Signature-tagged mutagenesis screening revealed the role of lipopolysaccharide biosynthesis gene rfbH in smooth-to-rough transition in Salmonella Enteritidis

Publication date: Available online 5 May 2018
Source:Microbiological Research
Author(s): Yang Jiao, Zemiao Xia, Xiaohui Zhou, Yaxin Guo, Rongxian Guo, Xilong Kang, Kaiyue Wu, Jun Sun, Xiulong Xu, Xinan Jiao, Zhiming Pan, Xiufan Liu
Salmonella enterica serovar Enteritidis (S. Enteritidis, SE) is a major cause of foodborne diseases for humans. The completeness of the O-chain antigen of Lipopolysaccharide (LPS) determines whether a S. Enteritidis strain is smooth or rough. However, genes that are involved in the synthesis of LPS and rough-smooth variation are not completely understood. In this study, we used monoclonal antibody against O-antigens (O9 mAb) to identify novel factors that are involved in LPS synthesis and rough variation in S. Enteritidis by using signature-tagged mutagenesis (STM) technique. Our results showed that transposon insertion in the gene rfbH led to different LPS phenotype, auto-aggregation characteristic, motility and resistance to environmental stress compared with SE wild-type strain C50041. In addition, sera tests showed that rfbH mutant does not elicit specific antibodies against O-antigens in vaccinated animals. Taken together, the S. Enteritidis rfbH gene is implicated in LPS biosynthesis, rough variation, sera distinguishable reaction, motility and stress resistance. The rfbH mutant strain could be potentially used as a distinguishable vaccine or a live vector to deliver drugs and antibodies in vivo.



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Diminished neural network dynamics in amnestic mild cognitive impairment

Publication date: Available online 5 May 2018
Source:International Journal of Psychophysiology
Author(s): Einat K. Brenner, Frank G. Hillary, Emily C. Grossner, Rachel A. Bernier, Nicholas Gilbert, K. Sathian, Benjamin M. Hampstead
Mild cognitive impairment (MCI) is widely regarded as an intermediate stage between typical aging and dementia, with nearly 50% of patients with amnestic MCI (aMCI) converting to Alzheimer's dementia (AD) within 30 months of follow-up (Fischer et al., 2007). The growing literature using resting-state functional magnetic resonance imaging reveals both increased and decreased connectivity in individuals with MCI and connectivity loss between the anterior and posterior components of the default mode network (DMN) throughout the course of the disease progression (Hillary et al., 2015; Sheline & Raichle, 2013; Tijms et al., 2013). In this paper, we use dynamic connectivity modeling and graph theory to identify unique brain "states," or temporal patterns of connectivity across distributed networks, that distinguish individuals with aMCI from healthy older adults (HOAs). We enrolled 44 individuals diagnosed with aMCI and 33 HOAs of comparable age and education. Our results indicated that individuals with aMCI spent significantly more time in one state in particular, whereas neural network analysis in the HOA sample revealed approximately equivalent representation across four distinct states. Among individuals with aMCI, spending a higher proportion of time in the dominant state relative to a state where participants exhibited high cost (a measure combining connectivity and distance), predicted better language performance and perseveration. This is the first report to examine neural network dynamics in individuals with aMCI.



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Editorial Board

Publication date: 15 June 2018
Source:Journal of Proteomics, Volume 181





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Brown adipose tissue in young adults who were born preterm or small for gestational age

Journal Name: Journal of Pediatric Endocrinology and Metabolism
Issue: Ahead of print


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Utilidad de la imagen combinada de PET/TC con 68Ga-DOTATOC y gammagrafía de bazo para la diferenciación entre tumor neuroendocrino de la cola del páncreas y lesiones esplénicas en un paciente con esplenosis post-traumática

Publication date: Available online 5 May 2018
Source:Revista Española de Medicina Nuclear e Imagen Molecular
Author(s): J. Maffey-Steffan, C. Uprimny, R. Moncayo, A.S. Kroiss, I.J. Virgolini




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Development of the whisker-to-barrel cortex system

Publication date: December 2018
Source:Current Opinion in Neurobiology, Volume 53
Author(s): Jenq-Wei Yang, Werner Kilb, Sergei Kirischuk, Petr Unichenko, Maik C Stüttgen, Heiko J Luhmann
This review provides an overview on the development of the rodent whisker-to-barrel cortex system from late embryonic stage to the end of the first postnatal month. During this period the system shows a remarkable transition from a mostly genetic-molecular driven generation of crude connectivity, providing the template for activity-dependent structural and functional maturation and plasticity, to the manifestation of a complex behavioral repertoire including social interactions. Spontaneous and sensory-evoked activity is present in neonatal barrel cortex and control the generation of the cortical architecture. Half a century after its first description by Woolsey and van der Loos the whisker-to-barrel cortex system with its unique and clear topographic organization still offers the exceptional opportunity to study sensory processing and complex behavior.



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Multi-kinetic release of benznidazole-loaded multiparticulate drug delivery systems based on polymethacrylate interpolyelectrolyte complexes

Publication date: 30 July 2018
Source:European Journal of Pharmaceutical Sciences, Volume 120
Author(s): Mónica C. García, Marisa Martinelli, Nicolás E. Ponce, Liliana M. Sanmarco, María P. Aoki, Rubén H. Manzo, Alvaro F. Jimenez-Kairuz
Interpolyelectrolyte complexes (IPEC) formulated as multiparticulate drug delivery systems (MDDS) are interesting carriers to improve drug' performance. Benznidazole (BZ) is the first–line drug for Chagas treatment; however, it presents side effects and toxicity, conditioning its efficacy and safety. The goal of this work was to obtain novel MDDS composed by IPEC based on different polymethacrylate carriers loaded with BZ and to investigate in vitro drug delivery performance for oral administration. Physicochemical characterizations were studied and preclinical studies in a murine model of acute Chagas disease were also performed. The MDDS composed by BZ-loaded IPEC based on polymethacrylates were obtained by casting solvent followed by wet granulation methods with yields >83%. FT-IR demonstrated ionic interaction between the polyelectrolytes. Confocal microscopy, DSC and PXRD revealed a fraction uniformly distributed of free BZ on the multiparticles. The rheological evaluation of the MDDS showed adequate flow features for their formulation in hard gelatin-capsules. The type and composition of IPEC conditioned the modulation of BZ release and fluid uptake results. MDDS based on more hydrophylic Eudragit® showed very fast dissolution (Q15min > 85%), while an extended release (Q120min ≤ 40%) for the hydrophobic ones was observed. Capsules containing a combination of two MDDS with different release profile of BZ showed promising properties to improve Chagas disease pharmacotherapy in the preliminary in vivo assay performed, in which the BZ-loaded MDDS exhibited efficacy to reduce parasitemia, while decreasing the levels of liver injury markers in comparison to BZ conventional treatment. Multi-kinetic BZ delivery systems developed are interesting pharmaceutical alternatives to improve the treatment of Chagas disease.

Graphical abstract

https://ift.tt/2woIkYz