High-flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary disease patients after extubation: a multicenter, randomized controlled trial.

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy is being increasingly used to prevent post-extubation hypoxemic respiratory failure and reintubation. However, evidence to support the use of HFNC in chronic obstructive pulmonary disease (COPD) patients with hypercapnic respiratory failure after extubation is limited. This study was conducted to test if HFNC is non-inferior to non-invasive ventilation (NIV) in preventing post-extubation treatment failure in COPD patients previously intubated for hypercapnic respiratory failure. METHODS: COPD patients with hypercapnic respiratory failure who were already receiving invasive ventilation were randomized to HFNC or NIV at extubation at two large tertiary academic teaching hospitals. The primary endpoint was treatment failure, defined as either resumption of invasive ventilation or switching to the other study treatment modality (NIV for patients in the NFNC group or vice versa). RESULTS: Ninety-six patients were randomly assigned to the HFNC group or NIV group. After secondary exclusion, 44 patients in the HFNC group and 42 patients in the NIV group were included in the analysis. The treatment failure rate in the HFNC group was 22.7% and 28.6% in the NIV group-risk difference of - 5.8% (95% CI, - 23.8-12.4%, p = 0.535), which was significantly lower than the non-inferior margin of 9%. Analysis of the causes of treatment failure showed that treatment intolerance in the HFNC group was significantly lower than that in the NIV group, with a risk difference of - 50.0% (95% CI, - 74.6 to - 12.9%, p = 0.015). One hour after extubation, the mean respiratory rates of both groups were faster than their baseline levels before extubation (p < 0.050). Twenty-four hours after extubation, the respiratory rate of the HFNC group had returned to baseline, but the NIV group was still higher than the baseline. Forty-eight hours after extubation, the respiratory rates of both groups were not significantly different from the baseline. The average number of daily airway care interventions in the NIV group was 7 (5-9.3), which was significantly higher than 6 (4-7) times in the HFNC group (p = 0.006). The comfort score and incidence of nasal and facial skin breakdown of the HFNC group was also significantly better than that of the NIV group [7 (6-8) vs 5 (4-7), P < 0.001] and [0 vs 9.6%, p = 0.027], respectively. CONCLUSION: Among COPD patients with severe hypercapnic respiratory failure who received invasive ventilation, the use of HFNC after extubation did not result in increased rates of treatment failure compared with NIV. HFNC also had better tolerance and comfort than NIV. TRIAL REGISTRATION: chictr.org ( ChiCTR1800018530 ). Registered on 22 September 2018, http://www.chictr.org.cn/usercenter.aspx.

Recombinant Porcine Interferon Alpha Enhances Immune Responses to Killed Porcine Reproductive and Respiratory Syndrome Virus Vaccine in Pigs.

In this study, the immunoadjuvant effects of recombinant porcine interferon alpha (rPoIFNα) on the killed virus vaccine (KV) of porcine reproductive and respiratory syndrome virus (PRRSV) in pigs were investigated. The experimental pigs were divided into six groups, including normal control group, rPoIFNα control group, PRRSV KV control group, KV+40,000 U rPoIFNα immunization group, KV+400,000 U rPoIFNα immunization group, and KV+4,000,000 U rPoIFNα immunization group. The experimental pigs were boosted immunized on the 28th day after the initial immunization, and the heparinized blood and serum samples were collected at different time points of these two immunizations to detect and evaluate the immune responses of pigs after immunization by ELISA assay, neutralization assay, flow cytometry, and so on. The results showed that the proportion of the levels of PRRSV-specific antibodies, neutralizing antibodies, stimulation index, IL-4, IFN-γ, and lymphocytes within the groups immunized with KV+rPoIFNα were significantly higher than that group immunized with KV alone. The humoral and cellular immune responses in pigs were markedly enhanced by rPoIFNα after the coadministration with KV vaccine. Therefore, we tentatively think that rPoIFNα is a potential immune promoter with prospects for future applications in the pig industry.

Enhancing immunogenicity and protective efficacy of inactivated avian influenza H9N2vaccine with recombinant chicken IFN-α in chicken.

Control of currently circulating re-assorted low-pathogenicity avian influenza (LPAI) H9N2 is a major concern for both animal and human health. Thus, an improved LPAI H9N2 vaccination strategy is needed to induce complete immunity in chickens against LPAI H9N2 virus strains. Cytokines play a crucial role in mounting both the type and extent of an immune response generated following infection with a pathogen or after vaccination. To improve the efficacy of inactivated LPAI H9N2 vaccine, prokaryotic expression recombination chicken interferon-α (rchIFN-α) was used as vaccine adjuvant.In this study chIFN-α was used as adjuvant in inactivated AI H9N2 vaccine, modulated the immune response of chickens against the vaccine antigen through enhanced humoral and Th1-biased cell-mediated immunity, compared to chickens that received single AI H9N2 vaccine. To further test the protective efficacy of this improved vaccination regimen, immunized chickens were challenged with a high dose of LPAI H9N2 virus. Combined administration rchIFN-α showed markedly enhanced protection compared to single administration of the vaccine, as determined by mortality, clinical severity, and feed and water intake. This enhancement of protective immunity was further confirmed by reduced rectal shedding and replication of AIV H9N2 in challenged chickens. Our results indicate the value of combined administration of rchIFN-α to generate an effective immunization strategy in chickens against LPAI H9N2.

[Establishment and preliminary application of a quantitative real-time PCR method for detecting the transcriptions of Th1/Th2 cytokines in RAW264.7 cells].

OBJECTIVE: To establish a quantitative real-time PCR method to detect the transcriptions of Th1/Th2 cytokines in RAW264.7 cells. METHODS: The specific primers were designed according to the sequences of TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10 and ß-actin in GenBank database. Total RNA was extracted from RAW264.7 cells, and then was reverse-transcriped into cDNA, which was established as a positive standard template of the quantitative real-time PCR method. The established method was used to detect the cytokine transcriptions in RAW264.7 cells infected with Brucella abortus S2308. RESULTS: Cytokine genes above had a good linear relationship (R(2);≥ 0.982) with the detection limit of 10(2); copies/µL standard samples. The established quantitative real-time PCR method showed high specificity, sensitivity, and single melting peak for every cytokine. CONCLUSION: The quantitative real-time PCR method for detecting the transcription levels of cytokine Th1 and Th2 of macrophage RAW264.7 cells was established successfully.

[Development of the disposable cannula for endoscope].

To introduce a kind of disposable double-channel cannula made by silica gel which is used for proctosigmoidoscopy, in coordination with rigid-tubing endoscope. There are kinds of characters for this cannula: small caliber, no toxic side effect, high degree of comfort, user-friendly, low system cost., etc.