Problem-based learning(PBL)is an important part of creative education in medical colleges.Choice and design of cases are of the vital importance to success or failure of PBL course.To enhance students' ability of independent,creative thinking,and their ability of analyzing and solving problems,the roles of primitive cases and model cases as well as interrelation between them were discussed respective- ly.Moreover,five basic principles to be followed in model case design for PBL in Medical Microbiology and Human Parasitology,i.e.objec- tivity,flexibility,consistency,illumination and relevance,were proposed in this study.

Objective To investigate the nasal colonization of Staphylococcus (S.) aureus strains among medical university students in Shenyang and to study the molecular epidemiological characteristics of methicillin resistant S. aureus (MRSA) strains. Methods Sterilized nasal swabs were used to collect nasal bacteria from both nares of the students. Nasal specimens were further identified as S. aureus strains, sensitive or resistant to methicillin through a series of tests. Molecular related methods including staphylococcal cassette chromosome mec (SCCmec) typing, pulsed- field gel electrophoresis (PFGE) , coagulase isotyping and minimum inhibitory concentration (MIC) determination etc. were used to characterize the isolates. Prevalence of the panton-valentine leukocidin (pvl) genes (lukS and F-PV) among the isolates was also assessed. Results Staphylococci were found in 488 specimens from 977 participants through the surveillance program, conducted in 2009. Of the 488 specimens being tested, 364 were identified as coagulase-negative staphylococci (CoNS) and 124 as S. aureus. MRSA strain among the S. aureus isolates was accounted for 3.4%. In the surveillance program conducted in 2010, staphylococci grew in 310 specimens fiom 657 participants. Of the 310 specimens tested, 195 were identified as CoNS and 115 as S. aureus. The percentage of MRSA strains among the S. aureus isolates was 7.7%. In total, 239 students carried S.aureus, and the percentage of MRSA carriers among the total specimens tested in this study was 5.1%.Most of the MRSA strains could be classified into one of the five types of SCCmec elements. Type Ⅳ a SCCmec strains were most frequent seen overall (10 isolates). A total of 11 pulsotypes were identified among the MRSA strains and were classified into 7 major groups (A to G) by the mutual correlations of their banding patterns. Ten MRSA strains were identified as pvl positive strains. Conclusion An MRSA clone (Ⅳ a SCCmec pulsotype A) carrying pvl toxin gene was found to be prevalent in the nares of the healthy university students.

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.

OBJECTIVETo evaluate autogenous vein grafts and inside-out vein grafts as conduits for the defects repair in the rabbit facial nerves.

METHODSThe 10 mm segments of buccal division of facial nerve were transected for 48 rabbits in this study. Then the gaps were immediately repaired by autogenous vein grafts or inside-out vein grafts in different groups. All the animals underwent the whisker movement test and electrophysiologic test during the following 16 weeks at different time points postoperatively. Subsequently, the histological examination was performed to observe the facial nerve regeneration morphologically.

RESULTSAt 8 weeks after operation, the facial nerve regeneration has significant difference between the experimental group and the control group in electrophysiologic test and histological observation. However, at the end of this study, 16 weeks after operation, there was no significant difference between inside-out vein grafts and standard vein grafts in enhancing peripheral nerve regeneration.

CONCLUSIONThis study suggest that both kinds of vein grafts play positive roles in facial nerve regeneration after being repaired immediately, but the autogenous inside-out vein grafts might accelerate and facilitate axonal regeneration as compared with control.

Animals ; Axons ; physiology ; Facial Nerve ; physiology ; surgery ; Facial Nerve Injuries ; surgery ; Male ; Nerve Regeneration ; physiology ; Rabbits ; Transplantation, Autologous ; methods ; Veins ; transplantation

BACKGROUNDThe heavy incidence and mortality of hemorrhagic fever with renal syndrome, as well as no specific drugs in curing the disease, clearly indicate the need for development of the more effective hantavirus vaccine. Refining the DNA vaccination strategy to elicit more clinically efficacious immune responses is now under intensive investigation. In the present study, we examined the effects of using an interleukin-12 expression plasmid as a genetic adjuvant to enhance the immune responses induced by a DNA vaccine based on the S gene encoding nucleocapsid protein against hantavirus.

