Objective:To prepare and characterize chitosan/hyaluronic acid (CS/HA) nanoparticles for miRNA-148b (miR-148b)delivery.Methods:CS/HA/miR-148b nanoparticles were prepared.The particle size,zeta potential,morphology were investigated by nano laser granulometer and TEM respectively.The encapsulation efficiency of CS/HA nanoparticles was evaluated by gel retarding analysis.The cytotoxicity and transfection efficiency of CS/HA/miR-148b nanoparticles on rat bone marrow mesenchymal stem cells (MSCs) were evaluated by CCK-8 assay,transfection assay and FCM respectively.Results:The CS/HA/miR-148b nanoparticles were discrete spherical particles with the diameter of 160 to 370 nm and zeta potential of + 15 to +41 mV.N/P ratio at 20∶1 of the nanoparticles showed the optimum encapsulation efficiency for miR-148b.CS/HA/miR-148b nanoparticles exhibited no cytotoxicity to MSCs and could deliver miR-148b to the MSCs at high transfection efficiency.Conclusion:CS/HA/miR-148b nanoparticles are safe and effective for miR-148b delivery into MSCs.

The recording and analysis for the neurons' single unit discharge is one of the important content among the comprehensive experiments in basic medicine.However,the traditional experiment cannot help the students to understand the mechanism of the action potential.According to the high comprehensive quality and high requirements of training in eight-year medical students,in the past two years,we have entrained the optogenetics into the single unit recording experiment and set up an experiment of neuronal discharge evoked by the optogenetics.In this article,we the introduce teaching design of the recording and analysis of the unit discharges induced by light genetics,sum up teaching experience and put forward our own thinking.

Massive open online courses (MOOCs) , which has caused a large scale of medical edu-cation in recent years, has led to an exploration boom in medical education. By the end of November 2014, on four large domestic and foreign MOOCs platform, a total of 178 medical related MOOCs were found, accounting for 12.2% of the total number of courses, among which public health MOOCs accounted for 44.9%. In terms of medical education, MOOCs are not only a powerful supplement of existing medical ed-ucation and can assist dissemination of medical knowledge, they can also promote pedagogy innovation and improve teaching quality to a certain extent. Moreover, the huge amounts of data collected by MOOCs can also be used to develop research of students' learning behavior. In addition, by recruiting study objects, the researchers have begun to use MOOCs supporting scientific research. As a novel educational development, MOOCs face many challenges while they bring opportuni-ties for medical education. However, active prac-tice and exploration will bring more powerful vitality for its development in the medical field.

OBJECTIVEThis study aims to evaluate the antimicrobial activity of decapeptide, a novel antimicrobial peptide, against several major cariogenic and periodontopathogenic bacteria in vitro. METHODS In this study, we investigated the antimicrobial activity of decapeptide against Streptococcus mutans (S. mutans), Streptococcus sobrinus, Lactobacillus acidophilus, Streptococcus sanguis, Streptococcus gordonii, Actinomyces viscosus, Actinomyces naeslundii, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Saccharomyces albicans in vitro using the agar diffusion method and broth dilution method. Furthermore, a time-kill kinetic study of decapeptide against S. mutans was performed.

RESULTSThe results showed that decapeptide exhibited antimicrobial activity against various oral bacteria and fungi. The minimum inhibitory concentration (MIC) of main cariogenic bacteria ranged from 62.5 μg · mL(-1) to 125 μg · mL(-1), and the MIC of periodontopathogenic bacteria tested ranged from 250 μg · mL(-1) to 1,000 μg · mL(-1). Among the bacteria tested, decapeptide had a strong inhibitory effect on cariogenic S. mutans. Results of the time-kill kinetic studies showed that decapeptide reduced the viable counts of S. mutans by more than one order of magnitude after 20 min of incubation, and thoroughly killed S. mutans after 30 min. No viable cells could be detected after 24 h of incubation.

CONCLUSIONThis study suggest that decapeptide might have potential clinical application in treating dental caries by killing S. mutans within dental plaque.

