Clinical analysis of colistin sulfate in the treatment of pneumonia caused by carbapenem-resistant Gram-negative bacteria

BACKGROUND Multidrug-resistant Gram-negative bacteria,exacerbated by excessive use of antimicrobials and immunosuppressants,are a major health threat.AIM To study the clinical efficacy and safety of colistin sulfate in the treatment of carbapenem-resistant Gram-negative bacilli-induced pneumonia,and to provide theoretical reference for clinical diagnosis and treatment.METHODS This retrospective analysis involved 54 patients with Gram-negative bacilli pneumonia admitted to intensive care unit of The General Hospital of the Northern Theater Command of the People's Liberation Army of China from August 2020 to June 2022.After bacteriological culture,the patients'airway secretions were collected to confirm the presence of Gram-negative bacilli.The patients were divided into the experimental and control groups according to the medication used.The research group consisted of 28 patients who received polymyxin sulfate combined with other drugs through intravenous,nebulization,or intravenous combined with nebulization,with a daily dosage of 1.5–3.0 million units.The control group consisted of 26 patients who received standard dosages of other antibiotics(including sulbactam sodium for injection,cefoperazone sodium sulbactam for injection,tigecycline,meropenem,or vaborbactam).RESULTS Of the 28 patients included in the research group,26 patients showed improvement,treatment was ineffective for two patients,and one patient died,with the treatment efficacy rate of 92.82%.Of the 26 patients in the control group,18 patients improved,treatment was ineffective for eight patients,and two patients died,with the treatment efficacy rate of 54.9%;significant difference was observed between the two groups(P<0.05).The levels of white blood cell(WBC),procalcitonin(PCT),and C-reactive protein(CRP)in both groups were significantly lower after treatment than before treatment(P<0.05),and the levels of WBC,PCT,and CRP in the research group were significantly lower than those in the control group(P<0.05).Compared with before treatment,there were no significant changes in aspartate aminotransferase,creatinine,and glomerular filtration rate in both groups,while total bilirubin and alanine aminotransferase decreased after treatment(P<0.05)with no difference between the groups.In patients with good clinical outcomes,the sequential organ failure assessment(SOFA)score was low when treated with inhaled polymyxin sulfate,and specific antibiotic treatment did not improve the outcome.Sepsis and septic shock as well as a low SOFA score were independent factors associated with good clinical outcomes.CONCLUSION Polymyxin sulfate has a significant effect on the treatment of patients with multiple drug-resistant Gram-negative bacilli pneumonia and other infections in the lungs and is safe and reliable.Moreover,the administration route of low-dose intravenous injection combined with nebulization shows better therapeutic effects and lower adverse reactions,providing new ideas for clinical administration.

Different efficiency toward the biomimetic aerobic oxidation of benzyl alcohol in microchannel and bubble column reactors: Hydrodynamic characteristics and gas–liquid mass transfer

The selective aerobic oxidation of benzyl alcohol to benzaldehyde has attracted considerable attention because benzaldehyde is a high value-added product. The rate of this typical gas–liquid reaction is significantly affected by mass transfer. In this study, CoTPP-mediated(CoTPP: cobalt(II) mesotetraphenylporphyrin) selective benzyl alcohol oxidation with oxygen was conducted in a membrane microchannel(MMC) reactor and a bubble column(BC) reactor, respectively. We observed that 83% benzyl alcohol was converted within 6.5 min in the MMC reactor, but only less than 10% benzyl alcohol was converted in the BC reactor. Hydrodynamic characteristics and gas–liquid mass transfer performances were compared for the MMC and BC reactors. The MMC reactor was assumed to be a plug flow reactor,and the dimensionless variance was 0.29. Compared to the BC reactor, the gas–liquid mass transfer was intensified significantly in MMC reactor. It could be ascribed to the high gas holdup(2.9 times higher than that of BC reactor), liquid film mass transfer coefficient(8.2 times higher than that of BC reactor), and mass transfer coefficient per unit interfacial area(3.8 times higher than that of BC reactor). Moreover,the Hatta number for the MMC reactor reached up to 0.61, which was about 15 times higher than that of the BC reactor. The computational fluid dynamics calculations for mass fractions in both liquid and gas phases were consistent with the experimental data.

Prevention against diffuse spinal cord astrocytoma: can the Notch pathway be a novel treatment target?

This study was designed to investigate whether the Notch pathway is involved in the develop-ment of diffuse spinal cord astrocytomas. BALB/c nude mice received injections of CD133＋and CD133？ cell suspensions prepared using human recurrent diffuse spinal cord astrocytoma tissue through administration into the right parietal lobe. After 7–11 weeks, magnetic resonance imaging was performed weekly. Xenografts were observed on the surfaces of the brains of mice receiving the CD133＋ cell suspension, and Notch-immunopositive expression was observed in the xenografts. By contrast, no xenografts appeared in the identical position on the surfaces of the brains of mice receiving the CD133？ cell suspension, and Notch-immunopositive expres-sion was hardly detected either. Hematoxylin-eosin staining and immunohistochemical staining revealed xenografts on the convex surfaces of the brains of mice that underwent CD133＋ astro-cytoma transplantation. Some sporadic astroglioma cells showed pseudopodium-like structures, which extended into the cerebral white matter. However,it should be emphasized that the sub-cortex xenograft with Notch-immunopositive expression was found in the fourth mouse received injection of CD133？ astrocytoma cells. However, these ifndings suggest that the Notch pathway plays an important role in the formation of astrocytomas, and can be considered a novel treat-ment target for diffuse spinal cord astrocytoma.

Manganese porphyrin-mediated aerobic epoxidation of propylene with isoprene: A new strategy for simultaneously preparing propylene epoxide and isoprene monoxide

The direct epoxidation of propylene by O_(2) is a significant and challenging topic. The key factor for this homogeneous aerobic epoxidation is the activation of molecular oxygen under mild conditions. In this work,the aerobic epoxidation of propylene catalyzed by manganese porphyrins was achieved in the presence of isoprene. Isoprene contains an allyl methyl group, and the α-H can be easily removed to achieve the activation of molecular oxygen. The conversion of propylene was 38% and the selectivity toward propylene oxide(PO) was up to 87%. The role of isoprene was demonstrated, and a plausible mechanism was proposed. The protocol reported herein is expected to provide a strategy for the simultaneous preparation of propylene oxide and isoprene monoxide.