Objective:To investigate the efficacy of intravenous combined with aerosol inhalation of polymyxin B for the treatment of pneumonia caused by multidrug-resistant Gram-negative (G -) bacteria. Methods:A observational study was conducted. The clinical data of 45 patients with pneumonia due to multidrug-resistant G - bacteria admitted to intensive care unit of Fujian Medical University Union Hospital from January to October in 2020 were analyzed. According to the different use methods of polymyxin B, 25 patients who received single intravenous drip (the first dose was 2.0 mg/kg, then 1.25 mg/kg, once every 12 hours) from January to April in 2020 were enrolled in the routine group, and 20 patients who received intravenous drip combined with aerosol inhalation (25 mg once every 12 hours, sputum in the airway was sucked and then sprayed aerosol) from May to October in 2020 were enrolled in the combination group. After the treatment course of polymyxin B, the total bacterial clearance rate, total clinical efficiency rate, recovery time of body temperature, time of bacterial clearance and the change of serum procalcitonin (PCT) level before and after treatment were compared between the two groups. Moreover, the incidence of adverse reactions during treatment in the two groups was observed. Results:The results of sputum culture in the routine group were Acinetobacter baumannii in 13 patients, Klebsiella pneumoniae in 5 patients, Pseudomonas aeruginosa in 6 patients, Enterobacter cloacae in 1 patient; the sputum culture results of the combination group showed that there were 5 patients of Acinetobacter baumannii, 9 Klebsiella pneumoniae and 6 Pseudomonas aeruginosa. There was no significant difference in the results of sputum culture between the two groups ( P > 0.05). The total bacterial clearance rate and the total clinical efficiency rate of the combination group were significantly higher than those in the routine group (total bacterial clearance rate: 70.0% vs. 40.0%, total clinical efficiency rate: 75.0% vs. 40.0%, both P < 0.05). The recovery time of body temperature and the time of bacterial clearance of the combination group were significantly shorter than those in the routine group [recovery time of body temperature (days): 6.0±3.9 vs. 10.2±7.3, time of bacterial clearance (days): 6.1±5.2 vs. 11.5±6.8, both P < 0.05]. No significant difference was found in serum PCT level before treatment between the two group. There was no significant difference in serum PCT level before and after treatment in the routine group [μg/L: 0.85 (0.44, 2.87) vs. 1.43 (0.76, 5.30), P > 0.05]. The serum PCT level after treatment in the combination group was significantly lower than that before treatment [μg/L: 0.27 (0.10, 0.70) vs. 0.91 (0.32, 3.53), P < 0.05], and it was significantly lower than that in the routine group [μg/L: 0.27 (0.10, 0.70) vs. 0.85 (0.44, 2.87), P < 0.01]. The incidence of renal toxicity of polymyxin B between the combination group and the routine group was not significantly different (5.0% vs. 4.0%, P > 0.05). Conclusions:The efficacy of intravenous combined with aerosol inhalation of polymyxin B for the treatment of pneumonia due to multidrug-resistant G - bacteria is better than that of intravenous drip of polymyxin B only. The aerosolized polymyxin B will not increase the risk of renal injury.

Objective:To explore the relationship between CDKN1B expression and clinicopathological features in colorectal cancer.Methods:Human Protein Atlas (HPA) database and Gene Expression Profiling Interactive Analysis (GEPIA) database were used to analyze the expression of CDKN1B in colorectal cancer tissues and its relationship with the prognosis of colorectal cancer. The data of 98 patients with colorectal cancer who underwent surgery from January 2020 to December 2021 at Yixing Clinical College of Yangzhou University Medical School were retrospectively analyzed, and pathological specimens were collected. Immunohistochemistry method was used to detect CDKN1B protein expression level in colorectal cancer and paracancerous normal tissues (2 cm from the tumor site) and the correlation of CDNK1B expression with clinicopathological characteristics was analyzed.Results:The results of bioinfomatics analysis and the prediction from HPA database and GEPIA database suggested that the expression level of CDKN1B in colorectal cancer was lower than that in the normal colorectal tissues; In HPA database, the 5-year overall survival rate of patients in the CDKN1B high expression (425 cases) was higher than that of those in the CDKN1B low expression (172 cases) (65% vs.51%), and the difference in the overall survival of both group was statistically significant ( P < 0.001). GEPIA database staging module analysis showed that CDKN1B gene expression level was correlated with the pathological stage of patients with colorectal cancer ( P = 0.033). Immunohistochemistry analysis showed that CDKN1B expression was localized in the nucleus and cytoplasm. The proportion of patients with CDKN1B high expression in colorectal cancer tissues was lower than that in paracancerous normal tissues [18.37% (18/98) vs. 90.82% (89/98), P < 0.01]. The proportion of CDKN1B high expression in cancer tissues of colorectal cancer patients with poor differentiation [poor differentiation vs. high-middle differentiation: 3.70% (1/27) vs. 23.94% (17/71)], lymph node metastasis [metastasis vs. non-metastasis: 6.38% (3/53) vs. 29.41% (15/45)], TNM higher stage [stage Ⅳ vs. Ⅲ vs. Ⅱ vs. Ⅰ: 5.00% (1/20) vs. 13.95% (3/33) vs. 20.59% (8/30) vs. 36.36% (6/15)] was lower (all P < 0.05), while there were no statistically significant differences in the proportion of patients with CDKMB high expression in colorectal cancer tissues among different subgroups stratified by gender, age and tumor size (all P > 0.05). Conclusions:CDKN1B is mainly expressed in the nucleus and cytoplasm, and is lowly expressed in colorectal cancer. The lower CDKN1B expression may indicate the poorer prognosis of patients. CDKN1B can be used as a marker for clinical diagnosis, treatment and prognosis evaluation of colorectal cancer.