Use of concept maps to promote electrocardiogram diagnosis learning in undergraduate medical students.

Concept mapping is an effective method in teaching and learning, however this strategy has not been evaluated among electrocardiogram (ECG) diagnosis learning. This study explored the use of concept maps to assist ECG study, and sought to analyze whether this method could improve undergraduate students' ECG interpretation skills. There were 126 undergraduate medical students who were randomly selected and assigned to two groups, group A (n = 63) and group B (n = 63). Group A was taught to use concept maps to learn ECG diagnosis, while group B was taught by traditional methods. After the course, all of the students were assessed by having an ECG diagnostic test. Quantitative data which comprised test score and ECG features completion index was compared by using the unpaired Student's t-test between the two groups. Further, a feedback questionnaire on concept maps used was also completed by group A, comments were evaluated by a five-point Likert scale. The test scores of ECGs interpretation was 7.36 ± 1.23 in Group A and 6.12 ± 1.39 in Group B. A significant advantage (P = 0.018) of concept maps was observed in ECG interpretation accuracy. No difference in the average ECG features completion index was observed between Group A (66.75 ± 15.35%) and Group B (62.93 ± 13.17%). According qualitative analysis, majority of students accepted concept maps as a helpful tool. Difficult to learn at the beginning and time consuming are the two problems in using this method, nevertheless most of the students indicated to continue using it. Concept maps could be a useful pedagogical tool in enhancing undergraduate medical students' ECG interpretation skills. Furthermore, students indicated a positive attitude to it, and perceived it as a resource for learning.

Wnt and Notch signaling pathway involved in wound healing by targeting c-Myc and Hes1 separately.

INTRODUCTION: Wnt and Notch signaling pathways are critically involved in relative cell fate decisions within the development of cutaneous tissues. Moreover, several studies identified the above two pathways as having a significant role during wound healing. However, their biological effects during cutaneous tissues repair are unclear. METHODS: We employed a self-controlled model (Sprague-Dawley rats with full-thickness skin wounds) to observe the action and effect of Wnt/ß-catenin and Notch signalings in vivo. The quality of wound repair relevant to the gain/loss-of-function Wnt/ß-catenin and Notch activation was estimated by hematoxylin-and-eosin and Masson staining. Immunofluorescence analysis and Western blot analysis were used to elucidate the underlying mechanism of the regulation of Wnt and Notch signaling pathways in wound healing. Meanwhile, epidermal stem cells (ESCs) were cultured in keratinocyte serum-free medium with Jaggedl or in DAPT (N-[(3,5-difluorophenyl)acetyl]-L-alanyl-2-phenyl]glycine-1,1-dimethylethyl) to investigate whether the interruption of Notch signaling contributes to the expression of Wnt/ß-catenin signaling. RESULTS: The results showed that in vivo the gain-of-function Wnt/ß-catenin and Notch activation extended the ability to promote wound closure. We further determined that activation or inhibition of Wnt signaling and Notch signaling can affect the proliferation of ESCs, the differentiation and migration of keratinocytes, and follicle regeneration by targeting c-Myc and Hes1, which ultimately lead to enhanced or delayed wound healing. Furthermore, Western blot analysis suggested that the two pathways might interact in vivo and in vitro. CONCLUSION: These results suggest that Wnt and Notch signalings play important roles in cutaneous repair by targeting c-Myc and Hes1 separately. What's more, interaction between the above two pathways might act as a vital role in regulation of wound healing.

Molecular epidemiology of aminoglycosides resistance on Klebsiella pneumonia in a hospital in China.

To investigate the molecular epidemiology of aminoglycosides resistance among Klebsiella pneumonia in hospitals in China, the antibiotics resistance and the possession of extended-spectrum ß-lactamases (ESBLs) from 162 isolates were examined using Kirby-Bauer disk diffusion and PCR sequencing. Overall, 47.5% (77/162) of strains showed an ESBL phenotype. According to antibiotics resistance, ESBLs-positive K. pneumoniae showed significantly higher resistance to most antibiotics than ESBLs-negative strains (P<0.05). Moreover, 162 strains harboured aminoglycoside-modifying enzymes genes (AMEs) including aac (3)-II (n = 49), aac (6')-Ib (n = 32), ant (3")-I (n = 22) and ant (2")-I (n = 7). Overall, 11.1% (18/162) and 6.2% (10/162) of isolates carried 16S rRNA methylase genes (armA and rmtB), in which the aminoglycoside MIC was more than 256 µg/ml. In conclusion, our study characterised aminoglycosides resistance among K. pneumoniae strains in China hospitals and revealed antibiotic resistance and the increased presence of AMEs and 16S rRNA methylase genes in K. pneumonia, enabling the prevalence of aminoglycosides resistance of K. pneumoniae to be tracked from patients.

Prevalence and fluoroquinolone resistance of pseudomonas aeruginosa in a hospital of South China.