METHODSBALB/c mice were immunized three times by intramuscular inoculations of DNA vaccine encoding of hantanvirus nucleocapsid protein alone or in combination with a plasmid expressing murine interleukin-12 (pcIL-12). Booster immunizations were employed 2 times at 2-week interval. To evaluate the humoral and cellular immune responses, antigen-specific lymphocyte proliferation and antibody production were assayed by MTT method and ELISA respectively. The level of interleukin-4 and interferon-gamma in the splenic lymphocytic cultured supernatant were detected with ELISA kit at day 5, 10, 17, 35 and 42 after primary immunization.

RESULTSAntigen-specific IgG antibodies was increased markedly at day 17 in the experiment groups and reached a plateau after day 35. As pcIL-12 co-injected, a significant inhibition of antigen-specific IgG levels was displayed over the period and the antibody mean titre was decreased to only about 1:50 at day 42 after primary immunization, significantly lower than the group immunized with pcDNA3.1 + S alone, in which the mean titre was about 1:70. Interferon-gamma was increased remarkably by the co-injection of pcIL-12 compared with the injection of pcDNA3.1 + S alone. However, the production of interleukin-4 was inhibited by pcIL-12 co-injection. Furthermore, pcIL-12 co-injection efficiently enhanced antigen-specific lymphocyte proliferation.

CONCLUSIONHumoral and cytokine responses elicited by pcDNA3.1 + S inoculation can be modulated by co-inoculation with pcIL-12 and efficiently induced Th1-dominant immune responses.

Animals ; Cytokines ; biosynthesis ; Genetic Therapy ; Hantavirus ; immunology ; Immunoglobulin G ; blood ; Immunophenotyping ; Interleukin-12 ; genetics ; Lymphocyte Activation ; Male ; Mice ; Mice, Inbred BALB C ; Nucleocapsid ; genetics ; immunology ; Vaccines, DNA ; immunology ; Viral Vaccines ; immunology

OBJECTIVETo study the mechanism and clinical effect of using the manipulatin of move, adduction, rotation method for the treatment of shoulder dislocation.

METHODSfrom January 2010 to March 2012,120 patients with shoulder dislocation admitted were randomly divided into treatment group and control group, 60 cases in each group. In the treatment group, there were 31 males and 29 females; In control group, there were 30 males and 30 females. In treatment group, 60 patients create their own "on the move, adduction, rotation manipulative treatment,the other 60 cases in control group used traditional restoration methods in wearing the traction treatment. The efficacy of two methods of treatment of shoulder dislocation were compared on reset process once successfully rate, the patient's level of pain (VAS).

RESULTSIn treatment group, restoration once successfully were in 59 cases, improvement of the pain (VAS) values was 3.76 +/- 1.05, the results were excellent in 57 cases, good in 2, poor in 1,without concurrent fractures and nerve injury, without re-dislocation after 3 months. In control group, restoration once successfully were in 50 cases, improvement of pain (VAS) values was 5.67 +/- 1.15, the results were excellent in 45 cases, good in 7, poor in 8. The reset once successfully rate,improvement of VAS values and clinical effect in treatment group were better than that of control group.

CONCLUSIONOn the move, adduction, rotation method has advantages of more wearing traction with uniform force, work together to focus, saving time and effort, easy and convenient to avoid iatrogenic injury.

