curve,melting curve and amplification efficiency curve.The expression levels of FPGS gene in methotrexate enantiomer-resistant A549 cell lines and methotrexate resistant leukemia cells in bone marrow were detected by the method.Results The standard curves had a high linear relationship between cycle threshold and template concentration.The correlation coefficients of FPGS and β-actin were 0.996 8 and 0.998 7,and the slopes were -3.595 and -3.740,respectively.The inter-coefficient of variation was from 1.27% to 2.95%.The intra-coefficient of variation was 3.82%.The method was characterized with specific melting curve and similar amplification efficiency(slope was 0.021 7).The relative contents of FPGS mRNA were(3.51 ±0.66),(0.16 ±0.01) and(1.00 ±0.31) in L-(+)-MTX/A549 cells(L),D-(-)-MTX/A549 cells(D)and A549 parent cells,and there was statistically difference among the three groups(F = 64.45 ,P＜ 0.01)Statistical difference was observed between L and D(q =9.29,P＜0.01).After treated with MTX,the expression level of FPGS mRNA was(0.35 ± 0.04) in methotrexate resistant leukemia patients,compared with(1.00 ± 0.44) before treatment.Statistical difference was observed(t = 8.83 ,P＜ 0.01).Conclusions The real-time fluorescence quantitative PCR is suitable for the quantification of FPGS.The expression levels of FPGS in methotrexate resistant leukemia cells in bone marrow and drug resistant cells are different.Two enantiomer forms of methotrexate may play different roles in drug resistance mechanisms.

Objective To develop an assay with polyclonal antibodies against a fragment derived from human albumin for determination of a peptide in urine, and to provide an early diagnostic tool for GVHD. Methods A small peptide composed of 16 amino acids (LVRYTKKVPQVSTPTL) was synthesized artificially. The immunogen was then diluted into 100 μg/kg body weight of rabbit. Subcutaneous injection in the immune animals was performed on both sides of spine and groin with 2.5 ml antigen suspension for three times, in order to prepare the polyclonal antibodies. The peptide antigen was then labeled with fluorescein isothiocyanate (FITC), and detected by LIF-CE-IA with the pre-prepared antibodies. Results The titer of serum. The migration time of the labeled antigen was 5.93 min, while the migration time of antigen-antibody complex was 6.47 min. The linear range of the method was 16 to 512 ng/ml, and the minimum detection limit was 10 ng/ml. Conclusions The polyclonal antibodies against the peptide antigen was isolated successfully, which possessed high titer and specificity. These results indicated that the assay was simple and rapid and could be applied for the early diagnosis of patient with GVHD.