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Antimicrobial peptide-mimicking antibacterial polymers represent a practical strategy to conquer the ever-growing threat of antimicrobial resistance. Herein, we report the syntheses and antibacterial performance of degradable amphiphilic cationic polyesters containing pendent quaternary ammonium motifs and hydrophobic alkyl or fluoroalkyl groups. These polyesters were conveniently prepared from poly(3-methylene-1,5-dioxepan-2-one) via highly efficient one-pot successive thiol-Michael addition reactions. The antibacterial activity of these polyesters against S. aureus and E. coli and their hemolytic activity toward red blood cells were evaluated; some of them showed moderate antibacterial activity and selectivity against Gram-positive S. aureus. The membrane disruption mechanism of these cationic polyesters was briefly explored by monitoring the bacteria killing kinetics and SEM observations. Moreover, the effects of cationic/hydrophobic ratio and the incorporation of fluoroalkyl groups on the antibacterial activity and selectivity of the polyesters were demonstrated.
Asunto(s)
Escherichia coli , Poliésteres , Poliésteres/química , Staphylococcus aureus , Polímeros/química , Antibacterianos/farmacologíaRESUMEN
<p><b>OBJECTIVE</b>To observe the dynamic changes of Th17/Treg balance in patients following surgical intervention for intracranial aneurysm rupture.</p><p><b>METHODS</b>The percentage of Th cells and the intracellular IL-17 level, Treg cell percentage and transforming growth factor -β1 (TGF-β1) levels were examined in 73 patients with rupture of aneurysms before and at 24 h, 72 h and 1 week after operation, with 62 patients with unruptured aneurysms and 65 healthy volunteers as the control. The correlations among the immune cells, cytokines and clinical characteristics of the patients (NIHSS, ADL and hospitalization stay) were analyzed.</p><p><b>RESULTS</b>Th17 percentage and intracellular IL-17 levels were significantly higher in the patients with ruptured and unruptured aneurysms than in the healthy volunteers, and were significantly higher in patients with ruptured aneurysms than in those with unruptured aneurysms. Treg cell percentage and TGF-β1 level were significantly lower in patients with aneurysms than in the healthy volunteers, and were lower in patients with ruptured aneurysms than in those with uruptured aneurysms (P<0.05). Patients with intracranial aneurysm rupture showed significantly increased Th17 cell percentage and IL-17 level but significantly lowered Treg cell percentage and TGF-β1 at 24 h following the surgery (P<0.05); these changes were reversed significantly at 72 h and 1 week after the surgery. Th17 cell percentage and IL-17 level were positively correlated with NIHSS and the length of postoperative hospital stay but inversely correlated with ADL; Treg cell percentage and TGF-β1 were inversely correlated with NIHSS and hospital stay but positively with ADL (P<0.05).</p><p><b>CONCLUSION</b>In patients with intracranial aneurysms, the systemic immune inflammatory response is highlighted by excessive Th17 cells and insufficient Treg cells, which are closely related with the outcomes of the patients following surgical intervention. Evaluation of Th17/Treg balance and the cytokine levels can help to assess the prognosis of patients with aneurysm rupture.</p>
Asunto(s)
Humanos , Aneurisma Roto , Alergia e Inmunología , Citometría de Flujo , Interleucina-17 , Sangre , Aneurisma Intracraneal , Alergia e Inmunología , Periodo Posoperatorio , Pronóstico , Linfocitos T Reguladores , Biología Celular , Células Th17 , Biología Celular , Factor de Crecimiento Transformador beta1 , SangreRESUMEN
<p><b>OBJECTIVE</b>To explore the relationship between serum creatinine (Scr) reference values in healthy adults and geographic factors and provide evidence for establishing Scr reference values in different regions.</p><p><b>METHODS</b>We collected 29 697 Scr reference values from healthy adults measured by 347 medical facilities from 23 provinces, 4 municipalities and 5 autonomous regions. We chose 23 geographical factors and analyzed their correlation with Scr reference values to identify the factors correlated significantly with Scr reference values. According to the Principal component analysis and Ridge regression analysis, two predictive models were constructed and the optimal model was chosen after comparison of the two model's fitting degree of predicted results and measured results. The distribution map of Scr reference values was drawn using the Kriging interpolation method.</p><p><b>RESULTS</b>Seven geographic factors, including latitude, annual sunshine duration, annual average temperature, annual average relative humidity, annual precipitation, annual temperature range and topsoil (silt) cation exchange capacity were found to correlate significantly with Scr reference values. The overall distribution of Scr reference values featured a pattern that the values were high in the south and low in the north, varying consistently with the latitude change.</p><p><b>CONCLUSION</b>The data of the geographic factors in a given region allows the prediction of the Scr values in healthy adults. Analysis of these geographical factors can facilitate the determination of the reference values specific to a region to improve the accuracy for clinical diagnoses.</p>
RESUMEN
<p><b>OBJECTIVE</b>To analyze the relationship between the reference values of fibrinogen (FIB) in healthy Chinese adults and geographical factors to provide scientific evidences for establishing the uniform standard.</p><p><b>METHODS</b>The reference values of FIB of 10701 Chinese healthy adults from 103 cities were collected to investigate their relationship with 18 geographical factors including spatial index, terrain index, climate index, and soil index. Geographical factors that significantly correlated with the reference values were selected for constructing the BP neural network model. The spatial distribution map of the reference value of FIB of healthy Chinese adults was fitted by disjunctive kriging interpolation. We used the 5-layer neural network and selected 2000 times of training covering 11 hidden layers to build the simulation rule for simulating the relationship between FIB and geographical environmental factors using the MATLAB software.</p><p><b>RESULTS</b>s The reference value of FIB in healthy Chinese adults was significantly correlated with the latitude, sunshine duration, annual average temperature, annual average relative humidity, annual precipitation, annual range of air temperature, average annual soil gravel content, and soil cation exchange capacity (silt). The artificial neural networks were created to analyze the simulation of the selected indicators of geographical factors. The spatial distribution map of the reference values of FIB in healthy Chinese adults showed a distribution pattern that FIB levels were higher in the South and lower in the North, and higher in the East and lower in the West.</p><p><b>CONCLUSION</b>When the geographical factors of a certain area are known, the reference values of FIB in healthy Chinese adults can be obtained by establishing the neural network mode or plotting the spatial distribution map.</p>