PBL teaching method is a new mode of teaching which is originated from the West and implemented into China in recent years with an expectation that it would mainly develop the students’ self-learning ability,and enhance their skills of comprehensive thinking and solving actual problems.The author summarizes the practical experience of using PBL teaching methods in the theory teaching in Department of Medical Microbiology and Human Parasitology,China Medical University in the past three years,and then proved this method is very helpful to improving the students’integrated thinking by analysis of sample.At the same time the results also suggested that the students showed high enthusiasm in discussing the cases.By this way,the students showed great subjective intiative in their studies.

China ; Genes, Bacterial ; Sequence Analysis ; Streptococcus suis ; classification ; genetics ; isolation & purification ; Virulence Factors ; genetics

Objective To develop a rapid, sensitive and specific assay method, based on multiplex real time PCR for identifying Vibrio cholerae and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae. Methods Cholera toxin A subunit gene (ctxA) and glycosyltransferase gene (LPSgt) were chosen as targets according to Vibrio cholerae and Vibrio cholerae O139 serotype,and then the primers and TaqMan-MGB probe were designed. The 5'end of probes was labeled with FAM and VIC fluoresceins respectively while the 3' end of probes was labeled with MGB. The PCR reaction was optimized systematically. Then the specificity, sensitivity and reproducibility of multiplex real time PCR were estimated. Finally, multiplex real time PCR was applied to detect the clinical specimens. Results Vibrio cholerae was identified by multiplex real time PCR accurately and quickly,which could distinguish Vibrio cholerae O139 serotype from Vibrio cholerae. Vibrio cholerae was identified positive for primer pairs and probes from ctxA gene, and Vibrio cholerae O139 serotype tested was positive for LPSgt gene. Meanwhile, none of other bacteria was identified. Sensitivity of the test was 2 × 102 cfu/ml. When this assay was applied directly to identify 45 clinical specimens, results showed that 10 were positive to Vibrio cholerae, in which 4 clinical specimens were positive to Vibrio cholerae O139 serotype. All the results were the same to the one that had been obtained from the conventional assays. Conclusion Our rsults showed that the multiplex real time PCR was a reliable,accurate and feasible method for identifying Vibrio cholerae that carrying toxin gene and distinguishing Vibrio cholerae O139 serotype from Vibrio cholerae. This method could be applied to the cholera surveillance, prevention and control system for identifying and distinguishing Vibrio cholerae in the labs.

Objective To investigate the impact of genetic and environmental factors on mental health status in adolescents twins. Methods A total of 52 pairs of twins aged 11 years were recruited with support from educational committees and school. After the guardians of these twins had signed an informed consent form,the Chinese version growth and the state of health evaluation (Development and Well-Bing Assessment,DAWBA) carries on twins' mental health growth condition investigation to the twins of Age greater than 11-year-old,and focus on a-nalysis of DAWBA youth-assessment version of more than 11-year-old twins. Buccal mucosa samples were collected from all twins for DNA extraction and zygosity identification test. Results The mood, the behavior symptom and the symptom produced the influence of the DAWBA and in the computer diagnosis' s result showed that the intra-pair correlation coefficience of the emotional disorder(rMZ=0, 200, P = 0. 28; r DZ = 0. 198, P = 0. 447) (MZ means was monozygotic,DZ means was dizygotie, r means was correlation), the special phobia symptom(r MZ = 0.440, P = 0.013;rDZ =0.419, P=0.094),the social phobia (rMZ =0.2%, P = 0. 106; r DZ = -0.119, P = 0.648),the depressive symptom (rMZ =0.556, P=0.001; rDZ = -0.254, P=0.325), and the oppositional/con-duct disorder(rMZ =0.503, P = 0.014; rDZ = -0.270, P = 0.295),eating disorder(r MZ =0.764, P=0.046; rDZ = -0.091, P=0.728) in Monozygotic twins was more remarkable than that in dizygotie twin. Conclusion The genetic factors play the vital role in affects in the child twins' mental health growth.

