Synthesis and biological evaluation of novel cYY analogues targeting Mycobacterium tuberculosis CYP121A1

The rise in multidrug resistant (MDR) cases of tuberculosis (TB) has led to the need for the development of TB drugs with different mechanisms of action. The genome sequence of Mycobacterium tuberculosis (Mtb) revealed twenty different genes coding for cytochrome P450s. CYP121A1 catalyzes a C-C crosslinking reaction of dicyclotyrosine (cYY) producing mycocyclosin and current research suggests that either mycocyclosin is essential or the overproduction of cYY is toxic to Mtb. A series of 1,4-dibenzyl-2-imidazol-1-yl-methylpiperazine derivatives were designed and synthesised as cYY mimics. The derivatives substituted in the 4-position of the phenyl rings with halides or alkyl group showed promising antimycobacterial activity (MIC 6.25 μg/mL), with the more lipophilic branched alkyl derivatives displaying optimal binding affinity with CYP121A1 (iPr KD = 1.6 μM; tBu KD = 1.2 μM). Computational studies revealed two possible binding modes within the CYP121A1 active site both of which would effectively block cYY from binding

Design and synthesis of imidazole and triazole pyrazoles as mycobacterium tuberculosis CYP121A1 inhibitors

The emergence of untreatable drug‐resistant strains of Mycobacterium tuberculosis is a major public health problem worldwide, and the identification of new efficient treatments is urgently needed. Mycobacterium tuberculosis cytochrome P450 CYP121A1 is a promising drug target for the treatment of tuberculosis owing to its essential role in mycobacterial growth. Using a rational approach, which includes molecular modelling studies, three series of azole pyrazole derivatives were designed through two synthetic pathways. The synthesized compounds were biologically evaluated for their inhibitory activity towards M. tuberculosis and their protein binding affinity (KD). Series 3 biarylpyrazole imidazole derivatives were the most effective with the isobutyl (10 f) and tert‐butyl (10 g) compounds displaying optimal activity (MIC 1.562 μg/mL, KD 0.22 μM (10 f) and 4.81 μM (10 g)). The spectroscopic data showed that all the synthesised compounds produced a type II red shift of the heme Soret band indicating either direct binding to heme iron or (where less extensive Soret shifts are observed) putative indirect binding via an interstitial water molecule. Evaluation of biological and physicochemical properties identified the following as requirements for activity: LogP >4, H‐bond acceptors/H‐bond donors 4/0, number of rotatable bonds 5–6, molecular volume >340 Å3, topological polar surface area <40 Å2

Mesenchymal Stem Cell Graft Improves Recovery after Spinal Cord Injury in Adult Rats through Neurotrophic and Pro-Angiogenic Actions

Numerous strategies have been managed to improve functional recovery after spinal cord injury (SCI) but an optimal strategy doesn't exist yet. Actually, it is the complexity of the injured spinal cord pathophysiology that begets the multifactorial approaches assessed to favour tissue protection, axonal regrowth and functional recovery. In this context, it appears that mesenchymal stem cells (MSCs) could take an interesting part. The aim of this study is to graft MSCs after a spinal cord compression injury in adult rat to assess their effect on functional recovery and to highlight their mechanisms of action. We found that in intravenously grafted animals, MSCs induce, as early as 1 week after the graft, an improvement of their open field and grid navigation scores compared to control animals. At the histological analysis of their dissected spinal cord, no MSCs were found within the host despite their BrdU labelling performed before the graft, whatever the delay observed: 7, 14 or 21 days. However, a cytokine array performed on spinal cord extracts 3 days after MSC graft reveals a significant increase of NGF expression in the injured tissue. Also, a significant tissue sparing effect of MSC graft was observed. Finally, we also show that MSCs promote vascularisation, as the density of blood vessels within the lesioned area was higher in grafted rats. In conclusion, we bring here some new evidences that MSCs most likely act throughout their secretions and not via their own integration/differentiation within the host tissue

Low Energy Lossless Image Compression Algorithm for Wireless Sensor Network (LE-LICA)

The energy consumption restricts the design of image compression algorithms in Wireless Sensor Network (WSN). The tradeoff between the decompressed image quality and energy consumption should be considered in the design. The field of image processing introduced many image compression algorithms for WSN. Joint Photographic Experts Group 2000 (JPEG2000) and Absolute Moment Block Truncation Coding (AMBTC) are examples of these algorithms. This tradeoff is considered in the design of the proposed algorithm to get Lossless image compression algorithm with a high compression rate. LE-LICA is compared with the traditional algorithms using popular metrics such as: Peak Signal to Noise Ratio (PSNR), Correlation Coefficient (CC), and energy consumption. The proposed algorithm enhances both the image quality and the energy consumption. A great challenge to reconstruct an image at the sink without lossless (the best quality) and low energy consumption at the sensor node. The results show the preference of the proposed algorithm to the others

Sexual behaviour response, testicular development and semen quality of New Zealand white rabbit bucks as influenced by dietary chitosan

The present study was conducted to determine the effects of dietary chitosan supplementation on sexual behaviour responses, testicular development, and semen quality traits of New Zealand White (NZW) rabbit bucks. Twenty-four 5-week-old rabbit bucks were used in this experiment. Animals were grouped into four equal experimental groups: the control group was fed only on a basal diet, whereas the other groups were fed the basal diet supplemented with three levels of chitosan at 0.2, 0.4, or 0.6&nbsp;g/kg, respectively. Also, bucks that received chitosan at 0.2 and 0.4&nbsp;g/kg had a significantly earlier time of sexual libido (p ≤.05) and had significantly higher ejaculate volume and sperm concentration than other groups (p ≤.001). Furthermore, basic and sexual behaviours were significantly improved in bucks fed chitosan at 0.2 and 0.4&nbsp;g/kg compared with other groups. Therefore, it could be concluded that using chitosan at 0.2 and 0.4&nbsp;g/kg enhanced sexual behaviour, improved semen quality, and reproductive efficiency in the NZW rabbit bucks

Improved analysis of antenna radiation from a circular aperture covered by a dielectric hemispherical radome shell

10.1049/ip-map:20000217IEE Proceedings: Microwaves, Antennas and Propagation1472144-150IMIP