Aggregatibacter actinomycetemcomitans ; Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; Dental Caries ; Dental Plaque ; Kinetics ; Microbial Sensitivity Tests ; Mouth ; microbiology ; Porphyromonas gingivalis ; Streptococcus mutans

SUMMARY Our work focused on the studies on the expression and function of transient receptor poten -tial vanilloid subtype 1 ( TRPV1) in the submandibular gland .By using reverse transcription-polymerase chain reaction ( RT-PCR ) , Western blotting , and immunofluorescence , our data demonstrated the expression and distribution characteristics of TRPV 1 in rabbit and human submandibular glands , as well as rat submandibular gland cell line SMG-C6.Furthermore, the possible intracellular signal molecules involved in the TRPV1-modulated saliva secretion were explored .Activation of TRPV1 increased the intracellular Ca2+concentration, upregulated the expression of aquaporin 5 (AQP5), the main transpor-ter that mediate water secretion through transcellular pathway , and led to AQP5 redistribution .Extracel-lular signal-regulated kinase 1/2 ( ERK1/2 ) was involved in the TRPV1-regulated AQP5 content. Besides, TRPV1 activation also modulated the expression , distribution, and function of tight junction protein, and increased paracellular permeability .ERK1/2 and myosin light chain 2 ( MLC2 ) were responsible for the regulation of TRPV1on tight junction properties.Taken together, our work suggested that TRPV1 was a potential target to promote saliva secretion , and activation of TRPV1 might provide a new and safe therapeutic strategy to ameliorate submandibular gland hypofunction .

Objective To explore the genetic mechanism of Yang-deficiency constitution by detecting genomic copy number variations (CNVs). Methods Thirty cases of Yang-deficiency constitution and 30 cases of balanced constitution were included according to the standards of Classification and Determination of Constitution in Traditional Chinese Medicine. DNA was extracted from white blood cells in peripheral blood. A genome-wide association study was conducted by using Affymetrix SNP 6.0 platform. CNVs of each sample were analyzed using PennyCNV software. The Yang-deficiency constitution-specific copy number variation regions (CNVRs) of each autosome were identified. CNVR-related genes and their annotations were searched at online Human Genome Browser. Results The mean number of CNVs in balanced constitution group was 12.63±3.39, ranging from 8 to 20. After stepwise elimination of two Yang-deficiency constitution subjects, the mean number of CNVs in Yang-deficiency constitution group was 15.04±8.95, ranging from 2 to 38. A total of 26 CNVRs were identified from 28 Yang-deficiency constitution subjects, including 19 duplicated CNVRs, 6 deleted CNVRs, and 1 mixed type CNVR. Most CNVRs were shared by a few Yang-deficiency constitution subjects, and only 7 CNVRs were shared by more than 5 Yang-deficiency constitution subjects. The functions of representative genes in Yang-deficiency constitution-specific CNVRs were related with extracellular and intracellular signal transduction, metabolic regulation, and immune response, etc. Conclusion Yang-deficiency constitution subjects have some specific genomic CNVs, which might result in Yang-deficiency constitution phenotypes by influencing the expression of genes associated with extracellular and intracellular signal transduction, material metabolism (energy metabolism), and immune response, etc.

ObjectiveTo explore the influence of washable type subglottic attract on incidence of ventilator-associated pneumonia (VAP) in patients with mechanical ventilation. Methods356 cases in need of mechanical ventilation from July 2009 to July 2010 in our hospital were chosen as the research object.They were randomly divided into the observation group and the control group with 178 cases in each group.The control group was treated with conventional endotracheal tube for mechanical ventilation.The observation group used washable type subglottic endotracheal tube to attract for mechanical ventilation.The VAP rate for the two groups occurred during mechanical ventilation in ventilator was compared.Migration of the dominant bacteria of the subglottic secretion was detected,underwent pathogenic examination and drug sensitivity test. ResultsThe VAP rate was significantly lower in the observation group than that of the control group.186 bacteria strains were detected from subglottic secretion,and 169 were detected from lower respiratory tract. ConclusionsWashable type subglottic attract for mechanical ventilation can reduce the risk of ventilator-associated pneumonia for patients with mechanical ventilation significantly,and it is worthy of clinical application.

