[Application of tracheotomy in the treatment of severe cases of COVID-19]

Objective: To discuss the the effects, indications and protective measures of tracheotomy for severe cases of coronavirus disease 2019 (COVID-19) patients. Methods: A retrospectively analysis was conducted to explore the clinical data of COVID-19 patients who received tracheotomy in February to March 2020, and descriptive statistics were used to analyze the indication of tracheotomy, particularity of intraoperative treatment and protective measures. Results: A total of 4 cases were included in this article. All patients were successfully operated. One case had postoperative incision continuous bleeding, there were not other complications and nosocomial infection among the medical staff. The patient's condition was relieved in different degrees after the operation, who remained hospitalized. Conclusion: Tracheotomy for severe cases of COVID-19 can achieve certain curative effect, but the occurrence of tracheotomy related complications and nosocomial infection should be effectively controlled, and the risk benefit ratio of tracheotomy should be carefully weighed before surgery.

[Application of tracheotomy in the treatment of severe cases of COVID-19]

Objective: Todiscuss the the effects, indications and protective measures of tracheotomy for severe cases of 2019 novel corona virus disease(COVID-19)patients. Methods: A retrospectively analyze was conducted to explore the clinical data of ofCOVID-19 patients who received tracheotomy in February to March 2020,descriptive statistics were used to analyze the indication of tracheotomy, particularity of intraoperative treatment and protective measures. Results: A total of 4 cases were included in this article, 3 cases were successfully operated, 1 case of postoperative incision continuous bleeding, there were not other complications and nosocomial infection among the medical staff.the patient's condition was relieved in different degrees after the operation, who remain hospitalized. Conclusion: Tracheotomy for severe cases of COVID-19 can achieve certain curative effect, but the occurrence of tracheotomy related complicationsand nosocomial infection should be effectively controlled, and the risk benefit ratio of tracheotomy should be carefully weighed before surgery.

[Expression and significance of polymeric immunoglobulin receptor in nasal polyps]

Objective:To explore the expression of polymeric immunoglobulin receptor in nasal polyps of patients with chronic rhinosinusitis with nasal polyps, and to investigateits relationship with the pathogenesis of nasal polyps. Method:Thirty-six specimens of nasal polyps were harvested patients were selected for the control group who had operation of nasal septal construction in the corresponding time period. The pIgR and IgA expression in nasal polyps and normal nasal inferior turbinate mucosa were detected by immunohistochemistry，and the real-time reverse transcription（RT-PCR） were used to detect the level of pIgR，IgA，RORc and Foxp3 mRNA expression in nasal polyps and normal nasal inferior turbinate mucosa. The association between pIgR mRNA and their association with the number of EOS，RORc mRNA，Foxp3 mRNA were analyzed，respectively． Result:The expression of pIgR in the nasal polyps was significantly lowerer than that in control group, and the result was statistically significant(P<0.05)；Compared with nasal polyps with no eosinophils, the expression levels of pIgR in the nasal polyps with eosinophils was lower\, and the result was statistically significant(P<0.05).The expression of IgA in the nasal polyps was significantly higherthan that in control , and the result was statistically significant(P<0.05).Compared with control, the mRNA expression of pIgR and Foxp3 in the nasal polyps were significantly lower，while the expression levels of IgA mRNA and Foxp3 mRNA in the nasal polyps was significantly higher compared to controls, and the result was statistically significant(P<0.05).In nasal polyps ,pIgR mRNA expression was correlated with RORc mRNA (P<0.05，r=-0.79)，and there was no correlation between pIgR mRNA and Foxp3 mRNA（P>0.05，r=0.36）. Conclusion:It was proved that pIgR down-regulation play an important role in the development of nasal polyps．.

Determination of benzo[α]pyrene in edible oil using tetraoxocalix[2]arene[2]triazine bonded silica SPE sorbent

Benzo[α]pyrene (BaP) is a well-known carcinogen in edible oil. In this study, a method combined solid-phase extraction (SPE) with fluorescent detection was developed using tetraoxocalix[2]arene[2]triazine sorbent (SiO₂-OCA) for the clean-up and enrichment of BaP. The interaction between SiO₂-OCA and BaP involves a donor-acceptor complex mechanism. The experimental procedure was as follows: BaP was extracted from edible oil with DMF/H₂O (9:1, v/v). Then, the ratio of DMF/H₂O was adjusted to 1:2 prior to SPE. The final concentrate was analysed using a fluorescence detector at excitation and emission wavelengths of 255 and 420 nm. The method was fully validated. The linearity was in the range of 0.1-100 μg kg^-1 with a coefficient of 0.999. The limits of detection and quantification were 0.03 and 0.1 μg kg^-1, respectively. The average recoveries were in the range of 88.0 - 122.3%. The intraday and interday precisions were 6.8% and 9.2%, respectively. Compared with other methods, the method reported in this article shows a good detection limit, high reproducibility and recovery and linearity over a broad concentration range. This established method was also applied to evaluate real samples. The concentration of six tested samples was below 5 μg kg^-1.

[Pressor effect of substance P applied to the pressor area of ventral surface of medulla oblongata and the underlying mechanism in rabbits]

Experiments were performed on urethane anesthetized and artificially ventilated rabbits. The results were as follows. Application of substance P (SP) to the pressor area of ventral surface of medulla oblongata (VSMp) elicited a dose-dependent increase in blood pressure (BP), but no significant change in heart rate. The pressor response of SP was blocked by pretreatment with SP receptor antagonist (DSP) in VSMp. Application of DSP alone to VSMp elicited a significant decrease in BP. The pressor response of SP was attenuated when VSMp was pretreated with phentolamine or prazosine, whereas pretreatment with yohimbin or propranolol was without effect. Application of SP to VSMp elicited an increase in renal sympathetic nerve discharge (RSND) in association with pressor response; both these responses were blocked by pretreatment with DSP in VSMp. Application of DSP alone to VSMp elicited a significant decrease in RSND and BP. The above results indicate that SP has a pressor effect in VSMp due to activation of SP receptor mediated by alpha 1-receptor. The pressor effect of SP may be mainly due to an increase of peripheral vascular resistance induced by the augmented sympathetic nerve activity. In summary, it appears that endogenous SP in VSMp plays an important role in maintaining sympathetic tone and BP level.