Adult ; Female ; Humans ; Male ; Manipulation, Orthopedic ; methods ; Rotation ; Shoulder Dislocation ; therapy

Objective On July 6, 2010, the parents of a patient with confirmed measles reported several suspected measles patients with fever and rash in their village. An investigation was carried out to verify and understand the cause of the outbreak. Methods Several suspected cases had an onset of fever and rash in this and other neighboring villages during June 1 to August 3,2010. A confirmed case was a suspected case with measles-specific IgM identified in the serum. We conducted door-to-door visits and searched the Chinese Center for Disease Control and Prevention Information System to identify cases, also conducted a retrospective cohort study among migrant children aged 8 months-14 years to identify risk factors related to measles. Results We identified 19 measles cases (17 confirmed case, 2 suspected cases)in the village, and all of them were migrants. Children aged 1-2 years had the highest attack rate(13%). The primary case-patient had onset on the day she arrived in this village(June 4,2010). Caretakers from an unlicensed private clinic were providing service in the village but did not report the outbreak to the public health authority. The outbreak was identified only after receiving a report from the parents of one of the patients, by that time the outbreak had lasted for one month. The measles vaccine coverage rate was 81% among the 315 migrant children aged 8 months-14 years. Among the 61 unvaccinated children, those who reportedly being contacted a measles patient had a higher attack rate(14/16, 88%)than those who did not(2/45, 4.4%)(Relative risk=20, Fisher' s exact 95% confidence interval: 5.7-94). Conclusion The low measles vaccine coverage among migrant children and lack of measures taken on the incident, timely isolation diagnosis/reporting by the caretakers from the unlicensed private clinic etc. had contributed to this prolonged outbreak. Measures need to be taken to improve the immunization services for migrant populations and to enhance measles surveillance programs in the area.

Objective: To explore the effect of immunogenicity and immunizing protection of GAMA gene DNA vaccine, which was related with merozoite, ookinete and sporozoite invasion. Methods: Gene fragments were obtained using PCR technique and eukaryotic expression vector (containing immunostimulatory sequence) was built. BALB/c mice were divided into PBS control group, empty vector control group and study group and were immunized at week 0, 3 and 6 respectively. Blood was collected 2 weeks after each immunization and serum was separated to detect the IgG, IgG1 and IgG2a levels. Spleen of mice was obtained for preparation of splenic mononuclear cell and the cytokine IL-4 and IFN-γ levels were detected. Indirect immunofluorescence and western blot were employed to verify the specificity of antiserum. Sporozoite and merozoite invasion were used respectively to detect the immune protective effect 2 weeks after the third immunization. Ookinete conversion rate in vitro and oocyst numbers of mosquito stomach were observed to evaluate the transmission-blocking levels. Results: In GAMA DNA vaccine group: antiserum could be combined with recombinant protein specifically and green fluorescence signals of merozoite, ookinete and sporozoite were observable, while specific fragments and fluorescence signals were not observable in empty vector group. Compared with control group, specific IgG in DNA vaccine immunity group significantly increased (P < 0.01), and IgG1 and IgG2a all increased (P < 0.01). IL-4, IFN-γ content in study group significantly increased, compared with control group (P < 0.01). GAMA DNA vaccine immunity could not obviously block the erythrocyte-stage infection (caused by sporozoite invasion); compared with control group, liver worm load was slightly reduced (P < 0.05), and antiserum ookinete numbers (cultured in vitro) had no significant difference with oocyst numbers of mosquito stomach in DNA vaccine group. Conclusions: GAMA has good antigenicity, which could stimulate the body to produce specific immune responses; while DNA vaccine immunity could not play a good protective effect, the effect of which is only limited to the slight reduction of liver worm load, and has no obvious erythrocyte-stage protective effect and transmission-blocking effect. Therefore, trying other immunization strategies for further research on the value of GAMA (as multi-stage antigen vaccine and multi-stage combined vaccine components of the life-cycle of plasmodium) is necessary.

OBJECTIVETo analyze the results of avian influenza surveillance program in Guangzhou from 2006 to 2012 and to evaluate the risk of infections with H5, H7 and H9 subtypes avian influenza viruses.

METHODSAvian influenza surveillance system in Guangzhou consisted five components:serum surveillance on occupational population, environmental specimen surveillance of avian influenza virus, avian flu emergency surveillance, influenza viruses surveillance on ILI patient and surveillance on pneumonia of unknown causes. Hemagglutination inhibition test was conducted to detect the antibodies against H5, H7 and H9 while RT-PCR was used to test the nucleic acid of H5, H7 and H9 viruses.