OBJECTIVETo investigate the expression of long non-coding RNA HOTAIR in the plasma of breast cancer patients and its value in the diagnosis of breast cancer.

METHODSHOTAIR levels were measured in 24 tumor tissues and 70 plasma samples from breast cancer patients using quantitative real-time PCR. The correlations of plasma HOTAIR level with the clinicopathological features of the patients were analyzed. A multivariate logistic regression model was established to analyze the value of plasma HOTAIR in comparison with plasma CA153 and CEA levels for breast cancer diagnosis. We further detected HOTAIR levels in the plasma and breast cancer tissues of 24 patients before and after operation and investigated their correlation.

RESULTSBreast cancer patients had increased expressions of HOTAIR in the tumor tissues and plasma, and plasma HOTAIR level was significantly correlated with estrogen receptor (ER) level (P=0.004) and lymph node metastasis (P=0.010). Receiver operating characteristic (ROC) curve and the multivariable logistic regression model showed that the area under ROC curve (AUC) of plasma HOTAIR was 0.82 (P<0.001) for breast cancer diagnosis with a diagnostic sensitivity and a specificity of 73.3% and 93.3%, respectively. The diagnostic power and specificity of plasma HOTAIR was much higher than those of CA153 (AUC=0.66, P=0.030) and CEA (AUC=0.52, P=0.001), and the combination of the 3 markers further enhanced the diagnostic power (AUC=0.84) and specificity (96.7%). Plasma HOTAIR level was significantly reduced in the patients after the operation (P<0.0001) and showed a moderate correlation with its expression in tumor tissues (r=0.62, P<0.0001).

CONCLUSIONPlasma HOTAIR may serve as a potential biomarker for breast cancer diagnosis.

Biomarkers, Tumor ; blood ; Breast Neoplasms ; blood ; diagnosis ; Carcinoembryonic Antigen ; blood ; Female ; Humans ; Logistic Models ; Lymphatic Metastasis ; Mucin-1 ; blood ; Prognosis ; RNA, Long Noncoding ; blood ; ROC Curve ; Real-Time Polymerase Chain Reaction ; Receptors, Estrogen ; metabolism ; Sensitivity and Specificity

OBJECTIVEDry powder inhalers (DPIs) are increasingly being used to deliver drugs for the treatment of asthma. It is known that DPIs require a crucial minimal inspiratory flow. Previous studies have demonstrated that the peak inspiratory flow (PIF, L/min) through a DPI is dependent on the type of device, the age of the patient, and the level of bronchial obstruction. However, the peak inspiratory flow of healthy preschool children in China remains scant in the literature. The present study aimed to analyze the ability of inspiring flow through the resistance state of ordinary use inhaler in Shenzhen healthy preschool children by measuring the peak inspiratory flow through the different analogue dry powder inhalers and go further into the relationship between it and the age, weight and forced expiratory volume of the children.

METHODA survey in 370 healthy preschool children aged 3 to 6 years (75 children aged 3 years, 104 children aged 4 years, 100 children aged 5 years and 91 children aged 6 years) was carried out in Shenzhen. Peak inspiratory flow (PIF) was measured without and with resistances, which mimicked the internal resistances of several inhalers, Diskus, Turbuhaler, Autohaler, Surehaler by PIF meter (In-check DIAL) and then data PIF-N, PIF-D, PIF-T, PIF-A and PIF-S were obtained. Peak expiratory flow (PEF) was measured by PEF meter (MicroPeak, USA). These two measurements were made in a well-controlled setting, and at least three attempts were recorded to establish maximum achievement. Six spirometry parameters forced vital capacity (FVC), forced expiratory volume at 0.5 second (FEV 0.5), forced expiratory volume at 0.75 second (FEV 0.75), forced expiratory volume at one second (FEV1), maximal mid expiratory flow rate (FEF 25 - 75, PEF were measured by using COSMED spirometry of Italy and the FVC measurements should be around the quality control for spirometry in preschool children which we suggested and published in 2005. All data were expressed as mean +/- SD and analyzed with the statistical software SPSS 12.0 for Windows. Pearson's test was used for calculation of the significances of the correlation coefficients. Variance analysis was used for analysing the variability of inspiratory flows through the inhalers.

