Design and Synthesis of Mandelic Acid Derivatives for Suppression of Virulence via T3SS against Citrus Canker.

Citrus canker, a highly contagious bacterial disease caused by Xanthomonas citri subsp. citri (Xcc), poses a substantial threat to citrus crops, leading to serious reductions in fruit yield and economic losses. Most commonly used bactericides against Xcc lead to the rapid development of resistant subpopulations. Therefore, it is imperative to create novel drugs, such as type III secretion system (T3SS) inhibitors, that specifically target bacterial virulence factors rather than bacterial viability. In our study, we designed and synthesized a series of mandelic acid derivatives including 2-mercapto-1,3,4-thiazole. Seven substances were found to reduce the level of transcription of hpa1 without affecting bacterial viability. In vivo bioassays indicated that compound F9 significantly inhibited hypersensitive response and pathogenicity. RT-qPCR assays showed that compound F9 visibly suppressed the expression of Xcc T3SS-related genes as well as citrus canker susceptibility gene CsLOB1. Furthermore, the combination with compound F9 and quorum-quenching bacteria HN-8 can also obviously alleviate canker symptoms.

Analysis of the difference in pulse oxygen saturation between the ventral and dorsal fingers.

AIM: This study aimed to investigate the effect of different probe placements on the ventral and dorsal sides of the same finger using pulse oxygen saturation monitoring. METHODS: This clinical trial used a convenience sampling method in patients admitted to the Second Hospital of Hebei Medical University. We enrolled 1330 patients from March to July 2018, including patients who were hospitalized in the intensive care unit (n = 258) and in the general ward (n = 1072). Pulse oxygen saturation measurements obtained from the ventral and dorsal sides of the same finger were compared. This work adhered to the STROBE checklist requirements. RESULTS: We found that pulse oxygen saturation measurements between the dorsal and ventral sides of a finger were not affected by different fingers, disease types, the application of a ventilator, vasoactive drugs, the conscious state of the patient or the instrument model. CONCLUSION: Our findings suggested no significant difference in saturation measurements with variation in the placement of the pulse oxygen saturation measurement instrument between the dorsal and ventral sides of a finger, regardless of illness severity. We believe that these results could simplify the monitoring procedures performed by nurses and eliminate worries concerning the inaccuracy of data because of varied probe positions.

Association of Preadmission Statin Use and Mortality in Critically Ill Patients: A Meta-Analysis of Cohort Studies.

Background: A large number of studies have been conducted to determine whether there is an association between preadmission statin use and improvement in outcomes following critical illness, but the conclusions are quite inconsistent. Therefore, this meta-analysis aims to include the present relevant PSM researches to examine the association of preadmission use of statins with the mortality of critically ill patients. Methods: The PubMed, Web of Science, Embase electronic databases, and printed resources were searched for English articles published before March 6, 2020 on the association between preadmission statin use and mortality in critically ill patients. The included articles were analyzed in RevMan 5.3. The Newcastle-Ottawa Scale (NOS) was used to conduct quality evaluation, and random/fixed effects modeling was used to calculate the pooled ORs and 95% CIs. We also conducted subgroup analysis by outcome indicators (30-, 90-day, hospital mortality). Results: All six PSM observational studies were assessed as having a low risk of bias according to the NOS. For primary outcome-overall mortality, the pooled OR (preadmission statins use vs. no use) across the six included studies was 0.86 (95% CI, 0.76-0.97; P = 0.02). For secondary outcome-use of mechanical ventilation, the pooled OR was 0.94 (95% CI, 0.91-0.97; P = 0.0005). The corresponding pooled ORs were 0.67 (95% CI, 0.43-1.05; P = 0.08), 0.91 (95% CI, 0.83-1.01; P = 0.07), and 0.86 (95% CI, 0.83-0.89; P < 0.00001) for 30-, 90-day, and hospital mortality, respectively. Conclusions: Preadmission statin use is associated with beneficial outcomes in critical ill patients, indicating a lower short-term mortality, less use of mechanical ventilation, and an improvement in hospital survival. Further high-quality original studies or more scientific methods are needed to draw a definitive conclusion.

Comparative transcriptomics analyses of the different growth states of multidrug-resistant Acinetobacter baumannii.

Multidrug-resistant (MDR) Acinetobacter baumannii is an important bacterial pathogen commonly associated with hospital acquired infections. A. baumannii can remain viable and hence virulent in the environment for a long period of time due primarily to its ability to form biofilms. A total of 459 cases of MDR A. baumannii our hospital collected from March 2014 to March 2015 were examined in this study, and a representative isolate selected for high-throughput mRNA sequencing and comparison of gene expression profiles under the biofilm and exponential growth conditions. Our study found that the same bacteria indeed exhibited differential mRNA expression under different conditions. Compared to the rapidly growing bacteria, biofilm bacteria had 106 genes upregulated and 92 genes downregulated. Bioinformatics analyses suggested that many of these genes are involved in the formation and maintenance of biofilms, whose expression also depends on the environment and specific signaling pathways and transcription factors that are absent in the log phase bacteria. These differentially expressed mRNAs might contribute to A. baumannii's unique pathogenicity and ability to inflict chronic and recurrent infections.

[Tissue engineering study on chitosan-gelatin/hydroxyapatite composite scaffolds--osteoblasts culture].

OBJECTIVE: To investigate the behavior of rat calvarial osteoblasts cultured on chitosan-gelatin/hydroxyapatite (CS-Gel/HA) composite scaffolds. METHODS: The rat calvarial osteoblasts (the 3rd passage) were seeded at a density of 1.01 x 10(6) cells/ml onto the CS-Gel/HA composite scaffolds having porosity 85.20%, 90.40% and 95.80%. Cell number was counted after cultured for 3 days, 1 week, 2 weeks and 3 weeks. Cell proliferation, bone-like tissue formation, and mineralization were separately detected by HE, von Kossa histological staining techniques. RESULTS: The CS-Gel/HA composite scaffolds supported the attachment of seeded rat calvarial osteoblasts. Cells proliferated faster in scaffold with higher porosity 90.40% and 95.80% than scaffold with lower porosity 85.20%. The osteoblasts/scaffold constructs were feasible for mineral deposition, and bone-like tissue formation in 3 weeks. CONCLUSION: This study suggests the feasibility of using CS-Gel/HA composite scaffolds for bone tissue engineering.