Comparative study of three scores in predicting the death risk of severe burn patients / 中华烧伤杂志

Objective: To explore the predictive values of the modified Baux score, Belgian Outcome in Burn Injury score, and Ryan score on the death risk of severe burn patients. Methods: A retrospective case series study was conducted. From February 2018 to November 2019, 260 severe burn patients who met the inclusion criteria were admitted to the Department of Burns of the First Affiliated Hospital of Nanchang University, including 158 males and 102 females, aged 36 (3, 53) years. According to the final outcome, the patients were divided into survival group (n=229) and death group (n=31). Data of patients were compared and statistically analyzed with chi-square test or Mann-Whitney U test between the two groups, including the gender, age, cause of burn, site of burn, total burn area, depth of burn, combined inhalation injury, and combined underlying diseases on admission, and the modified Baux score, Belgian Outcome in Burn Injury score, and Ryan score calculated based on part of the aforementioned data. The Kendall tau-b coefficient method was used to analyze the consistency of the above-mentioned three scores in 260 severe burn patients. The receiver operating characteristic (ROC) curves of the above-mentioned three scores predicting the death risk of 260 severe burn patients were drawn, and the area under the curve (AUC), the optimal threshold, and the sensitivity and specificity under the optimal threshold were calculated. The quality of AUC of the above-mentioned three scores was compared by Delong test. Results: The gender, site of burn, and depth of burn of patients between the two groups were all similar (P>0.05). The age, total burn area, proportion of flame burn, proportion of combined inhalation injury, and proportion of combined underlying diseases of patients in death group were significantly higher than those in survival group (with Z values of 5.53 and 17.78, respectively, χ2 values of 16.23, 15.89, and 17.78, respectively, P<0.01); the modified Baux score, Belgian Outcome in Burn Injury score, and Ryan score of patients in death group were 142 (115, 155), 7 (5, 7), 2 (2, 3), all significantly higher than 64 (27, 87), 1 (0, 3), 0 (0, 1) in survival group (with Z values of 7.91, 7.64, and 7.61, respectively, P<0.01). In 260 severe burn patients, the results between the modified Baux score and Ryan score, modified Baux score and Belgian Outcome in Burn Injury score, Ryan score and Belgian Outcome in Burn Injury score were significantly consistent (with Kendall tau-b coefficients of 0.75, 0.71, and 0.86, respectively, P<0.01). The AUCs of ROC curves of the modified Baux score, Belgian Outcome in Burn Injury score, and Ryan score for predicting the death risk of 260 severe burn patients were 0.92, 0.89, and 0.85, respectively (with 95% confidence intervals of 0.86-0.98, 0.83-0.95, and 0.78-0.93, respectively, P<0.01); the optimal thresholds were 106.5, 4.5, and 1.5 points, respectively; the sensitivity under the optimal threshold were 88.5%, 76.9%, and 73.1%, respectively, and the specificity under the optimal threshold were 88.5%, 87.2%, and 86.3%, respectively. The modified Baux score was similar to Belgian Outcome in Burn Injury score in the AUC quality (z=1.25, P>0.05), which were both significantly better than the AUC quality of Ryan score (with z values of 2.35 and 2.11, respectively, P<0.05). Conclusions: The modified Baux score, Belgian Outcome in Burn Injury score, and Ryan score have good ability in predicting the death risk of severe burn patients. From the perspective of clinical practice, the modified Baux score is more suitable as a predictive tool for the prognosis of severe burn patients.

Visual detection of H1 subtype and identification of N1, N2 subtype of avian influenza virus by reverse transcription loop-mediated isothermal amplification assay / 病毒学报

In order to visually detect H1, N1 and N2 subtype of avian influenza virus (AIV), three reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays were developed. According to the sequences of AIV gene available in GenBank, three degenerate primer sets specific to HA gene of H1 subtype AIV, NA gene of N1 and N2 subtype AIV were designed, and the reaction conditions were optimized. The results showed that all the assays had no cross-reaction with other subtype AIV and other avian respiratory pathogens, and the detection limit was higher than that of conventional RT-PCR. These assays were performed in water bath within 50 minutes. Without opening tube, the amplification result could be directly determined by inspecting the color change of reaction system as long as these assays were fin-ished. Fourteen specimens of H1N1 subtype and eight specimens of H1N2 subtype of AIV were identified from the 120 clinical samples by RT-LAMP assays developed, which was consistent with that of virus isolation. These results suggested that the three newly developed RT-LAMEP assays were simple, specific and sensitive and had potential for visual detection of H1, N1 and N2 subtype of AIV in field.

Development of a GeXP assay for simultaneous differentiation of six chicken respiratory viruses / 病毒学报

A GeXP based multiplex PCR assay was developed to simultaneously detect six different chicken respiratory viruses including H5, H7, H9 subtypes of avian influenza virus(AIV), new castle disease virus (NDV), infectious bronchitis virus(IBV) and infectious laryngotracheitis virus(ILTV). According to the conserved sequences of genes of each pathogen, seven pairs of specific primers were designed, and the reaction conditions were optimized. The specificity and accuracy of GeXP were examined using samples of single and mixed infections of virus. The sensitivity was evaluated by performing the assay on serial 10-fold dilutions of cloned plasmids. To further evaluate the reliability, thirty-four clinical samples were detected by GeXP. The corresponding specific fragments of genes were amplified. The detection limit of GeXP was 10(2) copies/microL when all of 7 pre-mixed plasmids containing target genes of six chicken respiratory viruses were present. In the detection of thirty-four clinical samples, the results of GeXP were accorded with the viral isolation completely. In conclusion, this GeXP assay is a rapid, specific, sensitive and high-throughput method for the detection of chicken respiratory virus infections. It can be applied in rapid differential diagnosis for clinical samples, and also provide an effective tool to prevent and control chicken respiratory diseases with similar clinical symptoms.