RESULTSFrom 2006 to 2012, 4103 serum specimens were collected from occupational populations and the overall positive rate of H5/H7/H9 antibodies was 3.82% . The antibody positive rates for H5, H7 and H9 were 0.22% ,0.00% and 3.70% respectively. 4 serum specimens for H5 and H9 simultaneously showed antibody positive. The positive rate of H9 among occupational populations(4.21%)appeared higher than that from the control population(2.16%). 2028 specimens were collected from poultry sites and 55 samples found positive for H5 nucleic acid (positive rate:2.71%), 14 samples positive for H9 nucleic acid (positive rate:0.69%), 5 specimens, simultaneously positive for H5 and H9 nucleic acids. However, none of the samples showing H7 nucleic acid positive. From 2006 to 2012, all the tested H5/H7/H9 virus were negative from the respiratory/serum specimens among those close contacts of patients or high risk groups through the avian flu emergency surveillance program,ILI patient influenza virus surveillance programs or pneumonia of unknown causes surveillance program.

CONCLUSIONContamination of H5/H9 avian influenza virus did exist in the poultry sites in Guangzhou, especially in the wet Markets. The H5/H9 avian influenza virus caused asymptomatic infection was proved to be existed within the population exposed to the poultry, suggesting that the poultry occupational population in Guangzhou was under the risk of avian influenza virus infection.

Adult ; Animals ; China ; epidemiology ; Environmental Monitoring ; Female ; Humans ; Influenza A virus ; Influenza in Birds ; epidemiology ; Influenza, Human ; epidemiology ; prevention & control ; virology ; Male ; Middle Aged ; Occupational Exposure ; prevention & control ; Population Surveillance ; Poultry

Background: Sleep disorders are one of the earliest non-motor symptoms of Parkinson’s disease (PD). Sleep disorders could, therefore, have value for recognition and diagnosis in PD. However, no unified classification and diagnostic criteria exist to evaluate sleep disorders by polysomnography (PSG). Utilizing PSG to monitor sleep processes of patients with PD and analyze sleep disorder characteristics and their relationship with demographic parameters could aid in bridging this gap. This preliminary study aimed to evaluate the clinical characteristic of sleep disorders in PD using PSG. Methods: PSG was used to evaluate sleep disorders in 27 patients with PD and 20 healthy volunteers between August 2015 and July 2018 in Fujian Medical University Union Hospital. Total sleep time (TST), sleep efficiency (SE), total wake time, and other parameters were compared between the two groups. Finally, the correlation between sleep disorders and age, disease duration, Unified Parkinson’s Disease Rating Scale-III scores, Hoehn-Yahr stage, and levodopa dose were analyzed. The main statistical methods included Chi-square test, two independent samples t test, Fisher exact test, and Pearson correlation. Results: Sleep fragmentation in the PD group was significantly increased (74.1%) while difficulty falling asleep and early awakening were not, as compared to healthy controls. No significant differences were found in time in bed, sleep latency (SL), non-rapid eye movement (NREM) stage 1 (N1), N1%, N2, N2%, N3%, and NREM% between PD and control groups; but TST (327.96 ± 105.26 min vs. 414.67 ± 78.31 min, P = 0.003), SE (63.26% ± 14.83% vs. 76.8% ± 11.57%, P = 0.001), R N3 (20.00 [39.00] min vs. 61.50 [48.87] min, P = 0.001), NREM (262.59 ± 91.20 min vs. 337.17 ± 63.47 min, P = 0.003), rapid-eyemovement (REM) (32.50 [33.00] min vs. 85.25 [32.12] min, P < 0.001), REM% (9.56 ± 6.01 vs. 15.50 ± 4.81, P = 0.001), REM sleep latency (157.89 ± 99.04 min vs. 103.47 ± 71.70 min, P = 0.034) were significantly reduced in PD group. Conclusion This preliminary study supported that sleep fragmentation was an important clinical characteristic of sleep disorders in PD. Whether sleep fragmentation is a potential quantifiable marker in PD needs to be further investigated in the future study.