Quartz Crystal Microbalance Technology Coupled with Impedance for the Dynamic Monitoring of the Cardiomyocyte Beating Function and Drug Screening.

The main sensing techniques used to study myocardial pulsation are electrical impedance sensing (EIS) and by quartz crystal microbalance (QCM). While electrical impedance technology is the gold standard for the study of myocardial pulsation, the clinical application of drugs is being followed up in real time additionally, thus, QCM technology needs to be further developed as a very important class of quality sensor technology. Moreover, the application of EIS, in combination with the QCM, for monitoring myocardial pulsation, has been rarely reported. In this paper, a series of cell growth and adhesion conditions were optimized using rat primary cardiomyocytes, and QCM was used in combination with EIS to monitor the adhesion and the myocardial pulsation ability of the cells in real time. Furthermore, cardiomyocytes that adhered to the QCM and EIS were treated with isoprenaline (ISO), a positive inotropic drug, and verapamil (VRP), a negative inotropic drug. Next, the cell index (CI)-time (T) plots, beating amplitude (BA) and beating rate (BR) of the cardiomyocytes were calculated and changes in these parameters, before and after, dosing were evaluated. The results showed that the QCM technique results were not only consistent with the results obtained with EIS, but also that the QCM technique had a certain degree of sensitivity for the calculation of cardiomyocyte beating. Thus, our findings validate the reliability and validity of the QCM technique for measuring cardiomyocyte beating and drug testing. We hope that further studies would evaluate the application of the QCM technology for clinical use.

[TLR-4 involvement in pyroptosis of mice with pulmonary inflammation infected by Actinobacillus pleuropneumoniae].

OBJECTIVE: Pyroptosis is a caspase-1 dependent programmed cell death and involves pathogenesis of infectious diseases by releasing many pro-inflammatory cytokines to induced inflammation. TLR-4 plays an important role in mediating pathogenesis of some infectious diseases. In this study, we detected the expression of TLR-4 and some molecules (e. g caspase-1, TNF-α, IL-1ß, IL-6, IL-18 ) related with pyroptosis to determine its involvement and mechanisms of pulmonary inflammation in mice infected by A. pleuropneumoniae. METHODS: Mice were intranasally infected by A. pleuropneumoniae and killed 48 hours post infection. Pulmonary gross lesion and histological pathology by H-E were observed. Expression levels of caspase-1 , caspase-3, TNF-α, IL-1ß, IL-6, IL-18, and TLR-4 in lung of mice were detected by RT-PCR and qPCR. RESULTS: Serious pulmonary hemorrhage and inflammation in infected mice were observed. Expression levels of caspase-1, caspase-3, TNF-α, IL-1ß, IL-6, IL-18 and TLR-4 increased, and expression levels of caspase-3 were not changed in lung of infected mice. CONCLUSION: TLR-4 might be involved in pulmonary inflammation of mice infected by A. pleuropneumoniae. After induced by activated TLR-4 some cells in this lesion expressed pro-inflammatory cytokines. These cytokines would induce pulmonary inflammation. This lesion might involve pyroptosis with caspase-1 expression.

Vaccination of goats with 31 kDa and 32 kDa Schistosoma japonicum antigens by DNA priming and protein boosting.

Two Schistosoma japonicum vaccine candidate antigens Sj 31 and Sj 32, which have shown particular promise to induce protective immunity in mice, were used to immunize goats by using a DNA priming-protein boosting strategy in present work. DNA vaccine formulations of the two antigens (VRSj31 and VRSj32) were produced and injected intramuscularly twice at a 2-week interval and then recombinant proteins (rSj31 and rSj32) together with Freund Complete Adjuvant (FCA) were used to boost the goats. The experiment was repeated in different batche cercariae. A strong anamnestic antibody response was induced after boost. A significant reduction of liver egg counts and miracidial hatching was showed in both experiments. Significant protections against challenge infection were elicited with 31.6% of percentage reduction for worm recovery in the second experiment and 20.9% in the first experiment, respectively.

[DNA vaccine encoding SjIR3 induces partial immune protection against Schistosoma japonicum in mice].

OBJECTIVE: To detect the protection in mice induced by DNA vaccine encoding SjIR3 against Schistosoma japonicum (Sj). METHODS: Sj1R3 was amplified by PCR with specific primers and linked to T vector. The reconstructed plasmid was digested by Xho I and BamH I. The target segments were collected and inserted into pcDNA3.0 to construct DNA vaccine SjIR3/pC. Fifty-four female mice were divided into 3 groups: groups A and B received normal saline and pcDNA3.0 respectively as controls, and group C was immunized with SjIR3/pC. All the mice were injected three times with an interval of two weeks. Sera were collected before each inoculation and before challenge infection. Six mice from each group were sacrificed 2 weeks after the final inoculation and spleen cells were collected. Serum IgG was detected by ELISA and the proliferation activity of spleen T lymphocytes induced by ConA or rSjIR3 was detected by MTT assay. The remaining mice were infected by (40+/-1) Sj cercariae per mouse 2 weeks after the final inoculation. Forty-five days later, mice were sacrificed and perfused, numbers of adult worms and of eggs in liver tissue were counted. RESULTS: ELISA showed no significant change of serum IgG level in groups A and B, but considerable increase in group C (0.78+/-0.05) (P<0.01). The proliferation activity of spleen T lymphocytes increased with the induction of ConA or recombinant protein rSjIR3 after the final inoculation. The A570 was 0.57+/-0.02 and 0.68+/-0.01 respectively, showing a significant difference in comparison to the groups A and B (P<0.01). The worm reduction rate and the egg reduction rate in group C were 29.42% and 36.56% respectively. CONCLUSION: DNA vaccine encoding SjIR3 induces humoral and cell-mediated immune response, and shows partial immune protection against Schistosoma japonicum.

[Intranasal or intragastric vaccination of mice with recombinant Schistosoma japonicum ferritin induces immune protection against challenge infection].

OBJECTIVE: To test the immune protection against challenge infection in mice vaccinated intranasally or intragastrically with recombinant Schistosoma japonicum (S.j) Ferritin (rSjFer). METHODS: Mice were divided into 8 groups each with 10 mice. They were immunized intragastically with rSjFer, CTB, rSjFer + CTB and intranasally with rSjFer, CTB and rSjFer + CTB respectively. PBS was used intragastically or intranasally as control groups. The mice were challenged with 40 +/- 1 S. j cercariae per mouse 2 wk after the third vaccinization. Forty-five days later, mice were killed and perfused, and the adult worms and eggs were counted. Serum and fecal samples were obtained before the first immunization and the challenge infection. IgA and IgG in sera and sIgA in feces were detected by ELISA. RESULTS: The worm reduction rate was 3.98%, 3.77%, 25.57% in the intragastric vaccination groups and 7.59%, 4.50%, 33.35% in the intranasal vaccination groups respectively. The egg reduction rate was 3.76%, 2.46%, 34.75% and 4.40%, 0.06%, 60.10% respectively. CONCLUSION: This study showed that a significant immune protection against Schistosoma japonicum infection was induced by mucosal (intranasal and intragastic) vaccination with rSjFer.