RESULTSResults were obtained from 295 children aged 3 - 6 years who successfully finished the tests. The PIF-N, PIF-D, PIF-T, PIF-A and PIF-S were significantly different among the groups aged 3 yrs, 4 yrs, 5 yrs and 6 yrs. The peak inspiratory flow significantly increased with age. The PIF-N, PIF-D, PIF-T, PIF-A and PIF-S in the children of 110 cm height and above were significantly higher than those in the children below 110 cm height, so were the parameters between the children of 120 cm height and above and the children below 120 cm. PIF correlated significantly with age, height and weight and the Pearson coefficient was 0.3 - 0.5. The PIFs in different inhalers varied because of the different inner resistances. The minimum and optimum PIFs in resistances of Diskus, Autohaler and Surehaler could be achieved in almost all subjects, but those in resistances of Turbuhaler could be achieved in only 87.5% subjects, most of whom aged 3 yrs or below 100 cm height. There were good correlations between the PIFs in different resistances and main parameters of ventilation function (FVC, FEV 0.5, FEV 0.75, FEV1, FEF 25 - 75, PEF), PEF was the best among them (Pearson correlative coefficient was 0.6).

CONCLUSIONThe inspiratory ability of the children can be predicted and assessed by using routine measurement of lung function of normal pre-school children. As to the pre-school children of varying ages, the variety of inspiratory ability should be considered completely in the selection of inhaler used during the treatment. The best inhaler suitable for them should be selected properly in order to obtain the best efficacy of treatment individually.

Child ; Child, Preschool ; China ; Female ; Humans ; Inspiratory Capacity ; Male ; Maximal Expiratory Flow Rate ; Metered Dose Inhalers

OBJECTIVETo shorten the time of external skeletal fixation on legs, and enhance quality of limb lengthening, avoid complications of shortening, bending, twisting and etc.

METHODSInsert pin transcortical to attack external skeletal fixation simultaneously, put un-reaming locked intramedullary nail (do not insert distal locked screw) into endosteum of lengthening bone. After the legs achieved predetermined length, insert distal locked screw and then remove external skeletal fixation, locked intramedullary nail, then maintain consolidation of rehabilitation.

RESULTSThe group lengthened legs for 412 cases. The range of lengthening was 3 to 18 cm. Mean length was 7.6 cm. The mean time for needed external skeletal fixation was 20 d/cm. The mean time of osteogenesis was 56 d/cm. For complications, there were 3 tibias ununion cases and 1 varus ankle. All cases were treated undergoing twice.

CONCLUSIONSThe method reduces the time for needed external skeletal fixation visibly, enhances the quality of limb lengthening remarkably, prevents complications of shortening new bone, deformity, bending and re-fracture which do not effect the healing time. This is a new choice of limb lengthening.

Adult ; Bone Lengthening ; instrumentation ; methods ; Bone Nails ; Female ; Follow-Up Studies ; Fracture Fixation, Intramedullary ; instrumentation ; Humans ; Ilizarov Technique ; instrumentation ; Male ; Middle Aged ; Tibia ; surgery ; Treatment Outcome

OBJECTIVETo compare the image quality and radiation dose of prospectively electrocardiogram (ECG) -triggered spiral and sequential acquisition for coronary computed tomographic angiography by dual-source computed tomography.

METHODSSixty patients with suspected or known coronary artery disease were randomly divided into two groups. Group A underwent prospective ECG-triggering spiral scan and Group B underwent prospective ECG-triggering sequential scan. Both the image quality and radiation dose of the two groups were compared.