Pseudomonas aeruginosa is an opportunistic pathogen that poses a threat in clinical settings. This study aimed to investigate the molecular characterization and epidemiology of fluoroquinolones (FQs) resistance in P. aeruginosa isolated from South China. A total of 256 P. aeruginosa strains isolated from outpatients, emergency patients and inpatients were collected from January 2010 to December 2010 in the hospital of South China. The resistance profile of all isolated strains was screened by antibiotic-susceptibility testing, and the molecular characteristics of plasmid-mediated quinolone resistance (PMQR) and the quinolone resistance determining region (QRDR) were determined using PCR in combination with DNA sequencing. The result of antibiotic-susceptibility tests showed that most strains were sensitive to polymyxin B, piperacillin, piperacillin/tazobactam, ceftazidime and amikacin. Moreover, 65 isolates were identified as resistant to ciprofloxacin. Further analysis of QRDR revealed that the resistant strains carried at least one mutation in the gyrA (The83Ile), gyrB (Ser467Phe, Gln468His) and parC (Ser87Leu) genes, but no mutation was detected in parE. For the first time, we report here that the qnrA1 gene is associated with low levels of resistance to ciprofloxacin from clinical P. aeruginosa isolates in South China. The mutation of gyrA (at position 83) is clearly linked to the FQs resistance of P. aeruginosa. Moreover, FQs resistance of P. aeruginosa may be due to the chromosome-mediated resistance mechanism rather than PMQR.

Comparative serum proteome expression of the steroid-induced femoral head osteonecrosis in adults.

Steroid-induced osteonecrosis of the femoral head (SONFH) is a disabling, aseptic and ischemic disease that develops following steroid therapy. The pathogenesis of SONFH is unclear, so the early diagnosis and treatment for this disease is yet to be established. The purpose of the present study was to identify potential biomarkers for SONFH. The differential expression of serum proteins from patients with SONFH and healthy volunteers was analyzed by the proteomics method. The protein samples were labeled and subjected to isoelectric focusing and two-dimensional gel electrophoresis. The resultant protein spots were matched and quantified by an imaging analysis system. The differentially-expressed protein spots were subjected to in-gel trypsin digestion followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Significantly lower levels of complement component 3 (C3), C4, inter-α-trypsin inhibitor heavy chain H4 and α-2-macroglobulin were found in the serum of patients with SONFH. These proteins are reported to be actively involved in intravascular coagulation, apoptosis and reactive oxygen species imbalance, indicating that multiple pathological reactions occur in SONFH and these proteins may serve as potential biomarkers for the diagnosis of SONFH.

Experimental study of comparing rhEGF with rhßFGF on improving the quality of wound healing.

The mechanism and biological effects of comparing recombinant human epidermal growth factor (rhEGF) with recombinant human basic fibroblast growth factor (rhßFGF) were evaluated on the model of incised wounds on ventral side of rabbit's ears in order to direct their medication in clinical. Total of 72 incised wounds on ventral side of 24 New Zealand rabbits' ears were divided randomly into two therapeutic groups (rhEGF group with 10 µg/cm(2) and rhßFGF group with 100 AU/cm(2)) and a control group (1% silver sulfadiazine cream, SD-Ag). The observation of wounds, the measurements of healing wound area, the calculation of wound closing index, the histopathological examination, the electrical microscopic examination, and the expression of examining integrin ß1 mRNA of samples of three groups by in situ hybridization technique were used to evaluate the results of wound healing. The results showed that the wound healing was accelerated in all wounds treated with rhEGF and rhßFGF, and the quality of healing wounds of two therapeutic groups was better than that of the control group. In rhßFGF group, new granulation tissue was more than that of rhEGF group in earlier period and metaphase of healing wound, however, the velocity of re-epithelialization in rhEGF group was faster than that of rhßFGF group in metaphase and late period. The results indicate that rhEGF and rhßFGF can improve wound healing, but the detailed mechanisms and the biological effects were different. rhßFGF may be used to promote the growth of granulation tissue in earlier period and metaphase of healing wound, however, rhEGF may be used to accelerate the velocity of re-epithelialization in metaphase and late period. That rhßFGF and rhEGF were utilized in sequence can not only accelerate the velocity of healing wound and promote the quality of healing wound but also obtain the best ratio of effects versus value.

[Comparison of the effects of rhEGF with rhbFGF on the acceleration of wound healing].

OBJECTIVE: To investigate the mechanism and the accelerating effect of rhEGF and rhbFGF on wound healing. METHODS: Twelve New Zealand rabbits with 72 incised wounds on ventral side of 24 ears were randomly divided into two therapeutic groups (rhEGF of 10 ug/cm(2) and rhbFGF of 100 AU/cm(2)) and a control group (1% silver sulfadiazine cream, SD-Ag). The general conditions of the wound healing was observed grossly. Biopsies were harvested at different time points for the pathomorphological examination, the electron microscopic examination, and for assessment of integrin beta1 mRNA expression by in situ hybridization. RESULTS: The expressions of integrin beta 1 mRNA in two therapeutic groups were significantly higher than that of control group. The quality of the wound healing was improved in therapeutic group with its healing time shortened when compared with that in control group (P < 0.05). There was an obvious difference in the number of fibroblasts and capillary gemmules between the therapeutic and control groups (P < 0.05). CONCLUSION: The wound healing and quality could be improved by both rhEGF and rhbFGF, but rhbFGF seemed better to be employed during the early and middle stages of the wound repair for the growth of granulation tissue, while rhEGF should be applied at the late stage of wound repair to accelerate the re-epithelialization of the wound. Combined application of rhEGF with rhbFGF according to time effect could be more beneficial to the wound repair.