Breaking down the cell wall: Still an attractive antibacterial strategy.

Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.

The Assessment on Synergistic Activity of Ebselen and Silver Ion Against Yersinia pseudotuberculosis.

Yersinia pseudotuberculosis is a foodborne zoonotic bacterium that is pathogenic to guinea pigs, rabbits, and mice. It also causes pseudotuberculosis in humans. However, it still lacked the scientific basis for control. Here, we found out that Ebselen (EbSe) exhibited synergistic antibacterial activity with silver nitrate (Ag+) against Y. pseudotuberculosis YpIII strain with high efficacy in vitro using UV-visible light absorption spectrum, 5,5'-dithiobis-(2-nitrobenzoic acid), laser scanning confocal microscope, flow cytometry, transmission electron microscopy and Western blotting assays. The depletion of total glutathione (GSH) amount and inhibition of thioredoxin reductase (TrxR) activity in thiol-dependent redox system revealed the destructiveness of EbSe-Ag+-caused intracellular oxidative stress. Furthermore, a YpIII-caused mice gastroenteritis model was constructed. EbSe-Ag+ significantly reduced bacterial loads with low toxicity. It also down-regulated the expression levels of interferon (IL)-1ß and tumor necrosis factor-α, up-regulated the expression level of IL-10 on-site. All the in vivo results demonstrated the antibacterial activity and immune-modulatory property of EbSe-Ag+. Collectively, these results provided academic fundament for further analysis and development of EbSe-Ag+ as the antibacterial agents for pseudotuberculosis control.

[Image quality adapted thoracic diameters in CT coronary artery imaging].

OBJECTIVE: To evaluate the correlation between image quality and thoracic diameters, anteroposterior diameter (AP) and right-left diameter (RL) for the optimization of reducing radiation dose in coronary artery imaging with Dual-source CT. METHODS: 118 patients underwent CT coronary artery imaging (CTCA) were divided into two groups (A and B) according to body mass index (BMI). There were 58 patients in group A with BMI values > or = 25 kg/m2 and < 30 kg/m2; and 60 patients in group B with BMI values < 25 kg/m2. Scan parameters: collimation 64 X 0.6 mm, reconstruction slice thickness 0.75 mm, reconstructin interval 0.7 mm, FOV 150-180 mm, the pitch adjusted according to heart rate automatically. CT imagings were obtained with tube voltage 100 kV, tube current 330 mAs (group A) and 100 kV, tube current 220 mAs (group B). The contrast-noise ratio (CNR), signal to noise ratio (SNR), as well as blind correlation test score values were calculated to establish the relationship among BMI, AP, RL and CNR, SNR. RESULTS: RL of five levels in groups of A, B were correlated to CNRa (P < 0.05). In group A and B (except iii, iv level of Group A), AP were associated with CNRa (P < 0.05). In addition to ii, iv level of group A, v level of group B, BMI were associated with CNRa (P < 0.05). The correlation coefficient of CNRa and RL of group A except ii level was greater than that of CNRa and AP. The correlation coefficient of CNRa, SNRa and RL of group B was greater than that of CNRa, SNRa and AP. Except iii level, the correlation coefficient of CNRa, SNRa and AP of group A was greater than that of CNRa, SNRa and BMI. Except ii level, the correlation coefficient of CNRa and AP of group B was greater than that of CNRa and BMI. CONCLUSION: Thoracic diameter of RL can be used as a guider to select the appropriate scan protocol in the coronary imaging acqusition with dual-source CT.

[The effect of the severity of congenital pectus excavatum on the cardiac morphology in children: evaluation with multislice helical CT].

This paper is aimed to evaluate the CT manifestation of congenital pectus excavatum and its effect on the cardiac morphology. CT features of 34 children with pectus excavatum were retrospectively reviewed. The Haller index (HI), CT depression index (CTDI), cardiac rotation angle (CRA), pulmonary vein angle (PVA), cardiac compression index (CCI) and cardiac asymmetry index (CAI) were measured from the images on the PACS system. The relationships among these indexes were evaluated. The HI was 4.12 +/- 1.48, the CTDI was 2.39+/- 0.70, CRA was (53.52 +/- 7.68) degrees, PVA was (66.51 +/- 11.02) degrees, CCI was 2.43 +/- 0.95, and CAI was 1.55 +/- 0.56. There was statistical significance of CCI and CAI between children with severe or slight pectus excavatum. The HI and CTDI were positively related with CCI and CAI respectively, whereas there was no statistical significance of CRA and PVA between children with severe or slight pectus excavatum. There was no statistical significance of HI, CTDI, CRA, PVA, CCI and CAI among different age groups. The morphological change of the heart compressed in children with pectus excavatum can be accurately evaluated by multislice helical CT.

Invasive intracranial aspergillosis spread by the pterygopalatine fossa in an immunocompetent patient.

Aspergillosis of the central nervous system (CNS) is an uncommon infection, mainly found in immunocompromised patients but rarely seen among immunocompetent patients. Herein we describe a 57 year-old immunocompetent man who suffered intracranial aspergillosis spread by the pterygopalatine fossa (PPF) following a tooth extraction. Based on magnetic resonance imaging (MRI) characteristics, in this report we focus on the spreading routes of CNS aspergillosis via communicative structures of the PPF, the relationship between clinical manifestations and the locations of the lesion, and propose a therapeutic strategy to improve the prognosis.

Invasive intracranial aspergillosis spread by the pterygopalatine fossa in an immunocompetent patient

Aspergillosis of the central nervous system (CNS) is an uncommon infection, mainly found in immunocompromised patients but rarely seen among immunocompetent patients. Herein we describe a 57 year-old immunocompetent man who suffered intracranial aspergillosis spread by the pterygopalatine fossa (PPF) following a tooth extraction. Based on magnetic resonance imaging (MRI) characteristics, in this report we focus on the spreading routes of CNS aspergillosis via communicative structures of the PPF, the relationship between clinical manifestations and the locations of the lesion, and propose a therapeutic strategy to improve the prognosis.