RESULTSThere was no significant difference in age and body mass index of the two groups. The average image quality score was 1.12 ± 0.38 in group A and 1.14 ± 0.38 in group B (Z=-0.291,P=0.771) . The rates of diagnostic coronary segments for two groups were 98.87% and 99.56% respectively (X2=0.59,P=0.443) . The mean radiation dose of group A was significantly lower than that of group B [ (1.31 ± 0.30) mSv vs. (3.36 ± 0.93) mSv; t=11.47, P=0.000] .

CONCLUSIONCompared with the prospective ECG-triggered sequential acquisition, the prospective ECG - triggered spiral scan for coronary computed tomographic angiography can remarkably reduce radiation dose without impairing image quality in patients with a low and stable heart rate (≤ 70 bpm) .

Aged ; Coronary Angiography ; methods ; Coronary Artery Disease ; diagnostic imaging ; Female ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Tomography, Spiral Computed ; methods ; Tomography, X-Ray Computed ; methods

OBJECTIVETo evaluate image quality (IQ) and radiation exposure of coronary computed tomographic angiography (CTA) with prospectively electrocardiographic (ECG) triggered high-pitch spiral acquisition using dual source CT.

METHODSTotally 75 consecutive patients with a stable heart rate (HR) ≤65 bpm underwent coronary CTA. patients were divided into two groups according to their HR (group A HR≤60 bpm, group B HR >60 bpm to≤65 bpm) . A dual-source CT scanner was used (0.6mm collimation, 0.28s rotation time, 80~100 kV, 370 mAs/rot) . Data acquisition was prospectively ECG-triggered at 60% of the R-R interval with a pitch of 3.4. Images were reconstructed with 75ms temporal resolution, 0.75mm slice thickness and 0.5mm increment. IQ was evaluated using a four-point scale (1=excellent, 4=unevaluable) .

RESULTSThe mean HR and scan time of all patients was (57.2 ± 4.8) bpm and (0.42 ± 0.02) s. Of 1103 coronary artery segments, 934 (84.7%) had an IQ score of 1, 135 (12.2%) score of 2, 18 (1.6%) score of 3,and 16 (1.5%) were rated as unevaluable. There was no significant difference between the two groups in IQ [mean score (1.19 ± 0.52 vs. 1.22 ± 0.55;Z=-1.107,P=0.268) . The rate of evaluable segments showed no significant difference between the two groups (98.5% vs. 98.6%;X2=0.000,P=1.000) . Mean dose-length product of all patients was (67.2 ± 30.4) mGy × cm, mean effective dose was (0.94 ± 0.43) mSv.

CONCLUSIONIn patients with a stable HR of 65 bpm or less, prospectively ECG-triggered high-pitch spiral CT acquisition provides high IQ at low radiation dose.

Aged ; Bradycardia ; diagnostic imaging ; Coronary Angiography ; methods ; Female ; Humans ; Male ; Middle Aged ; Quality Control ; Radiation Dosage ; Radiographic Image Interpretation, Computer-Assisted ; Tomography, Spiral Computed ; methods

Objective To study the single nucleotide polymorphisms (SNP) characteristics of Yersinia pestis strains from different natural foci in China.Methods Genome-wide comparison was done to find SNP sites by the Mummer program among 9 Yersinia pestis genome which was downloaded from NCBI.Then 13 genic fragments including 19 SNP sites were amplified by PCR and sequenced in 133 Yersinia pestis strains,and the results were cluster analyzed with the BioNumerics software.Results Three thousand seven hundred and eighty sequence variation sites were found by genome-wide comparison.Using the different combinations of SNP sites,UPGMA cluster analysis revealed obvious geographic regional and eco-aggregation characteristics of Yersinia pestis strains isolated from China.Conclusions As relatively stable genetic markers,SNP can better reflect the genome characteristics of Yersinia pestis in different plague natural foci of China.