Objective To observe and analyze the role of different subfields of medial prefrontal cortex (mPFC) in the expression course of startle reflex.Methods 24 healthy male British kind of albino guinea pigs were randomly divided into 4 groups:anterior cingulated cortex lesion ( n =6) and sham-lesion ( n =6) ( Experiment 1 ) ; prelimbic cortex lesion/joint lesion of prelimbic cortex and anterior cingulated cortex(n=6) and sham-lesion ( n =6) ( Experiment 2 ).The animals were injected lidocaine ( lesion ) or physiological saline ( sham-lesion ).Each group received paired training of conditioned stimulus( CS,a tone) and unconditioned stimulus (US,a air puff),to observe the acoustic startle reflex(ASR) change of these groups.Results As the results of experiment 1 suggested,SR rate did not change significantly after anterior cingulated cortex lesion ( time effect:F =15.421,P =0.098 ; group effect:F =14.753,P =0.084).As the results of experiment 2 suggested,SR rate did not change significantly after prelimbic cortex lesion ( time effect:F =14.975,P =0.178 ; group effect:F =18.643,P =0.089).When prelimbic cortex and anterior cingulated cortex were lesioned at the same time,SR rate declined significantly and didn ' t recover with the following training ( group effect:F =67.743,P =0.009 ).ConclusionLesions of the prelimbic cortex and anterior cingulated cortex in mPFC cause the significantly decline of acoustic startle reflex( ASR),which don' t recover with the following training.This study indicates that mPFC involves in the regulation of ASR,but the regulation mechanism needs to be discussed.

Objective To observe the effects of 860 MHz microwave radiation on an established dual task model of trace and delay eyeblink conditioning in guinea pigs.Methods Twenty-four guinea pigs with an established dual task model of trace and delay eyeblink conditioning were assigned randomly into four groups : a microwave-exposed 1 h group, a microwave-exposed 20 min group, a sham-exposed group and a normal control group.The guinea pigs in the 1 h and 20 min groups were irradiated on the head daily for 3 days using 860 MHz electromagnetic radiation at a power density of 1 mW/cm2 for 1 h and for 20 min, respectively. After radiation the guinea pigs were trained with classical dual task eyeblink conditioning.Results Compared with the normal control group, the behavioral parameters (acquisition rate and peak amplitude of trace and delay eyeblink) of guinea pigs in the microwave-exposed 1 h group had decreased significantly with no obvious change in latency. The behavioral parameters of guinea pigs in the microwave-exposed 20 min group, the sham-exposed group and the normal control group showed no obvious change.Conclusions Microwave radiation at 860 MHz and 1.0 mW/cm2 for 1 h can cause changes in dual trace and delay eyeblink conditioning in guinea pigs and decrease learning and memory capacity.

Objective:To determine the status of glucose intolerance in breast cancer patients without DM history after combined treatment with surgery and/or chemotherapy through an oral glucose tolerance test (OGTT). Methods:All 121 breast cancer patients more than 3 months after combined treatments with surgery and/or chemotherapy and without the diagnosis of diabetes underwent OGTT and fasting. Then, 2 h glucose levels were measured to identify glucose tolerance and diabetes. Meanwhile, six patients with a history of diagnosed diabetes did not undergo OGTT. Results:The median ages of all breast cancer patients and the mean duration after combined treatments with surgery and/or chemotherapy were 50.4 years and 19 months, respectively. Among the 121 breast cancer pa-tients without the history of diabetes, the incidences of diabetes, prediabetes, and normal glucose intolerance were 19.8%(24 cases), 45.5%(55 cases) and 34.7%(42 cases), respectively. Among all breast cancer patients, the incidences of previously diagnosed diabetes, undiagnosed diabetes, and prediabetes were 4.72%, 18.9%, and 43.3%, respectively. The ratio of previously undiagnosed diabetes was about 80%. About 80.0% of undiagnosed diabetes and 74.5% of prediabetes met the criteria for elevated 2 h plasma glucose levels through OGTT instead of elevated fasting glucose levels. Conclusion: Breast cancer patients during follow-up after combined treat-ments with surgery and/or chemotherapy highly suffer from glucose intolerance, with high incidences of undiagnosed diabetes and pre-diabetes. OGTT should be made for breast cancer patients after combined treatments for early diagnosis, prevention, and treatment of di-abetes.