Characterization and application of a novel bioemulsifier in crude oil degradation by Acinetobacter beijerinckii ZRS.

Bioemulsifiers can be applicated in a variety of areas such as bioremediation and microbial-enhanced oil recovery. The present study was aimed at bioemulsifier production, optimization, stability studies, and applications of the bioemulsifier produced by one of these strains, Acinetobacter beijerinckii ZRS. When Acinetobacter beijerinckii ZRS is cultured with hexadecane as a carbon source, it produces a novel extracellular emulsifying agent that does not cause remarkable reductions in surface tension. In order to enhance bioemulsifier production, response surface methodology was applied to optimize the culture medium. The bioemulsifier was subjected to thin-layer chromatography, Fourier transform infrared spectroscopy (FTIR), gel filtration chromatography, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), and nuclear magnetic resonance (NMR), which allowed for the identification of a novel polymeric bioemulsifier. The bioemulsifier retained its properties at a wide range of pH values, high temperatures and high salinities (up to 5% [w/v] Na(+) and 24% Ca(2+)). To deduce the role of this bioemulsifier in a coastal zone oil spill, the propagation of oil-degrading bacteria on oil-coated grains of gravel immersed in seawater was investigated in beach-simulating tanks. The bioemulsifier played a positive role in the degradation of these hydrocarbons and increasing the light crude oil degradation rate of the bacterial strain from 37.5 to 58.3% within 56 days. Therefore, this bioemulsifier shows strong potential to be used for bioremediation of oil pollution in marine environments.

Subcutaneous continuous glucose monitoring in critically ill patients during insulin therapy: a meta-analysis.

BACKGROUND: Using continuous glucose monitoring (CGM) in critically ill adult patients requiring insulin therapy has increased with inconsistent results. Thus, we conducted a meta-analysis to assess the effect of CGM and frequent point-of-care (POC) measurements in such a patient population. METHODS: We searched PubMed, Embase, Cochrane Library, China national knowledge infrastructure, and Wanfang for relevant articles from inception to Jan 15, 2022. Randomized controlled trials (RCTs) were considered if they focused on critically ill patients who required insulin and were treated with CGM or any POC measurements. We used the Cochrane risk evaluating tool to assess study quality. Subgroup analysis and publication bias were also conducted. RESULTS: We finally included 19 RCTs with 1,852 participants. The quality of the included studies were at a low to moderate levels. Overall, CGM devices significantly reduced hypoglycemia incidence (Risk ratio (RR) 0.35; 95% CI, 0.25-0.49; P<0.00001) than the POC measurement. Further subgroup and sensitivity analyses confirmed this result. The CGM group also had lower overall mortality (RR 0.54; 95% CI, 0.34-0.86; P=0.01), lower glucose variability, and nosocomial infection. The time in, below, or above target blood glucose range, insulin use, and length of stay in the ICU were comparable between the two groups. In addition, few studies provided data in favor of decreased nursing workload and medical costs in the CGM group. CONCLUSIONS: The CGM technique could significantly reduce hypoglycemia incidence, overall mortality, and glucose variability compared to POC measurement in critically ill patients. However, further large, well-designed RCTs are required to confirm our results.

Prognostic role of bioelectrical impedance phase angle for critically ill patients: A systemic review and meta-analysis.

Objective: Bioelectrical impedance-derived phase angle (PA) has exhibited good prognostic values in several non-critical illnesses. However, its predictive value for critically ill patients remains unclear. Thus, we aimed to perform a systematic review and meta-analysis to investigate the relationship between PA and survival in such a patient population. Materials and methods: We searched for relevant studies in PubMed, Embase, and the Cochrane database up to Jan 20, 2022. Meta-analyses were performed to determine the association between the baseline PA after admission with survival. We further conducted subgroup analyses and sensitivity analyses to explore the sources of heterogeneity. Results: We included 20 studies with 3,770 patients. Patients with low PA were associated with a significantly higher mortality risk than those with normal PA (OR 2.45, 95% CI 1.97-3.05, P < 0.00001). Compared to survivors, non-survivors had lower PA values (MD 0.82°, 95% CI 0.66-0.98; P < 0.00001). Similar results were also found when pooling studies reported regression analyses of PA as continuous (OR = 0.64; 95% CI 0.52-0.79, P < 0.00001) or categorical variable (OR = 2.42; 95% CI 1.76-3.34; P < 0.00001). These results were further confirmed in subgroup analyses and sensitivity analyses. Conclusion: Our results indicated that PA may be an important prognostic factor of survival in critically ill patients and can nicely complement the deficiencies of other severity scoring systems in the ICU setting.

Clinical relevance of a CD4+ T cell immune function assay in the diagnosis of infection in pediatric living-donor liver transplantation.

The aim of the present study was to investigate the potential of the Immuknow immune cell function assay for the diagnosis of infection after pediatric living-donor liver transplantation (LDLT). Based on clinical data obtained following liver transplantation, 66 patients were divided into infection (n=28) and non-infection (n=38) groups. The following factors were considered in the present analysis: Primary disease, lymphocyte count, tacrolimus plasma concentration/dose (C0/D) ratio, CD4+ T lymphocyte ATP levels, at pre-transplant stage and at weeks 1-4, and 2 and 3 months post-transplant. The CD4+ T lymphocyte ATP values were plotted in a receiver operating characteristic (ROC) curve. The CD4+ T lymphocyte ATP value of the infection group was significantly lower compared with that of the non-infection group (188.6±93.5 vs. 424.4±198.1 ng/ml, respectively; P<0.05). No correlation was observed between the ATP value and tacrolimus plasma C0/D ratio (R2=0.0001484); however, a correlation was reported between the ATP value and lymphocyte count (R2=0.2149). Analysis of the ROC curve indicated that the ATP levels of CD4+ T cells were significantly associated with the diagnostic value of infection (area under the curve=0.866). These findings suggest that low CD4+ T lymphocyte ATP levels may be an independent risk factor for infection following pediatric LDLT, and that the Immuknow assay may be used as a tool to evaluate T lymphocyte function in such patients to predict the risk of infection.